Wixel and Arduino

Hi. I have got my Wixels up and running with an Arduino shield. All is working as promised, but I have a minor query.

The arduino is loaded with the Example Serial Communication Sketch (listen for H and L to turn the leds on and off). One wixel is on the arduino shield, the other is plugged into my Mac.

It works fine, but I have a minor issue, and I’d appreciate some enlightenment. When I open a serial terminal emulator (or otherwise open the serial port), the wixels communicate, and briefly the led on pin 13 flashes. Why? If I want to use that pin to say activate an alarm, I DON’T want serial communication triggering anything connecting to that pin.

Perhaps I should ask another way - which arduino pins can the wixel affect, and which does it leave alone?

I can’t seem to see an answer to this in the Wixel Shield document

Hi, Ralph.

I am glad you are having a lot of success with the Wixel.

When the Arduino (at least the Uno R2 I tested) resets, the bootloader blinks the LED on pin 13 a few times. The Arduino is designed so that whenever you open the serial port on the computer, it resets. You can trigger the same effect by pressing the reset button. We were careful to make sure that it still behaves that way when you are communicating wirelessly with the Wixel shield. The bootloader blinks the LED, probably to give some kind of feedback that it is in the bootloader.

You should be able to avoid this problem by using a pin the bootloader does not affect during reset.

- Ryan