Hello,
I am evaluating the USB audio example from SDK v14 with an nRF52840-Preview-DK (PCA10056, V0.9.2, 2017.25).
SW9 is set to VDD power, SW6 is set to DEFAULT. The board is connected over both USB connectors to the same computer. The JLink CDC port works well, and I have flashed the precompiled usbd_audio_pca10056.hex
file.
The connection over the native USB port fails most of the time: Windows 7 (x64) then does not recognize the USB device. A few times the connection is OK, and windows installs the driver for the USB audio device and I can set the default playback and recording devices in windows as required for the example.
In the latter case, most of the time only LED1 lights up. In one of -say- 50 trials, I get the first three DK LEDs on, which -as far as I understand- is a good sign. In that case, if I try to play back audio on the USB device, it quickly hard faults (as seen below).
I tried different USB cables, different computers and different (2.0 and 3.0) USB ports, and also recompiling from source. Results are the same.
Is this a Nordic hardware issue? Is there a workaround?
Here's the UART output:
<info> app: Hello USB!
<info> app: USB power detected
<info> app: USB ready
<error> hardfault: Hardfault PC:1288
<info> app: Hello USB!
<info> app: USB power detected
<info> app: USB ready
<error> hardfault: Hardfault PC:128A
<info> app: Hello USB!
<info> app: USB power detected
<info> app: USB ready
<error> hardfault: Hardfault PC:128A
<info> app: Hello USB!
<info> app: USB power detected
<info> app: USB ready
<error> hardfault: Hardfault PC:12AA
<info> app: Hello USB!
<info> app: USB power detected
<info> app: USB ready
<error> hardfault: Hardfault PC:2EB7F550
<info> app: Hello USB!
<info> app: USB power detected
<info> app: USB ready
<error> hardfault: Hardfault PC:128A
Here's the RTT log:
J-Link RTT Viewer V6.16a: Logging started.
LOG: Global terminal added.
LOG: Device "NRF52840_XXAA" selected.
LOG: Found SW-DP with ID 0x2BA01477
LOG: Found SW-DP with ID 0x2BA01477
LOG: Scanning APs, stopping at first AHB-AP found.
LOG: AP[0] IDR: 0x24770011 (AHB-AP)
LOG: AHB-AP ROM: 0xE00FF000 (Base addr. of first ROM table)
LOG: CPUID reg: 0x410FC241. Implementer code: 0x41 (ARM)
LOG: Found Cortex-M4 r0p1, Little endian.
LOG: FPUnit: 6 code (BP) slots and 2 literal slots
LOG: CoreSight components:
LOG: ROMTbl[0] @ E00FF000
LOG: ROMTbl[0][0]: E000E000, CID: B105E00D, PID: 000BB00C SCS
LOG: ROMTbl[0][1]: E0001000, CID: B105E00D, PID: 003BB002 DWT
LOG: ROMTbl[0][2]: E0002000, CID: B105E00D, PID: 002BB003 FPB
LOG: ROMTbl[0][3]: E0000000, CID: B105E00D, PID: 003BB001 ITM
LOG: ROMTbl[0][4]: E0040000, CID: B105900D, PID: 000BB9A1 TPIU
LOG: ROMTbl[0][5]: E0041000, CID: B105900D, PID: 000BB925 ETM
LOG: RTT Viewer connected.
Help and comments are appreciated.
Tamas