I’m working on an embedded software-defined radio for sending PSK31 telemetry data that can run in the BeagleBone Black PRU (or perhaps repurposing the LCD interface) as well as smaller devices like the Teensy 3.1 with an embedded Digital-to-analog converter. Preliminary source is available from github….
BeagleBone Black PRU
Using a BeagleBone Black instead of the teensy opens up more useful spectrum. The DAC on the Teensy is limited to mostly audio frequency ranges, but the PRU can easily generate a smooth 2.5 MHz carrier. A simple R2R DAC isn’t the cleanest , but generates acceptable signal that was capable of being received a few meters from the IC-7000 without any amplifier.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.