A python package to read/write to registers to TMC motion controllers via the uart. This package includes register addresses for the TMC5160 as specified here:
https://www.trinamic.com/fileadmin/assets/Products/ICs_Documents/TMC5160A_Datasheet_Rev1.14.pdf
Other TMC controllers could be adapted by providing the register include file with its specific register addresses.
There are some test scripts in the ./bin directory. Tested on both Windows and Raspberry PI with a USB/RS485 adapter to a custom board with a TMC5160 chip with uart pins broken out.
There are two read functions. read_int() and read_reg(). The first returns a 32 bit value and second returns a 4 byte object.
Repository can be found:
https://github.com/troxel/TMC_UART
from tmc_uart import TMC5160_UART
from tmc_uart import tmc5160_reg as reg
drvconf = { 'comm_dev':'/dev/ttyUSB0', 'baud':500000 }
drv = TMC5160_UART(drvconf)
mtr_id = 0
ifcnt0 = drv.read_int(0, reg.IFCNT)
drv.write_reg(mtr_id,reg.GCONF,0x0000000C)
ifcnt1 = drv.read_int(0, reg.IFCNT) # Number of successful uart writes
print("IFCNT before and after: {} {}".format(ifcnt0,ifcnt1))
gconf = drv.read_reg(mtr_id, reg.GCONF)
print("GONF = ",gconf)
xactual = drv.read_int(mtr_id,reg.XACTUAL)
print("XACTUAL = ",xactual)In read_reg and write_reg there is a sleep function call that should be tuned to your specific hardware and baud rate. Set up a loop with repeated read or write calls and decrease sleep time until you start missing transactions. I was able to get 500000k baud without problem. You can go higher but would need to supply an external clock to the chip.
I used a regular RS485/USB adapter to communicate using differential signals. Trinamic has indicated that the interface is only designed for 3.3 volts. I measured the device I was using and it was around 4 volts peak-to-peak, no problems as of yet after hundreds of hours of operation.
I am using a custom board with multiple TMC5160 designed by