TMC262 STEP/DIRECTION SETUP

[STEVE]

I am trying to get my prototype board going. What is the minimum setup info I need to send to the TMC262 to operate in STEP/DIRECTION mode?
The SPI communication is working – I can read back the microstep position in the sine table or the current control scale. As the steps are coming in I can read back the changing microstep positions.
The problem I’m having is it reads open load on both phases: 0110 for bits 4,5,6 and 7. When the driver gets enabled it first reads back 0000 then a short wile later 0100 then with some delay 0110. I did verify all connections from transistor drain to motor wiring on both phases.

[TRINAMIC_BD]

Hello, don't mind the open load bits - perhaps the driver is still disabled. You find a minumum example initialization in the data sheet, chapter 18.

[STEVE]

Loaded: $94557, $D001F, $EF010, $00000 and reading back $07C18.

Before the TMC262 is innitialized Vcc +3.3V and VS +10V is applied, ENN is connected to ground and step pulses are present at 80Hz. At the moment I cannot turn step pulses off 100% - limititation of my present setup. Current consumption is 0.05A on the VS side. Raising VS to 20V maintains current consupmtion at 0.05A
The 4 wires to the stepper motor measure 1.52V DC to ground with a voltmeter . (The scope is measuring the same with a 60 Hz sine wave riding on it)
If ENN is disconnected from ground it reads back $07C60


Regards,


Steve

[TRINAMIC_BD]

Dear Steve,
it looks, like the short to GND flags are active. This will disable the drivers. Please re-check, that you did not mix up BM pins and the bridge control pins.

However, you should be able to readthe microstep counter advancing - please modify EF010 to EF000.

[STEVE]

The VS and VHS pins were interchanged in my schematic (and on the PCB). The resulting symptoms were short to ground fault on both phases and idle current at 0.05A. After I made the proper connections the current dropped down to 0.01A.

The stepper motor is turning now although it sounds like there is sand in the bearings.

Thanks for your help.

Steve

[TRINAMIC_BD]

Hi Steve - the sand in the ball bearings - this could be a GND layout issue - please check sense resistor GND trace rounting - you will find a number of posts on this topic, too...

[STEVE]

I had to put this project on hold back in December. I just fired it up a few days ago but none of the MOSFET gates are driven by the TMC262. I am reading back the internal sine wave table and I see the values changing. Both OLB and OLA flags are set indicating an open load on both phases.
I did connect a storage scope to see the gate driving voltages after power up (and initialization) but there is no activity on any of HA1, HA2, LA1, LA1 or HB1, HB2, LB1, LB2 outputs.
I made 2 more boards and all have the same problem.
Is it possible to blow all 8 outputs on all 3 prototype boards? The first board was running for a few days.

[TRINAMIC_BD]

Hi Steve, I do not think, that you destroyed all gate drivers, this is hardly possible without total failure. I guess, the TMC262 is in disable due to ENN pin not tied low, or TOFF not initialized. Perhaps a TMC262 evaluation board would boost this project? You could have a look at the stepRocker, which is a nice small evaluation board, also.