I am thinking of making my own UHF tracking transmitters for a wildlife study.
Could I just connect a low power microcontroller to the Vcc part of this circuit
http://www.instructables.com/id/Tiny-UHF-Tracker-Transmitter/
(e.g. Attiny85) and program it to turn the transmitter on after 10 days for a couple of hours every afternoon only (i.e. during the time when I'm searching for the transmitters)?
Or are there other considerations I haven't thought of here. I'm very unfamiliar with radio. If someone has other suggestions on how to significantly increase the battery life that would also be useful. I need to keep everything less than 2g (lighter is better).
My plan is to also have a temperature sensor and store temperature data on the Attiny. The main purpose I have for the transmitters would be to find the animals at the end of the study to retrieve the sensors rather than to track the animals so it would not need to be working continuously.
Possibly this is an obvious question and it would work fine, but it will be a lot of work so just wanted other opinions in case someone can see that it won't work or can suggest a simple and better way to increase the battery life.
Really appreciate any help, thanks!!
Best Answer
Yes - a microcontroller will allow you to save much energy and give you fine control over the whole operation.
You could get much improved range (or energy efficiency) if the radio used better modulation than OOK, for example LoRA (RFM95).
You did not say the exact range you need. There are some really tiny modules that contain everything (MCU + radio + antenna). Examples: SP1ML, BL-652.
The main challenge I see is the battery. A CR2032 battery weight 3 grams alone.