A friend has asked me for help with an idea he has which requires a simple RF link to control a 12 volt circuit. One end of the link would need an MCU to collect the inputs and make a decision about the state of the 12 volt circuit. The RF link is used to control the 12 volt circuit. The MCU end would be battery powered and so needs to be low energy. It is only on with a very low duty cycle, less than a dozen times a day for a short while each time. There may be a need for a bidirectional link to verify the serial number of the remote unit, I'm not sure. The range is single digit feet, but there may be metal in the way, similar to a unit under a car hood for example.
I was originally thinking of using Bluetooth, BLE specifically. But I have had some awkwardness with the connection in various uses. One advantage is that qualified modules are available which get around the FCC certification I believe. I found the NRF51822 Eval Kit which seems to be a SOC with both Bluetooth and an ARM CM0, not bad but no certs I would assume.
If the remote unit does not need to be identified, I would think there are much simpler solutions. I expect the type of xmit and receive modules used in weather stations might be adequate.
Any recommendations for units to consider for a prototype?