CDC-ACM Usb Host on ESP32-S3

[mayo2ca]

Hello,

I'm trying to run a USB Host and collect data from a device that exposes itself as a generic CDC-ACM device. I'm trying to run the usb/cdc_acm_host example and running into a crash I can't quite track down.

First, I was running into an issue with the usb_host_cdc_acm component, as it does not recognize devices with class and subclass set to 0x00. I modified the component (specifically this line https://github.com/espressif/idf-extra- ... ost.c#L674) to look for class and subclass 0x00. The rest of the code works as expected, as it looks for a interface with the appropriate class and subclass.

Next, I run the cdc_acm_host example, modifying it to look for the correct vendor and product IDs, as well as adapting the line coding to my device (115200, 8 data bits, 0 parity, 0 stop bits).

The example runs and receives some data from the device, but will periodically (30 seconds or so) reboot. Here's a sample output just before the panic and reboot:

Code: Select all

I (1424) USB-CDC: 0x3fc9d858   63 74 69 6f 6e 53 74 61  74 75 73 3e 0d 0a        |ctionStatus>..|
I (1434) USB-CDC: Setting up line coding
E (1444) USBH: usb_transfer_t num_bytes > data_buffer_size
E (1444) cdc_acm: cdc_acm_host_send_custom_request(1294): CTRL transfer failed
E (1454) cdc_acm: cdc_acm_host_line_coding_get(1221): 
ESP_ERROR_CHECK failed: esp_err_t 0x102 (ESP_ERR_INVALID_ARG) at 0x420091f8
0x420091f8: app_main at ../reader/cdc_acm_host/main/usb_cdc_example_main.c:157 (discriminator 1)

file: "./main/usb_cdc_example_main.c" line 157
func: app_main
expression: cdc_acm_host_line_coding_get(cdc_dev, &line_coding)

abort() was called at PC 0x40379c2b on core 0
0x40379c2b: _esp_error_check_failed at ../reader/esp-idf/components/esp_system/esp_err.c:50



Backtrace: 0x40375976:0x3fc99170 0x40379c35:0x3fc99190 0x4037ff82:0x3fc991b0 0x40379c2b:0x3fc99220 0x420091f8:0x3fc99250 0x42024a27:0x3fc992b0 0x4037c56d:0x3fc992e0
0x40375976: panic_abort at ../reader/esp-idf/components/esp_system/panic.c:452

0x40379c35: esp_system_abort at ../reader/esp-idf/components/esp_system/port/esp_system_chip.c:93

0x4037ff82: abort at ../reader/esp-idf/components/newlib/abort.c:38

0x40379c2b: _esp_error_check_failed at ../reader/esp-idf/components/esp_system/esp_err.c:50

0x420091f8: app_main at ../reader/cdc_acm_host/main/usb_cdc_example_main.c:157 (discriminator 1)

0x42024a27: main_task at ../reader/esp-idf/components/freertos/app_startup.c:217 (discriminator 13)

0x4037c56d: vPortTaskWrapper at ../reader/esp-idf/components/freertos/FreeRTOS-Kernel/portable/xtensa/port.c:162

Line 157 of the example usb_cdc_example_main.c (https://github.com/espressif/esp-idf/bl ... ain.c#L157) is trying to read the line coding.

I've further experimented with the code and tried to remove the

Code: Select all

cdc_acm_host_line_coding_get

call (I don't need to read it), and stick with only setting it (original line 165), but in that case, the error is the same, just moved to the line with

Code: Select all

 cdc_acm_host_line_coding_set

.

Experimenting even further, I modified the code such that the line coding is only set when the device is opened, rather than on each loop, but this results in similar issue.

I have entertained the VCP route, but I can't find much on the device I have, so I would be essentially implementing a generic CDC ACM driver, which already exists in the usb_host_cdc_acm component.

Does anyone have suggestions on further debugging?

Thanks!