Single-chip radios for "garage-door opener" applications.

This page gives resources for using a transmitter chip and receiever chip on fabbed boards for one-way communication. These chips are not as fast or versatile or long-range as the nrf24L01 modules, but they can be much simpler to use. They are devices used for applications like garage-door openers, or other short range low data rate purposes.

These chips all require an external clock, usually a crystal. It is also possible to use an external clock reference, such as the PWM output from a tiny AVR chip. For the transmitter chip described on this page, the clock can be a 10MHz PWM signal derived from an AVR with 20 MHz crystal, leading to transmission at 32 times that frequency, 320 MHz. The receiver clock is another AVR chip PWM at 5.00 MHz.

Note that both of these chips are on the way to obsolescence! I will have a few of these chips in the inventory at Harvard. If you would like to explore this solution, please contact me for chips and more details. (Rob Hart, It is time to look for another cheap and simple solution (like the MICRF112/113 and MICRF220) or to move to the NRF24L01 for this type of application.