Easy DIY Telemetry Goes the Distance

[Paweł Spychalski] wrote in to tell us about some experiments he’s been doing, using cheap 433 MHz HC-12 radio units as a telemetry radio for his quadcopter.

In this blog post, he goes over the simple AT command set, and some of the limitations of the HC-12 part. Then he takes it out for a spin on his quadcopter, and finds out that his setup is good for 450 meters in an open field. Finally, he ties the radio into his quad’s telemetry system and tethers the other end to his cellphone through a Bluetooth unit for a sweet end-to-end system that only set him back around $20 and works as far out as 700 meters.

The secrets to [Paweł]’s success seem to be some hand-made antennas and keeping the baud rate down to a reasonable 9600 baud. We wonder if there’s room (or reason?) for improvement using a directional antenna on the ground. What say you, Hackaday Antenna Jockeys?

Also check out this very similar build where an ESP8266 replaces the Bluetooth module. And stashes it all inside a nice wooden box! Nice work all around.

ez430 home automation

[Oliver] has been doing some work to use his TI ez430 Chronos wristwatch for some home automation. He’s working with a RF controllable lightbulb adapter which operates in the 433 MHz band. A dirt-cheap breadboard-friendly transmitter is available from Seeed Studios and he uses this in conjunction with a computer and an Arduino. Before the trolls get to their thing, YES, this is incredible overkill. But remember that he’s prototyping. We hope that if he intends to actually use this setup he’ll migrate to something like an ATtiny2313 running V-USB. Better yet, you should be able to tap into the watch’s companion receiver and cut the computer out completely.

If you’re easily amused you’ll appreciate the video of a light turning on and off after the break. If you’re a little harder to please then take a look at Oliver’s methods of using Python processing for the watch’s data.

Ok, now we’ve seen this watch turning on lights and unlocking doors. What else ‘ya got?