Ok, so AD5204 (the digital potenziometer) is used as voltage divider, with VCC connected to each Ax via 3.3K resistor (measuring 1.74V) and GND connected to each Bx. The voltages on Wx control the current limit for each stepper.
Measuring the voltages after reset:
@W1: 1.74V (Addr: 0, Value: 0xFF, current limit for E0)
@W2: 1.74V (Addr: 1, Value: 0xFF, current limit for E1)
@W3: 0.86V (Addr: 2, Value: 0x80 == DEFAULT, not connected)
@W4: 1.74V (Addr: 3, Value: 0xFF, current limit for Z)
@W5: 0.86V (Addr: 4, Value: 0x80 == DEFAULT, current limit for X)
@W6: 0.86V (Addr: 5, Value: 0x80 == DEFAULT, current limit for Y)
That is definitely not what’s configured in the Firmware.
Furthermore, trying to change the voltages with G-Code commands M907 (*) and M908 did not change the voltage.
So something definitely does not work as it should here…
Can anybody else, please, measure her/his AD5204 and confirm this is a general issue or just an issue with our TAZ?
Any Rambo1.3L Engineers here? The firmware looks correct to my eyes, could this be a hardware bug?
Thanks for any Help!
See https://github.com/ultimachine/RAMBo/blob/master/docs/RAMBoSchem.pdf page 3 for the DigiPot schematic.
(*) in current Lulzbot code M907 is broken for digipot, I added the handling for the X,Y,Z & E codes to make it work, so no, my test works.