@Florin Stroiescu in the ar3 upgrade sheet

" The main issue we are dealing with here is that the AR3

uses 5v for the limit switches and returns 5v to the Teensy

– The best way to upgrade to the Teensy 4.1 board is to

run 3.3v out to robot base and then rewire all the limit

switches to the 3.3v."

I also ordered the ar3 motors and placed the order for the encoders and, my questions would be, if im using the ar3 steps for the encoders should I use the steps from the ar4 or continue with the ar3 as I ordered the ar4 complete kit and wiring is different.

will be documenting everything when motors arrive also just in case anyone is in the same steps as I am.

Appreciate the feedback.

@gio s. I am in the same boat, I don't have yet the electrical package. To me, the re-routing of the limit switches to 3.3V was obvious, but thank you for the reference. The issue I am describing, with the encoders running on higher voltage than 3.3V is a bit subtle, and might not bite back immediately, but sending signals (A & B from each encoder) at 5V to the 3.3 inputs of Teensy v4.1 might damage the board in time (and, sometimes, immediately). That's why I will not even try to connect directly the CUI encoders' outputs to Teensy, but just through a level shifting circuit, like in below image (that has to be repeated for each of the encoders' outputs, 12 in total, two 74LS07 ICs will suffice):

Please pay attention, the buffer used here as level shifter has to be open-collector, or open-drain. Other types of level shifters are available, but this would be one of the cheapest and most available. I will post the whole schematics and assembly when I will have it ready. Doing this, still needs adaptation for the limit switches, either supply them from 3.3V (the simplest and cheapest way), or add another level shifter for each limit switch.

Regarding the steps to follow, you need to understand exactly what each steps means, Chris was very careful to describe everything in detail, but when combining the AR3 kit with the AR4 controller (aka Teensy), things might become a bit hairy if you don't know what you are doing. I might return the favor that Chris done to all of us, and create the step-by-step instructions on how to setup the combined setup (AR3 electrical with Teensy 4.1) - but this will take some time, unfortunately.

@Florin Stroiescu followed, will gladly be looking forward to your build and I will follow steps for the ar3 (3d printed) and save the aluminum pieces for the ar4 when the motors are available, save me the trouble of doing extra work but greatly appreciate the advice.