I have the Vex starter kit but not the programming module because the local stores were out. I started to look into creating my own hookup, thinking that the system was fairly open. I think my assumption may be partially off.
I ran across this FAQ: https://vexforum.com/t/programming-module-protocol/12267/1
It references Microchip AN851. What’s not clear from the FAQ not is whether or not the current implementation follows that spec. I’m guessing it does not, not to the “T.”
What I want to ask is if Vex plans to open the system up more (i.e., provide schematics so folks can create their own hookups to program the controller, or specs on using Vex’s variant of the programming protocol, assuming its different than what AN851 outlines)?
I bought the kit because I read into (possibly incorrectly so) the IEEE Spectrum’s write-up that Vex utilized using standard controllers and was open for advanced users. Yes, I can see it obviously is using a very standard PIC, but it appears from the above mentioned FAQ item that Vex wants to keep things somewhat hidden/closed. If so, this is a little bit of a bummer for me.
My goal was to get a kit, yes, but also something that kept me as close to the real processor as possible (not just in writing code but in accessing / programming it at its lowest level… well if only the serial iface is reasonably available, I would want that to be open, not layered with proprietary hidden stuff).
Yes, one can hack away, but I was hoping for something fully open as a kit.
My vote (if it helps with any long term plans) is to see a good kit that is pretty much in a developer’s direct use and control of the processor in all reasonable manner of speaking. My guess is there’s are kits already out there, or one can start with a Microchip processor dev kit… perhaps that’s the way to go. Yes, that’s what I mean: a kit that’s like getting a Microchip dev kit but with all the other Vex stuff. No hidden protocols or nonsense like that.
Can Vex or anyone comment on any of this? Does what I want exist with Vex and am I misreading, or is it somewhat proprietary as it seems to be?
Our protocol is proprietary and we can not release any other information about it. Vex was designed so that even students can use the system and program it; in doing so, we try to prevent certain things from happening which can prevent other things from functioning. The average user will not get involved with communicating directly with the micro-processors at a low level and will need for most things to be taken care of. You should start with a Microchip development kit as you suggested which you can then build upon, virtually creating your own Vex system.