TMC2209 V1.3 VS TMC2208, more of these functions:

1. Blocking rotation detection

Stallguard–TMC2209 provides a load and loss of speed detection technology

2. Current dynamic adjustment

Coolstep–TMC2209 provides a current dynamic regulation technology that saves up to 75% of electrical energy.

– stealthChop2 – for quiet operation and smooth motion

– spreadCycle – highly dynamic motor control chopper

– coolStep – current control for energy savings

– stallGuard4 – sensorless motor load detection

The hardware of the modes UART,DIR/STEP is the same. If you need to use UART mode, just need to modify the firmware.

BIGTREETECH TMC2209 V1.3 UART firmware :

https://github.com/MarlinFirmware/Marlin/pull/14215?fbclid=IwAR1QJDcuRzzhg7TihQcsfGTyx4UPcmtfhqhRw0gCzRL5gfqj5ZMC36wpN5M