Zumo 32U4 with XBee Wireless

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1

Hey guys,
Has anyone disconnected the LCD to free up the RX/TX pins (pins 0/1)? I want to pull wireless data from the Zumo so I am have some simple send/receive code that works fine between two Arduinos, however when I download the same code to the Zumo and turn on the AA battery power there is no transmission. This is the code running on the Zumo,

void setup() { Serial.begin(9600); } void loop() { Serial.println("H"); //turn on the LED delay(1000); Serial.println("L");//turn off the LED delay(1000); }

Connections to the Xbee are (Zumo-XBee): GND-GND, 3.3V-3.3V, TX-DIN, RX-DOUT
Those same connections work on an Arduino UNO plugged into an external power source with the same code.

Thanks!
Adam

2

Hello.

You should be able to use the hardware Serial pins normally with the LCD removed. The Zumo 32U4 uses an Atmel ATmega32U4 AVR microcontroller, so it will behave like an Arduino Leonardo with regards to Serial communication. This means that Serial commands will communicate over the USB; to send Serial commands via the RX and TX pins (0 and 1), you should be using Serial1. You can see more information about this on Arduino’s Serial reference page.

By the way, the serial signals from Zumo 32U4 will be at 5V, so you should make sure your particular Xbee module is compatible with 5V inputs. If it is not, you might consider using something like a logic level shifter between the Zumo and Xbee module.

Brandon

3

Brandon,
Thank you for your quick and detailed response.

Just for anyone else who might stumble upon this post, all I had to do was change to Serial1 and everything works as expected. Here is the modified code that now works on the Zumo:

void setup() {
Serial1.begin(9600); //For Zumo use Serial1
}
void loop() {
  Serial1.println("H"); //turn on the LED
  delay(1000);
  Serial1.println("L");//turn off the LED
  delay(1000);
}

Thank you,
Adam

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