pmantoine
commented
2 weeks ago You are correct that the revB documentation has not been updated. However you are not correct re the topside regulator to VIN pads.
The VIN connection on the top side of the board from the 7.2V switching regulator to the VIN pin down to the Arduino has always been connected by default, and remains so across all revisions. The trace joining them is now revealed as we removed the solder mask to make it easier to see and cut if necessary.
The VM to VIN pin on the bottom always defaults to disconnected, naturally.
The regulator disable sense has changed because we were forced to alter the circuit to include a switching voltage regulator from another vendor (TI in this case) due to unavailability of the part used in revA. The TI regulator has the opposite sense to its enable pin. The silk screen is corect that you need to solder the pads to DISABLE the regulator in revB vs cut the pad as you once had to for revA.
The schematic (motor-shield.pdf) included in the repository is correct.
We have been remiss in not fixing the Readme.md documentation to match, apologies. It will be done as we revise documentation in preparation for the v5.4.0 release of DCC-EX. Note also that the links to the repository from the main DCC-EX page are also incorrect. Correct link is: https://github.com/DCC-EX/EX-MotorShield8874
Sent by Eugene Wolski (ejwolski@icloud.com). Created by fire.
Hi!
I recently received the Rev B board, and I noted that the documentation on GitHub shows only the Rev A board. Specifically, the PCB jumpers appear to have been changed for VIN and Regulator to VIN - they appear to be opposite from Rev A board. For example, disabling VIN on Rev A requires cutting the trace, while VIN appears disconnected by default on Rev B. For the Regulator to VIN, the PCB jumper changed from ENABLE in Rev A to DISABLE in Rev B.
Do you have updated documentation available for Rev B? If not, can you at least confirm the changes/differences I mentioned?
Cheers!
Gene Wolski