NRF52840 Dongle USB Power only works with debugger connected

RE: NRF52840 Dongle USB Power only works with debugger connected

mtsunstrum — Sun, 21 Feb 2021 05:18:42 GMT

Seems like something may have damaged the PCA10059 ... just not sure what.

From my 2nd new PC10059, I dumped complete flash contents, including UICR register

(nrfjprog --readuicr --readcode xxx).hex

Then I reprogrammed that into the PCA10059 where VDD_OUT is not working. Did a readback to verify code/UICR are presumably identical.

With both running same code/UICR it did not address the problem with the one PCA10059. :{

RE: NRF52840 Dongle USB Power only works with debugger connected

mtsunstrum — Sun, 21 Feb 2021 04:26:33 GMT

Saw the exact same thing today. New PCA10059 (Version 1.2.0)

Occurred after I successfully flashed in an application (which happened to blow away the existing USB DFU Bootloader). Application ran fine.

The issue where VUSB was healthy, but VDD remained stuck at 0.45V seemed to occur after attempting a new JTAG flash attempt.

Stroke VDD_OUT momentarily with a 3V3 voltage, and voila it them remains at presumably its REGOUT programmed value of 3.0V.

Remove from USB port, and problem occurs again. Stroke VDD_OUT with 3V3, and it comes alive. So weird.

Gives me a feeling there is some power up sequence that is not happening properly.

On the faulty unit, I also noticed that DECUSB/C20 is measuring 0V ... on normal unit, this is 3.3V. So gives a sense that something is preventing nRF52840 USB from enabling it's internal 3V3 USB supply.

RE: NRF52840 Dongle USB Power only works with debugger connected

haakonsh — Tue, 15 Oct 2019 11:39:04 GMT

Is SB1 open and SB2 shorted?

What is the voltage on the VBUS pin and VDDH in the failing scenario?

What voltage have you configured REG0 to output?

RE: NRF52840 Dongle USB Power only works with debugger connected

bersaden — Fri, 11 Oct 2019 09:51:00 GMT

I have compiled and tested the usbd, usbd_cdc_acm, usbd_hid_generic, usb_msc, usbd_hid_composite, usbd_ble_uart, ble_app_hrs, and blinky examples for both PCA10056 and PCA10059, with identical behaviour observed. In the case of blinky, I made sure to set the correct LED pin.

The voltage of VDD after plugging into USB is 0.45V and nothing happens. After I use the debugger as described, VDD is 1.8V, or whatever I've defined for REGOUT0 (have also tested with 3.3V and it works) and the device comes to life and enumerates over USB, starts blinking, or starts advertising over BLE.

After removing the debugger, VDD stays at 1.8V (or REGOUT0 value) and the device continues to operate on USB power.

I have found an identical issue reported here with the official pca10059 dongle, so I'm inclined to believe that something has broken in the regulator stages of the SOC.

RE: NRF52840 Dongle USB Power only works with debugger connected

haakonsh — Fri, 11 Oct 2019 08:27:40 GMT

[quote user="bersaden"]I'm just using the standard pca10056/pca10059 examples in SDK 15.3.0[/quote]

I need to know exactly what example you're running and for what target.

The module schematic seems to be correct.

[quote user="bersaden"]Again, the dongle does not power up until I provide power to VDD or toggle the debug lines with a 3.3V signal. [/quote]

What is the voltage of VDD before and after you do this?

RE: NRF52840 Dongle USB Power only works with debugger connected

bersaden — Wed, 09 Oct 2019 14:19:26 GMT

Thank you for your response. I'm just using the standard pca10056/pca10059 examples in SDK 15.3.0 trying to get something to work, so I'm not sure why it wouldn't be working.

Reading the USB CDC ACM documentation, it seems like the debugger is required, so I tested everything again with the ble_app_hrs examle for pca10059. Again, the dongle does not power up until I provide power to VDD or toggle the debug lines with a 3.3V signal. After doing this, the dongle starts advertising and I'm able to unplug the programmer and it keeps working off USB power. Perhaps the board from the schematic above is different enough that I need to define a custom board.h file, but I'm not sure how I'd go about that for this dongle. Could the way DCCH is connected to VDDH/VBUS have something to do with this problem?

RE: NRF52840 Dongle USB Power only works with debugger connected

haakonsh — Wed, 09 Oct 2019 13:02:14 GMT

My best guess is that somewhere in your application you're trying to put the system into SystemOFF at a point where you'd rather want to use SystemON Idle, and the SDK is set up to use Emulated System OFF mode whenever the debugger is attached.

I'd double-check how your application puts the device into sleep, as it fits perfectly with the symptoms.