I work with a group that’s developing small, inherently unstable air vehicle platforms, and in order to keep development time and costs low, we like to use off the shelf components. The maestro looks like a good fit to offload some processing and pins from our IMU (the CHR-6d works great BTW), but we’re finding that the standard 20ms/50hz r/c PPM rate is just not fast enough to respond to the dynamics. However, many r/c components can accept PPM rates to 400hz. I’m wondering if it would be possible to purchase a customized version of the maestro that allows a minimum 100hz update/PPM rate over UART while still retaining ADC functionality for reporting sensor readings. 200hz would be ideal, and 400 hz fantastic. Another consideration is if the Maestro can interface with 3.3V logic levels. It appears so considering I see a PIC18f14k50 which has an input high of 2V for 5 Vdd.
You can set the update frequency of the Maestro to 100 Hz by adjusting the “Period” parameter on the Channel Settings tab. Please give that a try, and if you are still interested in something customized to be even faster, we should probably discuss it by email. You can mail me directly at paul at pololu dot com. 300Hz will definitely be attainable if you are willing to sacrifice some other features like auto-baud-rate detection; 400 might be possible.
As for 3.3V support, the relevant parameter is the input high level for Schmitt Trigger inputs on that chip. We expect it to work down to just a little below 4.0V. There is a chance your 3.3V signals would just barely work, but I would not want to use it without a level shifter where reliability is a concern.
I gotta say, you guys are awsome. We’ll give 100hz a shot and go from there.
Zach, that is always great to hear. Good luck with your project!