ESC suudenly stopped working after updating px4 parameters

[Tamas Pal 0]

ESC suddenly stopped working after updating px4 pid parameters. I am able to detect esc using ftdi cable; I have also rechecked the voxl2 - ESC UART cable. There is no hardware issue. How to fix it ?

[Alex Kushleyev]

Can you please double check that uart_esc module is enabled and correct baud rate is used (250K default). Do you still have the parameters that you used when ESC was working? Maybe try those.

[Tamas Pal 0]

@Alex-Kushleyev The esc module is enabled but

qshell mixer load /dev/uart_esc quad_x.main.mix

The uart_esc file is missing even after conecting the esc with voxl2. There is no hardware damage. I have checked all the ports many times with multimeter inclding the voltage of RX-TX with respect to ground. All the things are good. I have tested it another voxl2, even tried it with differnt cable. The issue is still there. How to fix the issue?

[Alex Kushleyev]

You should try to use the following commands:

qshell modalai_esc status

also check

qshell param show UART_ESC*

[Anubhav]

Hi @Alex-Kushleyev,

I have tried running the above command:

voxl2:~$ px4-qshell modalai_esc status
INFO  [qshell] Send cmd: 'modalai_esc status'
INFO  [qshell] qshell return value timestamp: 798550454, local time: 798557832

voxl2:/$ px4-qshell param show UART_ESC*
INFO  [qshell] Send cmd: 'param show UART_ESC*'
INFO  [qshell] qshell return value timestamp: 785736853, local time: 785740154

I think voxl2 is not detecting ESC, how can I resolve this?

[modaltb]

Hi @Tamas-Pal-0 ,

Sorry some of the stdout responses don't make it to the shell when evoked with px4-, can you try this section of the developer guide to run PX4 interactively through the shell?

https://docs.modalai.com/voxl-px4-developer-guide/#how-to-access-the-px4-shell-pxh

After that, and you run voxl-px4 manually, you will get a pxh shell, and then the qshell modalai_esc status command should spit out info.

Also, for the param check, no qshell needed, you can use param show UART_ESC* from the pxh shell.

[Alex Kushleyev]

@modaltb , just wanted to double check.. inside pxh shell, the command should be just modalai_esc status (without qshell), right?

[Anubhav]

@Alex-Kushleyev @modaltb

Below is the output of the command qshell modalai_esc status while the ESC was connected and powered on:

INFO  [qshell] Send cmd: 'modalai_esc status'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: modalai_esc status
INFO  [muorb] SLPI: Max update rate: 0 Hz
INFO  [muorb] SLPI: Outputs on: no
INFO  [muorb] SLPI: UART port: 2
INFO  [muorb] SLPI: UART open: yes
INFO  [muorb] SLPI: 
INFO  [muorb] SLPI: Params: UART_ESC_CONFIG: 1
INFO  [muorb] SLPI: Params: UART_ESC_BAUD: 250000
INFO  [muorb] SLPI: Params: UART_ESC_MOTOR1: 3
INFO  [muorb] SLPI: Params: UART_ESC_MOTOR2: 2
INFO  [muorb] SLPI: Params: UART_ESC_MOTOR3: 4
INFO  [muorb] SLPI: Params: UART_ESC_MOTOR4: 1
INFO  [muorb] SLPI: Params: UART_ESC_RPM_MIN: 1000
INFO  [muorb] SLPI: Params: UART_ESC_RPM_MAX: 10500
INFO  [muorb] SLPI: 
INFO  [muorb] SLPI: -- ID: 0
INFO  [muorb] SLPI:    State:           0
INFO  [muorb] SLPI:    Requested:       0 RPM
INFO  [muorb] SLPI:    Measured:        0 RPM
INFO  [muorb] SLPI:    Command Counter: 0
INFO  [muorb] SLPI:    Voltage:         0.000000 VDC
INFO  [muorb] SLPI: 
INFO  [muorb] SLPI: -- ID: 1
INFO  [muorb] SLPI:    State:           0
INFO  [muorb] SLPI:    Requested:       0 RPM
INFO  [muorb] SLPI:    Measured:        0 RPM
INFO  [muorb] SLPI:    Command Counter: 0
INFO  [muorb] SLPI:    Voltage:         0.000000 VDC
INFO  [muorb] SLPI: 
INFO  [muorb] SLPI: -- ID: 2
INFO  [muorb] SLPI:    State:           0
INFO  [muorb] SLPI:    Requested:       0 RPM
INFO  [muorb] SLPI:    Measured:        0 RPM
INFO  [muorb] SLPI:    Command Counter: 0
INFO  [muorb] SLPI:    Voltage:         0.000000 VDC
INFO  [muorb] SLPI: 
INFO  [muorb] SLPI: -- ID: 3
INFO  [muorb] SLPI:    State:           0
INFO  [muorb] SLPI:    Requested:       0 RPM
INFO  [muorb] SLPI:    Measured:        0 RPM
INFO  [muorb] SLPI:    Command Counter: 0
INFO  [muorb] SLPI:    Voltage:         0.000000 VDC
INFO  [muorb] SLPI: 
INFO  [muorb] SLPI: modalai_esc: cycle: 85537 events, 9228157us elapsed, 107.88us avg, min 4us max 440us 9.18
INFO  [muorb] SLPI: modalai_esc: output update interval: 85534 events, 2056.72us avg, min 1249us max 3206224u
INFO  [muorb] SLPI: control latency: 85533 events, 49030648us elapsed, 573.24us avg, min 372us max 925us 62.2
INFO  [muorb] SLPI: Switched to rate_ctrl work queue: 1
INFO  [muorb] SLPI: Mixer loaded: yes
INFO  [muorb] SLPI: Driver instance: 0
INFO  [muorb] SLPI: Channel Configuration:
INFO  [muorb] SLPI: Channel 0: value: 0, failsafe: 0, disarmed: 0, min: 1000, max: 10500
INFO  [muorb] SLPI: Channel 1: value: 0, failsafe: 0, disarmed: 0, min: 1000, max: 10500
INFO  [muorb] SLPI: Channel 2: value: 0, failsafe: 0, disarmed: 0, min: 1000, max: 10500
INFO  [muorb] SLPI: Channel 3: value: 0, failsafe: 0, disarmed: 0, min: 1000, max: 10500
INFO  [muorb] SLPI: Ok executing command: modalai_esc status
INFO  [muorb] SLPI: Sending qshell retval with timestamp 949539937, current timestamp 949539938
INFO  [qshell] qshell return value timestamp: 949539937, local time: 949553192

[Alex Kushleyev]

It seems no data has been received by modal_esc module, but it also seems that the ESCs have not been armed yet. Let's try to query the individual ESC version information:

modalai_esc -i 0 version

and

modalai_esc -i 0 version-ext

(you can replace -i 0 with ESC ID 0..3)

These commands will explicitly send a request to each ESC and get information about its version and should print. version-ext is the extended version information, but basic version command should be sufficient for checking communication.