Hi @carlos.silva, thanks for the instructions. I changed the FW to automatically start the responder app with my parameters, and disabled the UART communication by removing the define USB_ENABLE from the project preprocessor settings. However, that didn’t fix the FiRa ranging problem.
It seems that the issues is related to the USB driver but independent from the UART communication.
I flashed the original CLI FW to prevent any side effects of my changes. I can also rule out any power supply issues because I get the same results with a laboratory power supply and batteries.
This is what I found out:
The FiRa ranging works as expected as soon as the green LED D9 on the responder board goes ON.
This happens in the function “usbd_user_ev_handler(…)” in “\Src\HAL\Src\nrfx\HAL_usb.c”
static void usbd_user_ev_handler(app_usbd_event_type_t event)
{
switch (event)
{
case APP_USBD_EVT_DRV_SUSPEND:
bsp_board_led_off(LED_USB_RESUME);
break;
case APP_USBD_EVT_DRV_RESUME:
bsp_board_led_on(LED_USB_RESUME);
break;
case APP_USBD_EVT_STARTED:
break;
case APP_USBD_EVT_STOPPED:
app_usbd_disable();
bsp_board_leds_off();
break;
case APP_USBD_EVT_POWER_DETECTED:
if (!nrf_drv_usbd_is_enabled())
{
app_usbd_enable();
}
break;
case APP_USBD_EVT_POWER_REMOVED:
app_usbd_stop();
break;
case APP_USBD_EVT_POWER_READY:
app_usbd_start();
UsbSetState(USB_CONFIGURED);
break;
default:
break;
}
}
- “case APP_USBD_EVT_DRV_RESUME:”
- bsp_board_led_on(LED_USB_RESUME);
To me it seems that the USB driver has to reach a certain state before the responder app can work properly.
The state can be reached in a reproducible manner as described in the picture below.
In order to get the green LED D9 ON, there MUST be a micro USB connector plugged into J20. Only providing VBUS via the test point pad TP14 does NOT work. So it seems to me that the plug detection is involved.
At this point I’m stuck. I want to start the responder board by just connecting the power supply. I have no idea about how to solve the USBD issue.
BR,
christian
