![\"MicroPython:](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP32-ESP-NOW-MicroPython-Many-to-one-receive-data-from-multiple-boards.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nUsing Arduino IDE?<\/strong> Follow this tutorial instead: ESP-NOW with ESP32: Receive Data from Multiple Boards (many-to-one)<\/a>.<\/p>\n\n\n\n To follow this tutorial, you need MicroPython firmware installed on your ESP32 or ESP8266 boards. You also need an IDE to write and upload the code to your board. We suggest using Thonny IDE:<\/p>\n\n\n\n New to MicroPython?<\/strong> Check out our eBook: MicroPython Programming with ESP32 and ESP8266 eBook (2nd Edition)<\/a><\/p>\n\n\n\n ESP-NOW is a wireless communication protocol developed by Espressif that allows multiple ESP32 or ESP8266 boards to exchange small amounts of data without using Wi-Fi or Bluetooth. ESP-NOW does not require a full Wi-Fi connection (though the Wi-Fi controller must be turned on), making it ideal for low-power and low-latency applications like sensor networks, remote controls, or data exchange between boards.<\/p>\n\n\n ESP-NOW uses a connectionless communication model, meaning devices can send and receive data without connecting to a router or setting up an access point (unlike HTTP communication between boards). It supports unicast (sending data to a specific device using its MAC address) and broadcast (sending data to all nearby devices using a broadcast MAC address) messaging.<\/p>\n\n\n\n New to ESP-NOW?<\/strong> Read our getting started guide: MicroPython: ESP-NOW with ESP32 (Getting Started).<\/p>\n\n\n\n This tutorial shows how to set up an ESP32 board to receive data from multiple ESP32 boards via ESP-NOW communication protocol (many-to-one configuration) as shown in the following figure.<\/p>\n\n\n To follow the project in this tutorial, you’ll need the following parts:<\/p>\n\n\n\n You can use the preceding links or go directly to MakerAdvisor.com\/tools<\/a> to find all the parts for your projects at the best price!<\/p> To communicate via ESP-NOW, you need to know the MAC address of your boards. To get your board\u2019s MAC Address, you can copy the following code to Thonny IDE and run it on your board. <\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n After running the code, it should print the board’s MAC address on the shell.<\/p>\n\n\n Get the MAC address for all of your boards.<\/p>\n\n\n\n For example, in my case, I get:<\/p>\n\n\n\n For this tutorial, we’ll send data to an ESP32 receiver board (via ESP-NOW) from two different boards. You can modify this project to send data from more boards.<\/p>\n\n\n\n Each board will be identified by an ID (a number that we’ll attribute to each board:<\/p>\n\n\n\n Each sender board will send environmental data from a BME280 sensor. Wire a BME280 sensor to each of your boards. We’ll use the ESP32 default I2C pins.<\/p>\n\n\n\n Learn more about I2C with the ESP32: ESP32 I2C Communication: Set Pins, Multiple Bus Interfaces and Peripherals (Arduino IDE)<\/a>.<\/p>\n\n\n Not familiar with the BME280 with the ESP32? Read this tutorial: MicroPython: BME280 with ESP32 (Pressure, Temperature, Humidity)<\/a>.<\/p>\n\n\n\n If you’re using a different board model, the default I2C pins might be different.<\/p>\n\n\n\n The library to interface with the BME280 sensor is not part of the standard MicroPython library. So, you need to upload the library file to each of your sender boards.<\/p>\n\n\n\n 1. Copy the following code to a new file on Thonny IDE.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n 2.<\/strong> Go to File<\/strong> > Save as…<\/strong><\/p>\n\n\n 3.<\/strong> Select save to “MicroPython device<\/strong>“:<\/p>\n\n\n 4.<\/strong> Name your file as BME280.py<\/em> and press the OK button:<\/p>\n\n\n And that’s it. The library was uploaded to your board.<\/p>\n\n\n\n Repeat this process for all your sender boards.<\/p>\n\n\n\n The following code reads the data from the BME280 sensor and sends it via ESP-NOW in a JSON variable to the ESP32 Receiver board. Don’t forget to modify the code with your receiver board’s MAC address. Additionally, don’t forget to change the board ID for each of your boards.<\/p>\n\n\n\n In this code, we’re using the aioespnow module, which allows us to use ESP-NOW asynchronously. To learn more about asynchronous programming with Micropython, read the following tutorial: MicroPython: ESP32\/ESP8266 Asynchronous Programming \u2013 Run Multiple Tasks<\/a>.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Let’s take a look at how the sender board code works. Alternatively, you can skip to the next section.<\/p>\n\n\n\n Start by importing the required libraries to use ESP-NOW, the BME280 sensor, and handle JSON variables.<\/p>\n\n\n\n Give a unique ID to your board so that the receiver can easily identify it. Here, we’re just numbering the boards, but you can use a different method, like giving them a name, or simply identifying them by the MAC address (in this case, you don’t need this parameter).<\/p>\n\n\n\n Insert the receiver’s MAC address. For example, in my case, the MAC address of the receiver board is 30:AE:A4:07:0D:64<\/span>. So, I must add ot to the code in bytes like this:<\/p>\n\n\n\n We’ll send new readings via ESP-NOW every 10 seconds. You can adjust that period on the send_interval<\/span> variable.<\/p>\n\n\n\n Initialize an I2C communication on GPIOs 22 and 21. Adjust if you’re using different pins. We also initialize the BME280 sensor.<\/p>\n\n\n\n To use ESP-NOW, we need to activate the Wi-Fi interface. In the following lines, we initialize Wi-Fi and ESP-NOW communication protocol using the aioespnow<\/span> module.<\/p>\n\n\n\n In the next line, we add the receiver board as a peer. The e.add_peer(peer_mac)<\/span> function is needed for reliable unicast communication in aioespnow. It registers the receiver’s MAC address to ensure the sender can send messages to that specific board.<\/p>\n\n\n\n The following functions return the temperature and humidity from the BME280 sensor.<\/p>\n\n\n\n The functions from the BME280 library return the results with the unit character, that’s why we’re removing characters at the end of the readings.<\/p>\n\n\n\n Learn more about interfacing the BME280 with the ESP32 using MicroPython: MicroPython: BME280 with ESP32 (Pressure, Temperature, Humidity)<\/a>.<\/p>\n\n\n\n We create a function called prepare_sensor_data()<\/span> that will return a JSON variable containing the data we want to send. In this case, we’re sending the board ID, the temperature, the humidity, and the reading ID (just a number to track how many readings were taken since the program started running).<\/p>\n\n\n\n Then, we create an asynchronous function to send the ESP-NOW messages in an asynchronous way.<\/p>\n\n\n\n Then, the following function runs the send_messages<\/span> task to send data via ESP-NOW.<\/p>\n\n\n\n Finally, we start the asynchronous program.<\/p>\n\n\n\n After copying the code to Thonny IDE and making the required changes, test the code by running it on Thonny IDE.<\/p>\n\n\n\n After establishing a connection with your board, you can click on the green run button.<\/p>\n\n\n You should get something similar, as shown in the picture below, in your MicroPython shell.<\/p>\n\n\n At the moment, the delivery will fail because we haven’t set the receiver board yet.<\/p>\n\n\n\n Important note<\/strong>: just running the file with Thonny doesn\u2019t copy it permanently to the board\u2019s filesystem. This means that if you unplug it from your computer and apply power to the board, nothing will happen because it doesn\u2019t have any Python file saved on its filesystem. The Thonny IDE Run <\/em>function is useful to test the code, but if you want to upload it permanently to your board, you need to create and save a file to the board’s filesystem.<\/p>\n\n\n\n To run the code on your boards without being connected to your computer, you must upload it to the board’s filesystem with the name main.py<\/em><\/strong><\/span>.<\/p>\n\n\n\n Go to File <\/strong>> Save as..<\/strong>. MicroPython Device<\/strong>. <\/p>\n\n\n Call that file main.py<\/em><\/strong><\/span> and save it on the board.<\/p>\n\n\n Now, if you restart your board, it will start running the code. You may not be able to access the MicroPython Shell afterwards.<\/p>\n\n\n\n The ESP32 receiver board will receive the data from the different sender boards and will display it on the OLED display. In this example, we’re receiving data from two different boards<\/p>\n\n\n Wire the OLED display to your ESP32 board. We’re using the default I2C pins\u2014GPIO 22 (SCL) and GPIO21 (SDA). Adjust if you’re using an ESP32 model with a different pinout. <\/p>\n\n\n The library to interface with the OLED sensor is not part of the standard MicroPython library. So, you need to upload the library file to your receiver board.<\/p>\n\n\n\n 1. Copy the following code to a new file on Thonny IDE.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n 2<\/strong>. Go to File <\/strong>> Save <\/strong>as and select MicroPython device<\/strong>.<\/p>\n\n\n 3.<\/strong> Name the file ssd1306.py<\/em> and click OK <\/strong>to save the file on the ESP Filesystem.<\/p>\n\n\n\n And that\u2019s it. The library was uploaded to your board. Now, you can use the library functionalities in your code by importing the library.<\/p>\n\n\n\n The following code will set up your ESP32 board as an ESP-NOW receiver to get data from the other two sender boards. After receiving the data, it will be displayed on the OLED screen.<\/p>\n\n\n\n Don’t forget to modify the code to add your sender boards’ MAC addresses.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Let’s take a look at how the sender board code works. Alternatively, you can skip to the next section.<\/p>\n\n\n\n Start by importing the required libraries (make sure you uploaded the ssd1306.py<\/em> file previously to add support for interfacing with the display).<\/p>\n\n\n\n Initialize I2C communication and the OLED display with the following lines.<\/p>\n\n\n\n Initialize the WiFi interface and ESP-NOW.<\/p>\n\n\n\n Add the the sender boards as peers (it is not mandatory to add the sender boards as peers on the receiver side, but it guarantees more reliability in the communication).<\/p>\n\n\n\n Insert the sender boards’ MAC addresses in the following variables (make sure to insert the MAC address in bytes format).<\/p>\n\n\n\n Then, add them as ESP-NOW peers:<\/p>\n\n\n\n Create a dictionary to store the latest received sensor readings from each board. Saving this information in a dictionary is a great way to save all the data received in one single variable.<\/p>\n\n\n\n The update_display()<\/span> function gets the data received from each board, that is already stored in the board_readings<\/span> variable, and displays it on the OLED screen.<\/p>\n\n\n\n To learn more about interfacing the OLED with the ESP32 using MicroPython, you can check our tutorial: MicroPython: OLED Display with ESP32 and ESP8266<\/a>.<\/p>\n\n\n\n We create an asynchronous function to get and handle the messages received via ESP-NOW. <\/p>\n\n\n\n The data comes in JSON format. We first decode and parse the JSON message.<\/p>\n\n\n\n We extract each of the parameters into individual variables.<\/p>\n\n\n\n Finally, we save the data in the right place in our board_readings<\/span> dictionary according to the board’s ID.<\/p>\n\n\n\n After that, we have the board_readings<\/span> variable updated, so now we can call the updated_display()<\/span> function to update the display with the current information.<\/p>\n\n\n\n Finally, we print the received data in the MicroPython shell.<\/p>\n\n\n\n Then, the following function runs the receive_messages<\/span> task to send data via ESP-NOW.<\/p>\n\n\n\n Finally, we start the asynchronous program.<\/p>\n\n\n\n Upload and\/or run the previous code on your receiver board. If you’re connected to Thonny IDE Terminal, it will print the received data.<\/p>\n\n\n\n At the same time, it will print the readings received from each of the sender boards on the OLED screen.<\/p>\n\n\n In this tutorial, you learned how to send data from multiple ESP32 senders to one ESP32 receiver board via ESP-NOW using MicroPython. We also showed you how to send multiple data variables in JSON format and how to parse them and handle them to get the individual bits of information that we want.<\/p>\n\n\n\n The project in this tutorial can be easily adapted to add more sender boards and send any other information you want.<\/p>\n\n\n\n We hope you’ve found this guide useful. We have more ESP-NOW guides with MicroPython that you may find useful:<\/p>\n\n\n\n Finally, if you want to learn more about MicroPython, don’t forget to check out our resources:<\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" In this MicroPython guide, we\u2019ll show you how to set up an ESP32 to receive and display data from multiple ESP32 boards using the ESP-NOW communication protocol (many-to-one configuration). We’ll … <\/p>\nPrerequisites – MicroPython Firmware<\/h2>\n\n\n\n
\n
Introducing ESP-NOW<\/h2>\n\n\n\n
![\"ESP-NOW](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/01\/esp-now-logo.png?resize=300%2C75&quality=100&strip=all&ssl=1\"){kind=logo}
<\/figure><\/div>\n\n\nProject Overview<\/h2>\n\n\n\n
![\"ESP-NOW](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP32-ESP-NOW-Receive-Data-From-Multiple-Boards.png?resize=750%2C524&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n
Parts Required<\/h2>\n\n\n\n
\n
![](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2017\/10\/header-200.png?w=1200&quality=100&strip=all&ssl=1\")
<\/a><\/p>\n\n\n\nESP32: Getting Board MAC Address<\/h2>\n\n\n\n
# Rui Santos & Sara Santos - Random Nerd Tutorials\r\n# Complete project details at https:\/\/RandomNerdTutorials.com\/micropython-esp-now-esp32\/\r\n \r\nimport network\r\n\r\nwlan = network.WLAN(network.STA_IF)\r\nwlan.active(True)\r\n\r\n# Get MAC address (returns bytes)\r\nmac = wlan.config('mac')\r\n\r\n# Convert to human-readable format\r\nmac_address = ':'.join('%02x' % b for b in mac)\r\n\r\nprint("MAC Address:", mac_address)<\/code><\/pre>\n\t![\"Thonny](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/thonny-ide-get-board-mac-address.png?resize=707%2C298&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n
Preparing the Sender Boards<\/h2>\n\n\n\n
\n
![\"Two](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/Two-ESP32-Boards-with-BME280.jpg?resize=750%2C422&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nWiring the BME280 Sensor<\/h3>\n\n\n\n
![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/10\/ESP32-BME280-Sensor-Temperature-Humidity-Pressure-Wiring-Diagram-Circuit_f.png?resize=675%2C670&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nImporting the BME280 Library<\/h3>\n\n\n\n
BME280.py MicroPython Module<\/h4>\n\n\n\n
from machine import I2C\nimport time\n\n# BME280 default address.\nBME280_I2CADDR = 0x76\n\n# Operating Modes\nBME280_OSAMPLE_1 = 1\nBME280_OSAMPLE_2 = 2\nBME280_OSAMPLE_4 = 3\nBME280_OSAMPLE_8 = 4\nBME280_OSAMPLE_16 = 5\n\n# BME280 Registers\n\nBME280_REGISTER_DIG_T1 = 0x88 # Trimming parameter registers\nBME280_REGISTER_DIG_T2 = 0x8A\nBME280_REGISTER_DIG_T3 = 0x8C\n\nBME280_REGISTER_DIG_P1 = 0x8E\nBME280_REGISTER_DIG_P2 = 0x90\nBME280_REGISTER_DIG_P3 = 0x92\nBME280_REGISTER_DIG_P4 = 0x94\nBME280_REGISTER_DIG_P5 = 0x96\nBME280_REGISTER_DIG_P6 = 0x98\nBME280_REGISTER_DIG_P7 = 0x9A\nBME280_REGISTER_DIG_P8 = 0x9C\nBME280_REGISTER_DIG_P9 = 0x9E\n\nBME280_REGISTER_DIG_H1 = 0xA1\nBME280_REGISTER_DIG_H2 = 0xE1\nBME280_REGISTER_DIG_H3 = 0xE3\nBME280_REGISTER_DIG_H4 = 0xE4\nBME280_REGISTER_DIG_H5 = 0xE5\nBME280_REGISTER_DIG_H6 = 0xE6\nBME280_REGISTER_DIG_H7 = 0xE7\n\nBME280_REGISTER_CHIPID = 0xD0\nBME280_REGISTER_VERSION = 0xD1\nBME280_REGISTER_SOFTRESET = 0xE0\n\nBME280_REGISTER_CONTROL_HUM = 0xF2\nBME280_REGISTER_CONTROL = 0xF4\nBME280_REGISTER_CONFIG = 0xF5\nBME280_REGISTER_PRESSURE_DATA = 0xF7\nBME280_REGISTER_TEMP_DATA = 0xFA\nBME280_REGISTER_HUMIDITY_DATA = 0xFD\n\n\nclass Device:\n """Class for communicating with an I2C device.\n\n Allows reading and writing 8-bit, 16-bit, and byte array values to\n registers on the device."""\n\n def __init__(self, address, i2c):\n """Create an instance of the I2C device at the specified address using\n the specified I2C interface object."""\n self._address = address\n self._i2c = i2c\n\n def writeRaw8(self, value):\n """Write an 8-bit value on the bus (without register)."""\n value = value & 0xFF\n self._i2c.writeto(self._address, value)\n\n def write8(self, register, value):\n """Write an 8-bit value to the specified register."""\n b=bytearray(1)\n b[0]=value & 0xFF\n self._i2c.writeto_mem(self._address, register, b)\n\n def write16(self, register, value):\n """Write a 16-bit value to the specified register."""\n value = value & 0xFFFF\n b=bytearray(2)\n b[0]= value & 0xFF\n b[1]= (value>>8) & 0xFF\n self.i2c.writeto_mem(self._address, register, value)\n\n def readRaw8(self):\n """Read an 8-bit value on the bus (without register)."""\n return int.from_bytes(self._i2c.readfrom(self._address, 1),'little') & 0xFF\n\n def readU8(self, register):\n """Read an unsigned byte from the specified register."""\n return int.from_bytes(\n self._i2c.readfrom_mem(self._address, register, 1),'little') & 0xFF\n\n def readS8(self, register):\n """Read a signed byte from the specified register."""\n result = self.readU8(register)\n if result > 127:\n result -= 256\n return result\n\n def readU16(self, register, little_endian=True):\n """Read an unsigned 16-bit value from the specified register, with the\n specified endianness (default little endian, or least significant byte\n first)."""\n result = int.from_bytes(\n self._i2c.readfrom_mem(self._address, register, 2),'little') & 0xFFFF\n if not little_endian:\n result = ((result << 8) & 0xFF00) + (result >> 8)\n return result\n\n def readS16(self, register, little_endian=True):\n """Read a signed 16-bit value from the specified register, with the\n specified endianness (default little endian, or least significant byte\n first)."""\n result = self.readU16(register, little_endian)\n if result > 32767:\n result -= 65536\n return result\n\n def readU16LE(self, register):\n """Read an unsigned 16-bit value from the specified register, in little\n endian byte order."""\n return self.readU16(register, little_endian=True)\n\n def readU16BE(self, register):\n """Read an unsigned 16-bit value from the specified register, in big\n endian byte order."""\n return self.readU16(register, little_endian=False)\n\n def readS16LE(self, register):\n """Read a signed 16-bit value from the specified register, in little\n endian byte order."""\n return self.readS16(register, little_endian=True)\n\n def readS16BE(self, register):\n """Read a signed 16-bit value from the specified register, in big\n endian byte order."""\n return self.readS16(register, little_endian=False)\n\n\nclass BME280:\n def __init__(self, mode=BME280_OSAMPLE_1, address=BME280_I2CADDR, i2c=None,\n **kwargs):\n # Check that mode is valid.\n if mode not in [BME280_OSAMPLE_1, BME280_OSAMPLE_2, BME280_OSAMPLE_4,\n BME280_OSAMPLE_8, BME280_OSAMPLE_16]:\n raise ValueError(\n 'Unexpected mode value {0}. Set mode to one of '\n 'BME280_ULTRALOWPOWER, BME280_STANDARD, BME280_HIGHRES, or '\n 'BME280_ULTRAHIGHRES'.format(mode))\n self._mode = mode\n # Create I2C device.\n if i2c is None:\n raise ValueError('An I2C object is required.')\n self._device = Device(address, i2c)\n # Load calibration values.\n self._load_calibration()\n self._device.write8(BME280_REGISTER_CONTROL, 0x3F)\n self.t_fine = 0\n\n def _load_calibration(self):\n\n self.dig_T1 = self._device.readU16LE(BME280_REGISTER_DIG_T1)\n self.dig_T2 = self._device.readS16LE(BME280_REGISTER_DIG_T2)\n self.dig_T3 = self._device.readS16LE(BME280_REGISTER_DIG_T3)\n\n self.dig_P1 = self._device.readU16LE(BME280_REGISTER_DIG_P1)\n self.dig_P2 = self._device.readS16LE(BME280_REGISTER_DIG_P2)\n self.dig_P3 = self._device.readS16LE(BME280_REGISTER_DIG_P3)\n self.dig_P4 = self._device.readS16LE(BME280_REGISTER_DIG_P4)\n self.dig_P5 = self._device.readS16LE(BME280_REGISTER_DIG_P5)\n self.dig_P6 = self._device.readS16LE(BME280_REGISTER_DIG_P6)\n self.dig_P7 = self._device.readS16LE(BME280_REGISTER_DIG_P7)\n self.dig_P8 = self._device.readS16LE(BME280_REGISTER_DIG_P8)\n self.dig_P9 = self._device.readS16LE(BME280_REGISTER_DIG_P9)\n\n self.dig_H1 = self._device.readU8(BME280_REGISTER_DIG_H1)\n self.dig_H2 = self._device.readS16LE(BME280_REGISTER_DIG_H2)\n self.dig_H3 = self._device.readU8(BME280_REGISTER_DIG_H3)\n self.dig_H6 = self._device.readS8(BME280_REGISTER_DIG_H7)\n\n h4 = self._device.readS8(BME280_REGISTER_DIG_H4)\n h4 = (h4 << 24) >> 20\n self.dig_H4 = h4 | (self._device.readU8(BME280_REGISTER_DIG_H5) & 0x0F)\n\n h5 = self._device.readS8(BME280_REGISTER_DIG_H6)\n h5 = (h5 << 24) >> 20\n self.dig_H5 = h5 | (\n self._device.readU8(BME280_REGISTER_DIG_H5) >> 4 & 0x0F)\n\n def read_raw_temp(self):\n """Reads the raw (uncompensated) temperature from the sensor."""\n meas = self._mode\n self._device.write8(BME280_REGISTER_CONTROL_HUM, meas)\n meas = self._mode << 5 | self._mode << 2 | 1\n self._device.write8(BME280_REGISTER_CONTROL, meas)\n sleep_time = 1250 + 2300 * (1 << self._mode)\n\n sleep_time = sleep_time + 2300 * (1 << self._mode) + 575\n sleep_time = sleep_time + 2300 * (1 << self._mode) + 575\n time.sleep_us(sleep_time) # Wait the required time\n msb = self._device.readU8(BME280_REGISTER_TEMP_DATA)\n lsb = self._device.readU8(BME280_REGISTER_TEMP_DATA + 1)\n xlsb = self._device.readU8(BME280_REGISTER_TEMP_DATA + 2)\n raw = ((msb << 16) | (lsb << 8) | xlsb) >> 4\n return raw\n\n def read_raw_pressure(self):\n """Reads the raw (uncompensated) pressure level from the sensor."""\n """Assumes that the temperature has already been read """\n """i.e. that enough delay has been provided"""\n msb = self._device.readU8(BME280_REGISTER_PRESSURE_DATA)\n lsb = self._device.readU8(BME280_REGISTER_PRESSURE_DATA + 1)\n xlsb = self._device.readU8(BME280_REGISTER_PRESSURE_DATA + 2)\n raw = ((msb << 16) | (lsb << 8) | xlsb) >> 4\n return raw\n\n def read_raw_humidity(self):\n """Assumes that the temperature has already been read """\n """i.e. that enough delay has been provided"""\n msb = self._device.readU8(BME280_REGISTER_HUMIDITY_DATA)\n lsb = self._device.readU8(BME280_REGISTER_HUMIDITY_DATA + 1)\n raw = (msb << 8) | lsb\n return raw\n\n def read_temperature(self):\n """Get the compensated temperature in 0.01 of a degree celsius."""\n adc = self.read_raw_temp()\n var1 = ((adc >> 3) - (self.dig_T1 << 1)) * (self.dig_T2 >> 11)\n var2 = ((\n (((adc >> 4) - self.dig_T1) * ((adc >> 4) - self.dig_T1)) >> 12) *\n self.dig_T3) >> 14\n self.t_fine = var1 + var2\n return (self.t_fine * 5 + 128) >> 8\n\n def read_pressure(self):\n """Gets the compensated pressure in Pascals."""\n adc = self.read_raw_pressure()\n var1 = self.t_fine - 128000\n var2 = var1 * var1 * self.dig_P6\n var2 = var2 + ((var1 * self.dig_P5) << 17)\n var2 = var2 + (self.dig_P4 << 35)\n var1 = (((var1 * var1 * self.dig_P3) >> 8) +\n ((var1 * self.dig_P2) >> 12))\n var1 = (((1 << 47) + var1) * self.dig_P1) >> 33\n if var1 == 0:\n return 0\n p = 1048576 - adc\n p = (((p << 31) - var2) * 3125) \/\/ var1\n var1 = (self.dig_P9 * (p >> 13) * (p >> 13)) >> 25\n var2 = (self.dig_P8 * p) >> 19\n return ((p + var1 + var2) >> 8) + (self.dig_P7 << 4)\n\n def read_humidity(self):\n adc = self.read_raw_humidity()\n # print 'Raw humidity = {0:d}'.format (adc)\n h = self.t_fine - 76800\n h = (((((adc << 14) - (self.dig_H4 << 20) - (self.dig_H5 * h)) +\n 16384) >> 15) * (((((((h * self.dig_H6) >> 10) * (((h *\n self.dig_H3) >> 11) + 32768)) >> 10) + 2097152) *\n self.dig_H2 + 8192) >> 14))\n h = h - (((((h >> 15) * (h >> 15)) >> 7) * self.dig_H1) >> 4)\n h = 0 if h < 0 else h\n h = 419430400 if h > 419430400 else h\n return h >> 12\n\n @property\n def temperature(self):\n "Return the temperature in degrees."\n t = self.read_temperature()\n ti = t \/\/ 100\n td = t - ti * 100\n return "{}.{:02d}C".format(ti, td)\n\n @property\n def pressure(self):\n "Return the temperature in hPa."\n p = self.read_pressure() \/\/ 256\n pi = p \/\/ 100\n pd = p - pi * 100\n return "{}.{:02d}hPa".format(pi, pd)\n\n @property\n def humidity(self):\n "Return the humidity in percent."\n h = self.read_humidity()\n hi = h \/\/ 1024\n hd = h * 100 \/\/ 1024 - hi * 100\n return "{}.{:02d}%".format(hi, hd)\n<\/code><\/pre>\n\t![\"Thonny](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/10\/Thonny-IDE-ESP32-ESP8266-MicroPython-Save-file-library-to-device-save-as.png?resize=206%2C294&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"Thonny](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/10\/Thonny-IDE-ESP32-ESP8266-MicroPython-Save-file-library-to-device-select.png?resize=220%2C202&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"BME280](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2020\/10\/bme280-library-new-MicroPython-file-Thonny-IDE.png?resize=553%2C277&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nESP32 ESP-NOW Sender – MicroPython Script<\/h3>\n\n\n\n
# Rui Santos & Sara Santos - Random Nerd Tutorials\n# Complete project details at https:\/\/RandomNerdTutorials.com\/micropython-esp-now-esp32-many-to-one\/\n\nimport network\nimport aioespnow\nimport asyncio\nimport time\nimport ujson\nfrom machine import Pin, I2C\nimport BME280\n\n# Board ID\nBOARD_ID = 1\n\n# Receiver's MAC address\npeer_mac = b'\\xff\\xff\\xff\\xff\\xff\\xff'\n\n# Interval for sending data (in seconds)\nsend_interval = 10 \n\n# Initialize I2C and BME280\ntry:\n i2c = I2C(0, scl=Pin(22), sda=Pin(21)) # Adjust pins as needed\n bme = BME280.BME280(i2c=i2c, address=0x76)\nexcept OSError as err:\n print("Failed to initialize BME280:", err)\n raise\n\n# Initialize Wi-Fi in station mode\nsta = network.WLAN(network.STA_IF)\ntry:\n sta.active(True)\n sta.config(channel=1) # Set channel explicitly\n sta.disconnect()\nexcept OSError as err:\n print("Failed to initialize Wi-Fi:", err)\n raise\n\n# Initialize AIOESPNow\ne = aioespnow.AIOESPNow()\ntry:\n e.active(True)\nexcept OSError as err:\n print("Failed to initialize AIOESPNow:", err)\n raise\n\n# Add peer\ntry:\n e.add_peer(peer_mac)\nexcept OSError as err:\n print("Failed to add peer:", err)\n raise\n\n# Counter for reading ID\nreading_id = 0\n\ndef read_temperature():\n try:\n return float(bme.temperature[:-1]) # Remove 'C' from string\n except Exception as err:\n print("Error reading temperature:", err)\n return 0.0\n\ndef read_humidity():\n try:\n return float(bme.humidity[:-1]) # Remove '%' from string\n except Exception as err:\n print("Error reading humidity:", err)\n return 0.0\n\ndef prepare_sensor_data():\n global reading_id\n data = {\n 'id': BOARD_ID,\n 'temp': read_temperature(),\n 'hum': read_humidity(),\n 'readingId': reading_id\n }\n reading_id += 1\n # Serialize to JSON and encode to bytes\n return ujson.dumps(data).encode('utf-8')\n\nasync def send_messages(e, peer):\n while True:\n try:\n # Prepare and serialize sensor data\n message = prepare_sensor_data()\n # Send JSON bytes\n if await e.asend(peer, message, sync=True):\n print(f"Sent data: {message.decode('utf-8')}")\n else:\n print("Failed to send data")\n except OSError as err:\n print("Send error:", err)\n await asyncio.sleep(5)\n await asyncio.sleep(send_interval) # Wait before next send\n\nasync def main(e, peer):\n try:\n await send_messages(e, peer)\n except Exception as err:\n print(f"Error in main: {err}")\n await asyncio.sleep(5)\n raise\n\n# Run the async program\ntry:\n asyncio.run(main(e, peer_mac))\nexcept KeyboardInterrupt:\n print("Stopping sender...")\n e.active(False)\n sta.active(False)\n<\/code><\/pre>\n\tHow Does the Code Work?<\/h3>\n\n\n\n
Importing Libraries<\/h4>\n\n\n\n
import network\nimport aioespnow\nimport asyncio\nimport time\nimport ujson\nfrom machine import Pin, I2C\nimport BME280<\/code><\/pre>\n\n\n\nSetting the Board ID<\/h4>\n\n\n\n
# Board ID\nBOARD_ID = 2<\/code><\/pre>\n\n\n\nReceiver’s MAC Address<\/h4>\n\n\n\n
# Receiver's MAC address\npeer_mac = b'\\x30\\xae\\xa4\\x07\\x0d\\x64'<\/code><\/pre>\n\n\n\nSending Interval<\/h4>\n\n\n\n
# Interval for sending data (in seconds)\nsend_interval = 10 <\/code><\/pre>\n\n\n\nInitialize the BME280 Sensor<\/h4>\n\n\n\n
# Initialize I2C and BME280\ntry:\n i2c = I2C(0, scl=Pin(22), sda=Pin(21)) # Adjust pins as needed\n bme = BME280.BME280(i2c=i2c, address=0x76)\nexcept OSError as err:\n print(\"Failed to initialize BME280:\", err)\n raise<\/code><\/pre>\n\n\n\nInitialize Wi-Fi Interface and ESP-NOW<\/h4>\n\n\n\n
# Initialize Wi-Fi in station mode\nsta = network.WLAN(network.STA_IF)\ntry:\n sta.active(True)\n sta.config(channel=1) # Set channel explicitly\n sta.disconnect()\nexcept OSError as err:\n print(\"Failed to initialize Wi-Fi:\", err)\n raise\n\n# Initialize AIOESPNow\ne = aioespnow.AIOESPNow()\ntry:\n e.active(True)\nexcept OSError as err:\n print(\"Failed to initialize AIOESPNow:\", err)\n raise<\/code><\/pre>\n\n\n\nAdd Peers<\/h4>\n\n\n\n
# Add peer\ntry:\n e.add_peer(peer_mac)\nexcept OSError as err:\n print(\"Failed to add peer:\", err)\n raise<\/code><\/pre>\n\n\n\nGetting BME280 Sensor Data<\/h4>\n\n\n\n
def read_temperature():\n try:\n return float(bme.temperature[:-1]) # Remove 'C' from string\n except Exception as err:\n print(\"Error reading temperature:\", err)\n return 0.0\n\ndef read_humidity():\n try:\n return float(bme.humidity[:-1]) # Remove '%' from string\n except Exception as err:\n print(\"Error reading humidity:\", err)\n return 0.0<\/code><\/pre>\n\n\n\nAdding the Data to a JSON Variable<\/h4>\n\n\n\n
def prepare_sensor_data():\n global reading_id\n data = {\n 'id': BOARD_ID,\n 'temp': read_temperature(),\n 'hum': read_humidity(),\n 'readingId': reading_id\n }\n reading_id += 1\n # Serialize to JSON and encode to bytes\n return ujson.dumps(data).encode('utf-8')<\/code><\/pre>\n\n\n\nSending Messages via ESP-NOW<\/h4>\n\n\n\n
async def send_messages(e, peer):\n while True:\n try:\n # Prepare and serialize sensor data\n message = prepare_sensor_data()\n # Send JSON bytes\n if await e.asend(peer, message, sync=True):\n print(f\"Sent data: {message.decode('utf-8')}\")\n else:\n print(\"Failed to send data\")\n except OSError as err:\n print(\"Send error:\", err)\n await asyncio.sleep(5)\n await asyncio.sleep(send_interval) # Wait before next send<\/code><\/pre>\n\n\n\nRunning the Asynchronous Tasks<\/h4>\n\n\n\n
async def main(e, peer):\n try:\n await send_messages(e, peer)\n except Exception as err:\n print(f\"Error in main: {err}\")\n await asyncio.sleep(5)\n raise<\/code><\/pre>\n\n\n\n# Run the async program\ntry:\n asyncio.run(main(e, peer_mac))\nexcept KeyboardInterrupt:\n print(\"Stopping sender...\")\n e.active(False)\n sta.active(False)<\/code><\/pre>\n\n\n\nRunning and Uploading the Code to Your Boards<\/h3>\n\n\n\n
![\"Thonny](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2023\/12\/thonny-ide-run-button.png?resize=470%2C114&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP32-Sender-ESP-NOW-Failed-To-Send-Terminal.png?resize=690%2C317&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nUploading the Code to Your Boards<\/h4>\n\n\n\n
<\/figure><\/div>\n\n\n![\"Uploading](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/save-to-micropython-device-main-file.png?resize=545%2C327&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nPreparing the Receiver Board<\/h2>\n\n\n\n
![\"ESP-NOW](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP-NOW-MicroPython-Many-to-one-setup-f.jpg?resize=750%2C562&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nWiring the OLED Display<\/h3>\n\n\n\n
![\"Esp32](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/05\/ESP32_OLED.png?resize=873%2C685&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nImporting the SSD1306 Library<\/h3>\n\n\n\n
SSD1306.py MicroPython Module<\/h4>\n\n\n\n
# MicroPython SSD1306 OLED driver, I2C and SPI interfaces created by Adafruit\n\nimport time\nimport framebuf\n\n# register definitions\nSET_CONTRAST = const(0x81)\nSET_ENTIRE_ON = const(0xa4)\nSET_NORM_INV = const(0xa6)\nSET_DISP = const(0xae)\nSET_MEM_ADDR = const(0x20)\nSET_COL_ADDR = const(0x21)\nSET_PAGE_ADDR = const(0x22)\nSET_DISP_START_LINE = const(0x40)\nSET_SEG_REMAP = const(0xa0)\nSET_MUX_RATIO = const(0xa8)\nSET_COM_OUT_DIR = const(0xc0)\nSET_DISP_OFFSET = const(0xd3)\nSET_COM_PIN_CFG = const(0xda)\nSET_DISP_CLK_DIV = const(0xd5)\nSET_PRECHARGE = const(0xd9)\nSET_VCOM_DESEL = const(0xdb)\nSET_CHARGE_PUMP = const(0x8d)\n\n\nclass SSD1306:\n def __init__(self, width, height, external_vcc):\n self.width = width\n self.height = height\n self.external_vcc = external_vcc\n self.pages = self.height \/\/ 8\n # Note the subclass must initialize self.framebuf to a framebuffer.\n # This is necessary because the underlying data buffer is different\n # between I2C and SPI implementations (I2C needs an extra byte).\n self.poweron()\n self.init_display()\n\n def init_display(self):\n for cmd in (\n SET_DISP | 0x00, # off\n # address setting\n SET_MEM_ADDR, 0x00, # horizontal\n # resolution and layout\n SET_DISP_START_LINE | 0x00,\n SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0\n SET_MUX_RATIO, self.height - 1,\n SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0\n SET_DISP_OFFSET, 0x00,\n SET_COM_PIN_CFG, 0x02 if self.height == 32 else 0x12,\n # timing and driving scheme\n SET_DISP_CLK_DIV, 0x80,\n SET_PRECHARGE, 0x22 if self.external_vcc else 0xf1,\n SET_VCOM_DESEL, 0x30, # 0.83*Vcc\n # display\n SET_CONTRAST, 0xff, # maximum\n SET_ENTIRE_ON, # output follows RAM contents\n SET_NORM_INV, # not inverted\n # charge pump\n SET_CHARGE_PUMP, 0x10 if self.external_vcc else 0x14,\n SET_DISP | 0x01): # on\n self.write_cmd(cmd)\n self.fill(0)\n self.show()\n\n def poweroff(self):\n self.write_cmd(SET_DISP | 0x00)\n\n def contrast(self, contrast):\n self.write_cmd(SET_CONTRAST)\n self.write_cmd(contrast)\n\n def invert(self, invert):\n self.write_cmd(SET_NORM_INV | (invert & 1))\n\n def show(self):\n x0 = 0\n x1 = self.width - 1\n if self.width == 64:\n # displays with width of 64 pixels are shifted by 32\n x0 += 32\n x1 += 32\n self.write_cmd(SET_COL_ADDR)\n self.write_cmd(x0)\n self.write_cmd(x1)\n self.write_cmd(SET_PAGE_ADDR)\n self.write_cmd(0)\n self.write_cmd(self.pages - 1)\n self.write_framebuf()\n\n def fill(self, col):\n self.framebuf.fill(col)\n\n def pixel(self, x, y, col):\n self.framebuf.pixel(x, y, col)\n\n def scroll(self, dx, dy):\n self.framebuf.scroll(dx, dy)\n\n def text(self, string, x, y, col=1):\n self.framebuf.text(string, x, y, col)\n\n\nclass SSD1306_I2C(SSD1306):\n def __init__(self, width, height, i2c, addr=0x3c, external_vcc=False):\n self.i2c = i2c\n self.addr = addr\n self.temp = bytearray(2)\n # Add an extra byte to the data buffer to hold an I2C data\/command byte\n # to use hardware-compatible I2C transactions. A memoryview of the\n # buffer is used to mask this byte from the framebuffer operations\n # (without a major memory hit as memoryview doesn't copy to a separate\n # buffer).\n self.buffer = bytearray(((height \/\/ 8) * width) + 1)\n self.buffer[0] = 0x40 # Set first byte of data buffer to Co=0, D\/C=1\n self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)\n super().__init__(width, height, external_vcc)\n\n def write_cmd(self, cmd):\n self.temp[0] = 0x80 # Co=1, D\/C#=0\n self.temp[1] = cmd\n self.i2c.writeto(self.addr, self.temp)\n\n def write_framebuf(self):\n # Blast out the frame buffer using a single I2C transaction to support\n # hardware I2C interfaces.\n self.i2c.writeto(self.addr, self.buffer)\n\n def poweron(self):\n pass\n\n\nclass SSD1306_SPI(SSD1306):\n def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):\n self.rate = 10 * 1024 * 1024\n dc.init(dc.OUT, value=0)\n res.init(res.OUT, value=0)\n cs.init(cs.OUT, value=1)\n self.spi = spi\n self.dc = dc\n self.res = res\n self.cs = cs\n self.buffer = bytearray((height \/\/ 8) * width)\n self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)\n super().__init__(width, height, external_vcc)\n\n def write_cmd(self, cmd):\n self.spi.init(baudrate=self.rate, polarity=0, phase=0)\n self.cs.high()\n self.dc.low()\n self.cs.low()\n self.spi.write(bytearray([cmd]))\n self.cs.high()\n\n def write_framebuf(self):\n self.spi.init(baudrate=self.rate, polarity=0, phase=0)\n self.cs.high()\n self.dc.high()\n self.cs.low()\n self.spi.write(self.buffer)\n self.cs.high()\n\n def poweron(self):\n self.res.high()\n time.sleep_ms(1)\n self.res.low()\n time.sleep_ms(10)\n self.res.high()\n<\/code><\/pre>\n\t<\/figure><\/div>\n\n\nESP-NOW Receiver Board – MicroPython Script<\/h3>\n\n\n\n
# Rui Santos & Sara Santos - Random Nerd Tutorials\n# Complete project details at https:\/\/RandomNerdTutorials.com\/micropython-esp-now-esp32-many-to-one\/\n\nimport network\nimport aioespnow\nimport asyncio\nimport ujson\nfrom machine import Pin, I2C\nimport ssd1306\n\n# Initialize I2C for OLED\ntry:\n i2c = I2C(0, scl=Pin(22), sda=Pin(21)) # Adjust pins as needed\n display = ssd1306.SSD1306_I2C(128, 64, i2c, addr=0x3C)\n print("SSD1306 initialized")\nexcept Exception as err:\n print("Failed to initialize SSD1306:", err)\n raise\n\n# Initialize Wi-Fi in station mode\nsta = network.WLAN(network.STA_IF)\ntry:\n sta.active(True)\n sta.config(channel=1) # Set channel explicitly\n sta.disconnect()\nexcept OSError as err:\n print("Failed to initialize Wi-Fi:", err)\n raise\n\n# Initialize AIOESPNow\ne = aioespnow.AIOESPNow()\ntry:\n e.active(True)\nexcept OSError as err:\n print("Failed to initialize AIOESPNow:", err)\n raise\n\n# Sender's MAC addresses (replace with actual sender MACs)\nsender_mac_1 = b'\\x24\\x0a\\xc4\\x31\\x40\\x50' # First sender's MAC (Board ID=1)\nsender_mac_2 = b'\\x30\\xae\\xa4\\xf6\\x7d\\x4c' # Second sender's MAC (Board ID=2)\n\n# Add peers\ntry:\n e.add_peer(sender_mac_1)\nexcept OSError as err:\n print(f"Failed to add peer {sender_mac_1.hex()}:", err)\n raise\n\ntry:\n e.add_peer(sender_mac_2)\nexcept OSError as err:\n print(f"Failed to add peer {sender_mac_2.hex()}:", err)\n raise\n\n# Dictionary to store latest readings for each board\nboard_readings = {\n 1: {'temp': 0.0, 'hum': 0.0, 'readingId': 0},\n 2: {'temp': 0.0, 'hum': 0.0, 'readingId': 0}\n}\n\n# Update OLED display with temperature and humidity for both boards on separate lines.\ndef update_display():\n try:\n display.fill(0)\n # Board 1 data\n display.text("Board 1:", 0, 0)\n display.text(f"Temp: {board_readings[1]['temp']:.1f} C", 0, 10)\n display.text(f"Hum: {board_readings[1]['hum']:.1f} %", 0, 20)\n # Board 2 data\n display.text("Board 2:", 0, 32)\n display.text(f"Temp: {board_readings[2]['temp']:.1f} C", 0, 42)\n display.text(f"Hum: {board_readings[2]['hum']:.1f} %", 0, 52)\n display.show()\n print("Display updated")\n except Exception as err:\n print("Error updating display:", err)\n\n# Async function to receive and process messages.\nasync def receive_messages(e):\n print("Listening for ESP-NOW messages...")\n while True:\n try:\n async for mac, msg in e:\n try:\n # Decode and parse JSON message\n json_str = msg.decode('utf-8')\n data = ujson.loads(json_str)\n \n # Extract parameters\n board_id = data['id']\n temperature = data['temp']\n humidity = data['hum']\n reading_id = data['readingId']\n \n # Store in board_readings dictionary\n if board_id in (1, 2):\n board_readings[board_id] = {\n 'temp': temperature,\n 'hum': humidity,\n 'readingId': reading_id\n }\n # Update OLED display\n update_display()\n \n # Display on MicroPython terminal\n print(f"\\nReceived from {mac.hex()}:")\n print(f" Board ID: {board_id}")\n print(f" Temperature: {temperature} C")\n print(f" Humidity: {humidity} %")\n print(f" Reading ID: {reading_id}")\n except (ValueError, KeyError) as err:\n print(f"Error parsing JSON: {err}")\n except OSError as err:\n print("Receive error:", err)\n await asyncio.sleep(5)\n\nasync def main(e):\n await receive_messages(e)\n\n# Run the async program\ntry:\n asyncio.run(main(e))\nexcept KeyboardInterrupt:\n print("Stopping receiver...")\n e.active(False)\n sta.active(False)\n<\/code><\/pre>\n\tHow Does the Code Work?<\/h3>\n\n\n\n
Importing Libraries<\/h4>\n\n\n\n
import network\nimport aioespnow\nimport asyncio\nimport ujson\nfrom machine import Pin, I2C\nimport ssd1306<\/code><\/pre>\n\n\n\nInitializing the OLED Display<\/h4>\n\n\n\n
# Initialize I2C for OLED\ntry:\n i2c = I2C(0, scl=Pin(22), sda=Pin(21)) # Adjust pins as needed\n display = ssd1306.SSD1306_I2C(128, 64, i2c, addr=0x3C)\n print(\"SSD1306 initialized\")\nexcept Exception as err:\n print(\"Failed to initialize SSD1306:\", err)\n raise<\/code><\/pre>\n\n\n\nInitializing the WiFi Interface and ESP-NOW<\/h4>\n\n\n\n
# Initialize Wi-Fi in station mode\nsta = network.WLAN(network.STA_IF)\ntry:\n sta.active(True)\n sta.config(channel=1) # Set channel explicitly\n sta.disconnect()\nexcept OSError as err:\n print(\"Failed to initialize Wi-Fi:\", err)\n raise\n\n# Initialize AIOESPNow\ne = aioespnow.AIOESPNow()\ntry:\n e.active(True)\nexcept OSError as err:\n print(\"Failed to initialize AIOESPNow:\", err)\n raise<\/code><\/pre>\n\n\n\nAdding the Sender Boards as Peers<\/h4>\n\n\n\n
# Sender's MAC addresses (replace with actual sender MACs)\nsender_mac_1 = b'\\x24\\x0a\\xc4\\x31\\x40\\x50' # First sender's MAC (Board ID=1)\nsender_mac_2 = b'\\x30\\xae\\xa4\\xf6\\x7d\\x4c' # Second sender's MAC (Board ID=2)<\/code><\/pre>\n\n\n\n# Add peers\ntry:\n e.add_peer(sender_mac_1)\nexcept OSError as err:\n print(f\"Failed to add peer {sender_mac_1.hex()}:\", err)\n raise\n\ntry:\n e.add_peer(sender_mac_2)\nexcept OSError as err:\n print(f\"Failed to add peer {sender_mac_2.hex()}:\", err)\n raise<\/code><\/pre>\n\n\n\nDictionary to Save the Readings<\/h4>\n\n\n\n
board_readings = {\n 1: {'temp': 0.0, 'hum': 0.0, 'readingId': 0},\n 2: {'temp': 0.0, 'hum': 0.0, 'readingId': 0}\n}<\/code><\/pre>\n\n\n\nUpdating the Display<\/h4>\n\n\n\n
def update_display():\n try:\n display.fill(0)\n # Board 1 data\n display.text(\"Board 1:\", 0, 0)\n display.text(f\"Temp: {board_readings[1]['temp']:.1f} C\", 0, 10)\n display.text(f\"Hum: {board_readings[1]['hum']:.1f} %\", 0, 20)\n # Board 2 data\n display.text(\"Board 2:\", 0, 32)\n display.text(f\"Temp: {board_readings[2]['temp']:.1f} C\", 0, 42)\n display.text(f\"Hum: {board_readings[2]['hum']:.1f} %\", 0, 52)\n display.show()\n print(\"Display updated\")\n except Exception as err:\n print(\"Error updating display:\", err)<\/code><\/pre>\n\n\n\nReceiving ESP-NOW Messages<\/h4>\n\n\n\n
async def receive_messages(e):\n print(\"Listening for ESP-NOW messages...\")\n while True:\n try:\n async for mac, msg in e:<\/code><\/pre>\n\n\n\ntry:\n # Decode and parse JSON message\n json_str = msg.decode('utf-8')\n data = ujson.loads(json_str)<\/code><\/pre>\n\n\n\n# Extract parameters into individual variables\nboard_id = data['id']\ntemperature = data['temp']\nhumidity = data['hum']\nreading_id = data['readingId']<\/code><\/pre>\n\n\n\n# Store in board_readings dictionary\nif board_id in (1, 2):\n board_readings[board_id] = {\n 'temp': temperature,\n 'hum': humidity,\n 'readingId': reading_id\n}<\/code><\/pre>\n\n\n\nupdate_display()<\/code><\/pre>\n\n\n\n# Display on serial monitor\nprint(f\"\\nReceived from {mac.hex()}:\")\nprint(f\" Board ID: {board_id}\")\nprint(f\" Temperature: {temperature} C\")\nprint(f\" Humidity: {humidity} %\")\nprint(f\" Reading ID: {reading_id}\")<\/code><\/pre>\n\n\n\nRunning the Asynchronous Tasks<\/h4>\n\n\n\n
async def main(e):\n await receive_messages(e)<\/code><\/pre>\n\n\n\n# Run the async program\ntry:\n asyncio.run(main(e, peer_mac))\nexcept KeyboardInterrupt:\n print(\"Stopping sender...\")\n e.active(False)\n sta.active(False)<\/code><\/pre>\n\n\n\nDemonstration<\/h3>\n\n\n\n
![\"ESP-NOW](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP-NOW-Receiver-Displaying-Data-From-Multiple-Boards.jpg?resize=750%2C422&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\nWrapping Up<\/h2>\n\n\n\n
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