The MXChip IoT DevKit has two UART serial ports. One is connected to the USB port and allows you to send serial data over a USB cable, such as debugging information. The other is available from Pins 1 and 2 on the finger connector and allows you to connect the device to other modules that send data over serial.
Sending data over the USB serial port
The USB serial port is available using the
Serial global variable, and this uses the
UART_0 serial port. The API for this is identical to the standard Arduino
Serial API, which you can read about in the Arduino Serial communication docs.
// Open the serial port at a speed of 115200 baud Serial.begin(115200); // Send a message over the serial connection Serial.write("Hello");
You can monitor data sent over this serial connection using the VS Code Serial Monitor, available from the command palette by selecting Arduino: Open Serial Monitor. The board will send logging information over this port in addition to the data you send.
Sending data over the finger connector serial port
The second UART serial port is available via the finger connector on the large pins 1 and 2.
|1||TX - Transmit|
|2||RX - Receive|
Pin 1 is the transmit (TX) pin, and is used to send serial data to an external module. This pin should connect to the RX pin on the external module.
Pin 2 is the receive (RX) pin, and is used to receive serial data from an external module. This pin should connect to the TX pin on the external module.
NOTE: The TX pin on the MXChip IoT DevKit needs to connect to the RX pin on an external module, and vice versa. The signal transmitted needs to go to a receiving pin.
Once the device is connected, you will need to declare a new
UARTClass variable pointing to the second serial port,
This has the same type as the
Serial global variable, and uses the same serial API.
// Open the serial port at a speed of 9600 baud Serial.begin(9600); // Read a byte from the second serial port int byte = Serial1.read(); // Send the byte to the USB serial port for debugging Serial.write(byte);