Hello. A friend of mine and I have a small school project, and could use some help.
One of the goals of the project is to establish a communication of two ATtiny45s such that the tiny with a transmitter on it would send data (lets say number one) constantly and the other tiny with a receiver and a buzzer would signal if the communication stopped for more than 5 seconds.
We bought the cheapest transmitter + receiver (433 MHz) from ebay, and managed to use it with Virtual Wire library on Arduino UNO R3, but the problem occurs with receiver, because to check whether the communication stopped we must use a timer interrupt every five seconds, but VW lib also uses timer interrupt, so we get a conflict somehow.
We also saw on the forum that it is not possible to import VW to tiny (http://forum.arduino.cc/index.php?topic=149928.0, someone made an alternative library that works for ATtiny85). We decided to try to make a small improvised library, that could work for ATtiny45, would only need to send and receive one type of message (just to establish a connection, e.q. constantly sending "a" or something easier) and could easily be made to work well with the simple timer interrupt so we could check the number of received messages every 5 seconds.
Any help would be appreciated. Thank you!
P.S. Because we don't know that much about timer interrupts, we just copy-pasted the interrupt found here: http://www.hobbytronics.co.uk/arduino-timer-interrupts, and managed to make it do interrupts every five seconds.