This board is different from many Arduino boards you may have used. It took me a week or two searching the internet to learn how to get it to work. First, the battery connector is reversed polarity compared to most LIPO batteries, so you may need to swap pins on the battery connector (Red wire to + on board). To upload sketches from the Arduino IDE, you must ground GPIO 0, then press the reset button. You may need to unplug are plug in the USB cable to get this to work. The serial monitor will display "waiting for download". Then you can upload a sketch, and when finished, unground the GPIO 0 pin and press the reset button again to run the sketch. /* * There are three serial ports on the ESP known as U0UXD, U1UXD and U2UXD. * * U0UXD is used to communicate with the ESP32 for programming and during reset/boot. * U1UXD is unused and can be used for your projects. Some boards use this port for SPI Flash access though * U2UXD is unused and can be used for your projects. * */ Software Serial will not compile with this board. Instead use a hardware serial as follows: #include //required to use additional serial UART's #define RXD2 16 //Rx pin GPIO 16 #define TXD2 17 //Tx pin GPIO 17 void setup() { // Note the format for setting a serial port is as follows: Serial2.begin(baud-rate, protocol, RX pin, TX pin); Serial.begin(115200); //Serial1.begin(9600, SERIAL_8N1, RXD2, TXD2); Serial2.begin(9600, SERIAL_8N1, RXD2, TXD2); Serial.println("Serial Txd is on pin: "+String(TX)); Serial.println("Serial Rxd is on pin: "+String(RX)); } void loop() { //Choose Serial1 or Serial2 as required while (Serial2.available()) { Serial.print(char(Serial2.read())); } } /* Baud-rates available: 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, or 115200, 256000, 512000, 962100 * * Protocols available: * SERIAL_5N1 5-bit No parity 1 stop bit * SERIAL_6N1 6-bit No parity 1 stop bit * SERIAL_7N1 7-bit No parity 1 stop bit * SERIAL_8N1 (the default) 8-bit No parity 1 stop bit * SERIAL_5N2 5-bit No parity 2 stop bits * SERIAL_6N2 6-bit No parity 2 stop bits * SERIAL_7N2 7-bit No parity 2 stop bits * SERIAL_8N2 8-bit No parity 2 stop bits * SERIAL_5E1 5-bit Even parity 1 stop bit * SERIAL_6E1 6-bit Even parity 1 stop bit * SERIAL_7E1 7-bit Even parity 1 stop bit * SERIAL_8E1 8-bit Even parity 1 stop bit * SERIAL_5E2 5-bit Even parity 2 stop bit * SERIAL_6E2 6-bit Even parity 2 stop bit * SERIAL_7E2 7-bit Even parity 2 stop bit * SERIAL_8E2 8-bit Even parity 2 stop bit * SERIAL_5O1 5-bit Odd parity 1 stop bit * SERIAL_6O1 6-bit Odd parity 1 stop bit * SERIAL_7O1 7-bit Odd parity 1 stop bit * SERIAL_8O1 8-bit Odd parity 1 stop bit * SERIAL_5O2 5-bit Odd parity 2 stop bit * SERIAL_6O2 6-bit Odd parity 2 stop bit * SERIAL_7O2 7-bit Odd parity 2 stop bit * SERIAL_8O2 8-bit Odd parity 2 stop bit */
