Requesting additional brain power from smart people

[Jeffrey Schwartz]

I've been playing with the Raspberry Pi single board computer. 

Neat toy - I got a Pi Zero W that I'm using for a robotics project

Anyway, ran across this site : 

https://github.com/ha7ilm/qtcsdr

Which looked like a neat application... there's a number of articles on using the PWM on Pin 18 as a radio transmitter, and plugging in a USB radio dongle to do reception. 

Reading that got me thinking.  I'm fiddling with robotics, and this idea popped into my head of having my Droid be able to do some limited Ham things. 

If I were to come up with a 2 meter filter for transmitting, I could get info back from the robot via my HT, which would be pretty neat. 

But there's limited USB availability when you're stuffing things into a robot body, so is there an easier way than a USB dongle? 

Which lead me to http://www.qrz.lt/ly1gp/SDR/ 

What I'd like to do, and my radio design skills aren't quite up to, is replace the VFO part of the circuit with the input from another PWM on the Pi, then run the incoming audio through some kind of filter and into an analog input pin on an Arduino

I'd kinda like to be able to do some APRS off this, plus a couple simplex freqs. 

Any ideas? thoughts? Advice? 

[Brian Bartholomew]

http://www.rowetel.com ended work on the SM2000 (not SM1000) VHF SDR
transmitter project because getting the output clean was harder then
they thought. Can you do better than them?

If you just want the functional result, consider a Pi with WiFi.

Brian