The document discusses the ESP NOW protocol and its features and capabilities for wireless communication between ESP32 and ESP8266 devices. It outlines one-to-one, one-to-many, and many-to-one communication patterns for both one-way and two-way transmissions. The main steps for sending and receiving messages are described, including initializing ESP-NOW, registering callback functions, adding peer devices by MAC address, and sending/receiving messages. Important notes are provided on getting the board MAC address and the functions needed in the sender and receiver sketches.

1. ESP NOW Protocol
Prepared by
Eng. Osama Omar
Sr. Embedded SW Engineer

2. Agenda

3. Features & Capabilities

4. One to One [One Way Communication]

5. One to Many [One Way Communication]

6. Many to One [One Way Communication]

7. One to One [Two Way Communication]

8. Many to Many [Two Way Communication]

9. One to One [Two Different Boards]

10. One to Many [Two Different Boards]

11. Many to One [Two Different Boards]

12. Main Steps:

13. Differences

14. Main Functions
ESP32

15. Main Functions
ESP8266

16. Important Notes
• 1)Getting Board MAC Address
• Sender side -> Here’s what we should include in the sender sketch:
• 1)Initialize ESP-NOW;
• 2)Register a callback function upon sending data – the OnDataSent function will be executed when a message is sent. This
can tell us if the message was successfully delivered or not;
• 3)Add a peer device (the receiver). For this, you need to know the receiver MAC address;
• 4)Send a message to the peer device.
• Receiver side
• 1)Initialize ESP-NOW;
• 2)Register for a receive callback function (OnDataRecv). This is a function that will be executed when a message is
received.
• 3)Inside that callback function, save the message into a variable to execute any task with that information.

17. Any Questions?