Low-cost Talon SRX computer?

[ozrien]

Hey All, Some answers below...

Does anyone have an inexpensive (<$100, or at least < $200) way (both hardware and software) to control a Talon SRX (in encoder mode) which includes both driving at a specified speed and driving (a single encoder) to a "click count"?

We get this question a lot through our support email. This is one of the main reasons why we made the HERO development board.
http://www.ctr-electronics.com/hro.html
It's a C# based NETMF board that allows you to write/debug C# robot code (works with the free Visual Studio IDE/Debugger). This is where we add features to our CAN actuators first, test them, then port what makes sense to the FRC system.

Our C# library is open source so you can use it as a reference for porting the Talon library to whatever.
https://github.com/CrossTheRoadElec/HERO-SDK

Also, if you are married to another hardware platform (familiarly, preference, whatever) you should consider looking at HERO anyway as a tool to field-upgrade/set-IDs, and to get your robot moving immediately. Then you can begin your porting effort by studying our library.

If you happen to be at Worlds this week, check out our demos at our booth. We'll have at least one robot using HERO and Talons.

Not that I really want to, but is there an inexpensive C# programming environment?

Visual Studio Community is free, see HERO User's Guide for installation steps.

...be wary of the security token put in the CAN bus every 100 msec (I believe that's still a thing). ....

We have FRC and nonFRC firmware. FRC firmware requires a roboRIO that safely tells us that we can enable, nonFRC does not need the roboRIO to enable.
The firmware file is on our site, use a HERO or roboRIO to field-upgrade your Talons.

A search for CAN bus shields turned up a number of shields

I've had a few customers do this. Typically they prove out what they want to do using HERO, then do a minimal port to Arduino/RaspPi/whatever. This is particularly helpful if you don't have a lot of flash on your platform.

I've also had a few customers just send high level commands to a HERO, which in turn updates the Talons (over UART or similar). See HERO User's Manual for serial example.