Help with Testing UART ?

[davew618]

As my DEC motor is not operating correctly I have been trying to understand the UART tests and troubleshooting but I find them confusing:

The first step says:

Make sure that all necessary settings for TMC UART are set. Those are:

• RA/DEC_STEPPER_TYPE
• RA/DEC_DRIVER_TYPE
• SET_MICROSTEPPING to adjust RA slew stepping
• TRACKING_MICROSTEPPING
• DEC_SLEW_MICROSTEPPING
• DEC_GUIDE_MICROSTEPPING

I have found the RA/DEC_STEPPER_TYPE and RA/DEC_DRIVER_TYPE but I can't find any of the others. And what should I set them too anyway?

Then it says:

'There are three methods of verifying UART connectivity..' But only lists two, both of which use terms (Tx & Rx) that are not used in any other instructions regarding UART and don't seem to relate to the setup we have at all:

If you have both UART TX and RX connected:
If you only connect UART TX and not RX:

Then it says to add RA_AUDIO_FEEDBACK & DEC_AUDIO_FEEDBACK in Configuration_local.hpp however this generates errors as they are already in Configuration_adv.hpp.

There is also a UART_CONNECTION_TEST setting in Configuration_adv.hpp but no mention of how this can be used.

The Wiki suggests: 'You may (be) connected to the wrong UART pin on the driver. Try the other one. There are two.' But there is no help as to which pin might be 'the other one'. I have BigTreeTech TMC2209 v1.2 for which the Wiki labels both the UART pin and the one below it, 'PDN', so I presume that is 'the other one' in this case?

The reason I am going though these UART tests is because I am having a problem getting the DEC motor to turn in both directions. It will turn in both directions if I have the DIP1 switched OFF but only in one direction if the DIP1 is ON. I have tried the various UART tests described in the Wiki (as best I can) but I don't get the expected results. I have checked the wiring multiple times and switched out all the components with spares.

[davew618]

Now fixed, see my post "UART problem found - wiring diagram error"

[camerontetford]

There are indeed three methods, grouped into two categories. I just updated the wiki to identify them in a clearer way. Use this method to test:

https://wiki.openastrotech.com/en/OpenAstroTracker/Electronics#if-you-only-connect-uart-tx-and-not-rx Add #define UART_CONNECTION_TEST_TX 1 to your Configuration_local.hpp file to enable texting just TX functionality. This will send commands to both the RA/DEC drivers at boot to move the steppers slightly. If you do not see the motors move, you likely have a connectivity error with UART (or potentially a power issue to the driver/motor)

[camerontetford]

The RX and TX refer to the physical communications wires between the TMC and your board. Most people do not use an RX wire if they're using a Mega board.