Sleep

If you run into this problem it means that you’re probably using the XBeeShield. Maybe you didn’t notice but if you take a look to the Arduino XBee Shield schematics you’ll find out that DIO7 (CTS - Clear to Send) on the XBee is wired to RST in the Arduino. And that’s why you get the Arduino reset. Even if you set DIO7 configuration to 0 - DISABLED (using X-CTU) the DIO7 will be set to HIGH then XBee enters sleep (This is stated in the “End Device Sleep Configuration”/“XBee End Device Configuration” chapter of the XBee Manual) . ...

I’ve been playing with the Arduino sleep modes and i wanted to be able to wake up from the sleep when receiving data on the serial port. Mainly, because in my project I’m using the XBee in the API mode and the tricks exposed in http://www.arduino.cc/playground/Learning/ArduinoSleepCode and http://www.libelium.com/squidbee/index.php?title=Save_power_in_SquidBee_-_sleep_mode involve putting Arduino in SLEEP_MODE_PWR_DOWN and using an extra pin on the arduino to monitor the RX pin and detecting LOW. I didn’t like that much that solution so I started to look into other ways of doing it without using an extra pin and without risk of losing data in the serial interface. Because as I understood it using SLEEP_MODE_PWR_DOWN requires to send first a burst of data to the serial interface in order to wake up the arduino. And it takes a while for the Arduino to become fully functional so that means that you will lose/miss data in the serial interface. That was something that didn’t fit my project. ...

I just received my new MacBook Pro. I got this crash on the first day :-(. I put it to sleep and when I tried to restore… look what showed up on the screen.