GSMShieldLeonardoMega. The GSM shield communicates with an attached Arduino through the Software Serial library. By default, communication between the modem and Arduino happens on digital pins 2 and 3. On the Uno this works without modification, but to use the Leonardo or Mega boards, some slight changes are required. The GSM_TX pin, pin 2 on the shield, sends information to the Arduino. The Arduino relies on an interrupt to know when to read the information on this pin. The Leonardo and Mega do not have interrupt capabilities on pin 2. You do not need to change any code to program the shield for use with the Mega or Leonardo, the library will change the Arduino's RX pin automatically depending on the board selected in the "Tools" menu of the IDE.
Arduino Leonardo The GSM library uses digital pin 8 to communicate with the Leonardo. Bend the male header attached to pin 2 on the GSM shield to the side so it does not connect with the Leonardo. Arduino Mega Using alternate pins with the library. SWB Labs » Retransmitting Alarm System State Changes with Raspberry Pi and Arduino. I spotted a post by Lior Hass on Hackaday a little while back where he described his Alarmino project where his alarm system now connects with an Arduino and a custom board to simulate the phone line and interpret Contact-ID protocol.
He could then get the system to SMS him in the case of an alarm. In his case, he did this in lieu of using a central monitoring service and it only reported events that would have been sent to the central monitoring service. But suppose someone was using a central monitoring service and just wanted to augment the system with additional potentially detailed and configurable notifications.
System designers often choose to transmit system state through serial protocols. For instance, one such system is described here. Systems like this use a common bus between keypads and the central system with power, ground, and clock and data lines. It would be nice to make use of such system state information on computers like the Raspberry Pi.
10 Ways to Destroy an Arduino : Application Note ANCP01. Use a sledgehammer, fire a bullet at it, throw it into a pool....that’s not what we’re talking about. We’re going to show you how to electrically destroy your Arduino, though many of you seem to already know how to do that through unfortunate experience. You know what we mean....that funny smell, the scorch mark on a component, or the dreaded “programmer not in sync” error message -- all signs that you’ve just learned a lesson the hard way. Why are we doing this? If you own an Arduino, it’s good to know what is and what isn’t OK to do with it. We also want you to consider buying our Ruggeduino, which will survive all of the tortures described below.
Configure an I/O pin to be an output then set it high. Here is the path of current flow (the schematic is for the Arduino Uno, which can be found here): Adafruit Learning System. Arduino Tutorials - tronixstuff.