ESP32 UART-USB Brige How to use

[stefan.erni]

Hi Martin

My testprogram:

Adafruit_5691_01_fc11_19.fcfx

(66.15 KiB) Downloaded 51 times

You can find a description of the hardware here
viewtopic.php?t=3644

[stefan.erni]

Hi Martin

One a question:
There is still one entry missing :

CONFIG_USB_DEVICE_ENABLED=y
CONFIG_TINYUSB_ENABLED=y
CONFIG_TINYUSB_DEVICE_ENABLED=y
CONFIG_TINYUSB_CDC_ENABLED=y

in the file:

sdkconfig.defaults.esp32s3

But in FC11 there are so many sdkconfig.defaults.esp32s3.
Which one is the right one?

[stefan.erni]

Hi Martin

I've now updated to 5.3.1 and added the USB Tiny dependency.

I also have some C code there can I use it in Flowcode?

include are ok:

Code: Select all

#include "tinyusb.h"
#include "tusb_cdc_acm.h"
#include "esp_log.h"

2026-03-30_11-36-59.PNG (39.99 KiB) Viewed 244 times

C-Code for USB:

Code: Select all

void app_main(void)
{
    // TinyUSB Basisconfig
    tinyusb_config_t tusb_cfg = {
        .device_descriptor = NULL,  
        .string_descriptor = NULL,  
        .external_phy = false       // intern USB-PHY des ESP32-S3
    };

    // USB-Device (TinyUSB) start
    tinyusb_driver_install(&tusb_cfg);

    // USB-CDC (virtueller COM-Port) config
    tinyusb_cdcacm_config_t cdc_cfg = {
        .usb_dev = TINYUSB_USBDEV_0,
        .cdc_port = TINYUSB_CDC_ACM_0,
        .rx_unread_size = 64,
    };

    tusb_cdc_acm_init(&cdc_cfg);

    // wait, for USB clean
    vTaskDelay(pdMS_TO_TICKS(300));

    // „Hello world“ send
    const char *msg = "Hello world\r\n";
    tusb_cdc_acm_write(TINYUSB_CDC_ACM_0, (uint8_t *)msg, strlen(msg));
    tusb_cdc_acm_write_flush(TINYUSB_CDC_ACM_0, 0);

    //  (Flowcode need main loop)
    while (1)
    {
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

[mnfisher]

Hi Stefan,

Yes - you can use the C to initialise - rename (app_main) initialise (or some such) and add a function definition to the 'includes' (top) box of supplementary code... ( void initialise(void); ) Remove the loop (and the 'hello world'?) from the end of the function...

Then call initialise(); from a C block.

You can also add a 'Print(char *str);' function - which could call tusb_cdc_acm_write and flush..

Martin

[stefan.erni]

Hi Martin

Thank you Martin I'll give that a try.

I've had a bit of success with `print_F` so far.
I still have no idea how to send an array

Very short program:

Post_esp531_1.fcfx

(9.77 KiB) Downloaded 47 times

C-Code:

2026-03-30_13-51-31.PNG (15.24 KiB) Viewed 231 times

On computer (regardless of the baud rate)

2026-03-30_13-51-07.PNG (112.9 KiB) Viewed 231 times

[stefan.erni]

Hi Martin

Your suggestion works perfectly!

I had to make a few adjustments. Sending is done using the function in the additional code. How can I send an array from my program? I'm not sure exactly where I need to add FCV_.

Post_esp531_3.fcfx

(13.91 KiB) Downloaded 30 times

2026-04-01_12-04-06.PNG (92.72 KiB) Viewed 140 times

SNAG-0075.PNG (168.88 KiB) Viewed 140 times

[mnfisher]

Hi Stefan,

Something like this?

Post_esp531_3.fcfx

(12.4 KiB) Downloaded 28 times

However - I have some serious issues recompiling this (- a nested #include somewhere!) - I removed the UART component thinking it was this (and I had a seemingly unending circular list of errors!) - but I still get "
from C:\Users\Martin\Downloads\tinyusb.h:66,
from C:\Users\Martin\Downloads\tinyusb.h:66,
from C:\Users\Martin\Downloads\tinyusb.h:66,
from C:\Users\Martin\Downloads\tinyusb.h:66,
from C:\Users\Martin\Downloads\tinyusb.h:66"

A couple of hundred times

However - if you can get it to compile - it should work.... I added a 'Print' macro to allow output to be made a little more 'flowcode'

Will have to fiddle a bit and find out what's gone wrong with my setup

Martin

[mnfisher]

I commented out a couple of the #includes in supplementary code - you'll probably need to re-enable....

[stefan.erni]

Hi Martin

Your program is working fine

2026-04-01_13-09-13.PNG (17.48 KiB) Viewed 131 times

Maybe You need ESP-IDF 5.3.1

and in the menuconfig batch file
this line ....

Code: Select all

python "C:\Users\Kfs-Forschung\Desktop\esp-idf-2\tools\idf.py" add-dependency esp_tinyusb

[stefan.erni]

Hi Martin

I expanded your example to include an array for sending data, and it works.
I can also receive the binary data array very easily using the Flowcode APP Developer.

Demo:

Post_esp531_4.fcfx

(13.77 KiB) Downloaded 28 times

2026-04-01_14-44-56.PNG (148.21 KiB) Viewed 114 times