Wifi credentialing over BLE with Ionic Capacitor Bluetooth LE pllug-in
Posted: Sun Aug 15, 2021 5:56 am
Trying to send esp32 chip wifi credentials from android app (built with ionic). Using Ionic capacitor/bluetooth-le plug in to write to esp32, using the write function:
Code for BleClient.write:
How can I pass wifi credentials as value argument to the write function so it's correctly received by ESP32? On the ESP32 side, I'm using the wifi_prov_mgr example code, which in turn uses google protocol buffer (I'm very new to protobuf and don't really understand how it works). ESP uses wifi_config.c (Espressif wifi_provisioning component). When I send wifi credentials from the app using BleClient.write, it shows up in wifi_config.c as inbuf with value "wifi_ssid,wifi_password:��Z�?�Z�?" and I get error from wifi_config.c: "Unable to unpack config data".
Here's the relevant code for wifi_config.c:
I'm having a very hard time understanding how wi_fi_config_payload_unpack processes the inbuf argument. This is where the code gets into protobuf code generated by the proto files. The proto file for wifi config data looks like this:
So my question is - how do I pass the wifi credentials in BleClient.write so it is correctly recognized by wifi_config.c on the ESP32 side?
I thought about using the Android app developed by Espressif to pass wifi credentials to the ESP32 chip, but then I don't know how to integrate native Android code with ionic code, since I need my app to do more than just credential the ESP32.
Code: Select all
await BleClient.write(device.deviceId, GATT Service ID, Characteristic ID, textToDataView('wifi_ssid,wifi_password'));Code: Select all
async write(deviceId: string, service: string, characteristic: string, value: DataView): Promise<void> {
service = validateUUID(service);
characteristic = validateUUID(characteristic);
return this.queue(async () => {
if (!value?.buffer) {
throw new Error('Invalid data.');
}
let writeValue: DataView | string = value;
if (Capacitor.getPlatform() !== 'web') {
// on native we can only write strings
writeValue = dataViewToHexString(value);
}
await BluetoothLe.write({
deviceId,
service,
characteristic,
value: writeValue,
});
});
}Here's the relevant code for wifi_config.c:
Code: Select all
esp_err_t wifi_prov_config_data_handler(uint32_t session_id, const uint8_t *inbuf, ssize_t inlen, uint8_t **outbuf, ssize_t *outlen, void *priv_data)
{
ESP_LOGI(TAG ,"Wifi config payload inbuf value: %s", inbuf);
WiFiConfigPayload *req;
WiFiConfigPayload resp;
esp_err_t ret;
req = wi_fi_config_payload__unpack(NULL, inlen, inbuf);
if (!req) {
ESP_LOGE(TAG, "Unable to unpack config data");
return ESP_ERR_INVALID_ARG;
}Code: Select all
message CmdSetConfig {
bytes ssid = 1;
bytes passphrase = 2;
bytes bssid = 3;
int32 channel = 4;
}
message WiFiConfigPayload {
WiFiConfigMsgType msg = 1;
oneof payload {
CmdGetStatus cmd_get_status = 10;
RespGetStatus resp_get_status = 11;
CmdSetConfig cmd_set_config = 12;
RespSetConfig resp_set_config = 13;
CmdApplyConfig cmd_apply_config = 14;
RespApplyConfig resp_apply_config = 15;
}
}I thought about using the Android app developed by Espressif to pass wifi credentials to the ESP32 chip, but then I don't know how to integrate native Android code with ionic code, since I need my app to do more than just credential the ESP32.