A Guide to ESP-NOW: Unidirectional Communication

Understanding the ESP-NOW Protocol

• What is ESP-NOW?

  ESP-NOW is a wireless protocol developed by Espressif for low-power, low-latency communication devices based on the ESP32/ESP8266. It supports peer-to-peer communication and is ideal for IoT applications. It allows multiple devices to communicate with one another in a peer-to-peer fashion without the need for a Wi-Fi router.

• Overview of the Unidirectional Protocol

  In a unidirectional setup, one device transmits data to another without receiving any acknowledgment. This is particularly useful for scenarios where the sender only needs to broadcast information to multiple devices, such as sensor data.

How ESP-NOW Works ?

• Finding the MAC Address of the Receiver

  Every device that supports ESP-NOW has a unique MAC (Media Access Control) address, which is crucial for establishing communication. To send data to a specific device, the sender needs to know the MAC address of the receiver. This address can be found programmatically or manually by querying the device.

• Uploading the Address to the Sender

  Once the receiver’s MAC address is found, the sender’s program must be updated to include this address. This ensures that the data sent by the sender reaches the correct destination. This is typically done by configuring the sender’s code to recognize and pair with the receiver’s MAC address.

Please find attached a working prototype of the ESP-NOW protocol, including the relevant circuit diagrams and code.

Circuit Schematic

The circuit should include a test connection between two ESP8266 modules and peripherals involved.

GitHub Repository

[GitHub Code Repo Link]

Model Demonstration

Setup Summary

1. Setup Devices

   Ensure the ESP32/ESP8266 devices are properly configured and programmed to use the ESP-NOW protocol.

2. Retrieve MAC Address

   Identify the MAC address of the receiver device and input it into the sender’s configuration.

3. Implement Data Transmission

   Program the sender to transmit data using ESP-NOW and the receiver to process the data.

4. Troubleshooting

   Test the communication, resolve address mismatches, and handle errors like interference or range limitations.

References

1. Espressif ESP-NOW Documentation:

   { ESPRESSIF }

2. ESP-NOW IEEE Implementation:

   { IEEE }

3. ResearchGate’s ESP-NOW Performance Evaluation:

   { ResearchGate }

Have fun exploring and learning :)