Wio with UART grove module doesnt start when usb plugged in


I have a wio tracker with grove uart bluetooth module (HM11) attached.

The tracker script doesnt start, if I plug the usb power cord. I must do a reset, bevor the script starts. I’ts only when uart module is attached.

I have made a test script, with only led use. It has no effect, if I use the SerialUSB/DBG Communication or not.

Any hints or suggestions ?

Kind regards


Hi Kai

  1. For the wio tracker, it includes the Bluetooth functions.

    <LINK_TEXT text=“http://wiki.seeedstudio.com/wio_gps_boa … connection”>http://wiki.seeedstudio.com/wio_gps_board/#bluetooth-connection</LINK_TEXT>

  2. The wio tracker uses the SerialDBG for Grove uart and SerialUSB for serial print on COM port. If you add the SerialUSB in your code, you have to open the COM port, or else, it will stuck at that line. Here is the example for Grove-UART. The Grove UART power supply is cut off by default. You have to pull pin12 high to enable the power supply. thanks.

[code]#define GrovePowerPin 12

void setup() {
pinMode(GrovePowerPin, OUTPUT);
digitalWrite(GrovePowerPin, HIGH); //power Grove
SerialDBG.begin(115200); //set Grove UART baud rate 115200

void loop() {
//SerialUSB.println(“Grove UART is sending message”);
SerialDBG.println(“This is Grove UART”);