31 lines
1.7 KiB
Markdown
31 lines
1.7 KiB
Markdown
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# ESPNOW Example
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This example shows how to use ESPNOW of wifi. Example does the following steps:
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1. Start WiFi.
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2. Initialize ESPNOW.
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3. Register ESPNOW sending or receiving callback function.
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4. Add ESPNOW peer information.
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5. Send and receive ESPNOW data.
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In order to get the MAC address of the other device, firstly send broadcast ESPNOW data to each other with 'state' set as 0. When receiving
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broadcast ESPNOW data with 'state' as 0, add the device from which the data comes to the peer list. Then start sending broadcast ESPNOW
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data with 'state' set as 1. When receiving broadcast ESPNOW data with 'state' as 1, compare the local magic number with that in the data.
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If the local one is bigger than that one, stop sending broadcast ESPNOW data and start sending unicast ESPNOW data. If receive unicast
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ESPNOW data, also stop sending broadcast ESPNOW data. That is what happens in this example. It shows how to send/receive broadcast/unicast
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ESPNOW data. In practice, if the MAC address of the other device is known, it's not required to send/receive broadcast ESPNOW data first,
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just add the device to the peer list and send/receive unicast ESPNOW data.
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There are a lot of "extras" on top of ESPNOW data, such as type, state, sequence number, CRC and magic in this example. These "extras" are
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not required to use ESPNOW. They are only used to make this example to run correctly. However, it is recommended that users add some "extras"
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to make ESPNOW data more safe and more reliable.
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*Note:* The two devices can be set as either station or softap or station+softap mode. If the receiving device is in station mode only
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and it connects to an AP, modem sleep should be disabled.
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More info in the code [espnow_example_main.c](./main/espnow_example_main.c).
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