[Ralph] wasn’t satisfied with the required 5 control pins to drive his nrf24l01+ transceiver module, so he used this circuit needing just 3 pin using an ATtiny85. One of the key components was to ...
The folks at Coretech Robotics put together this project. It does take a little skill to build, but nothing too daunting. They used an SR-HC04 sensor because it's cheap and reasonably precise. An ...