Softdevice example doesn't start when powered by other source than MCU interface.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Tue, 17 Oct 2017 13:21:04 GMT

yes it solve it.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Bjørn Kvaale — Tue, 17 Oct 2017 13:18:45 GMT

Interesting! So did this solve your problem then?

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Tue, 17 Oct 2017 13:04:18 GMT

If I define other pins on nRF52840 to drive Uart signal (TxD, RxD), which are not link to the Analog Switch FSA2466, it works with all power supply configuration.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Fri, 13 Oct 2017 14:52:16 GMT

When I powered the board by the connector J2 (interface MCU) the SW (debug) signal is routed between the PCA10056 and the nRF52840 through the Analog Switch FSA2466 if I powered the board with another connector, this signal is cut off. Perhaps this can help us.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Fri, 13 Oct 2017 14:29:45 GMT

I looked at the signal of the LF CLK source and it is a correct signal at 32.8kHz with 200mV peak to peak.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

endnode — Fri, 13 Oct 2017 12:47:32 GMT

Well that should be independent on the power source. The only HW thing i relays on is LF CLK source. If you have logical analyzer or oscilloscope you can try to see what LF crystal on the board is doing...

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Fri, 13 Oct 2017 12:09:11 GMT

After investigation, it seems that this call of function "ret_code = sd_softdevice_enable(&clock_lf_cfg, app_error_fault_handler);" reset the processor when the board is connected with J3 (nRF USB).

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Fri, 13 Oct 2017 09:18:20 GMT

I have try with a lithium coin cell but it doesn't work too. I also try to move SW9 to USB but it doesn't work too. If you see the schematic of the nRF52840-Preview-DK and you select VDD to nRF power source you can see that the power supply is the same across the board when powered by J3 or J2 the only difference is USB detection is not done by the PCA10056 if you powered by J3 (nRF USB).

RE: Softdevice example doesn't start when powered by other source than MCU interface.

endnode — Fri, 13 Oct 2017 09:07:14 GMT

Nice. If you want to power the target from USB then you need to move SW9 to USB, at least this is how I read nRF52840 PDK user manual... definitely worth trying to use other means like external VDD to VIN PIN of P20 or battery and see if then BLE works on the target. If so then you just have wrong setting of SW9 and 10 while powering through USB (or other problem like bad cable).

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Fri, 13 Oct 2017 08:51:34 GMT

For example, I connect the demo board with a USB cable to the MCU Interface (J2), I copy this hex file "nRF5_SDK_14.0.0_3bcc1f7/examples/peripheral/blinky/hex/blinky_pca10056.hex" to the removable file named JLINK and now I see the 4 led blinking. Now I disconect, the USB cable, I don't move the nRF power source selector (SW9) VDD is still selected and I connect the usb cable to the nRF USB connector to power the board and I can see the led blinking.

Now I reconnect the demo board with a USB cable to the MCU Interface (J2) , I copy this hex file "nRF5_SDK_14.0.0_3bcc1f7/examples/ble_peripheral/ble_app_uart/hex/ble_app_uart_pca10056_s140.hex" to the removable file named JLINK and now I see the led 1 blinking, and I can see "Nordic_UART" device if I scan BLE devices. Now I disconect, the USB cable, I don't move the nRF power source selector (SW9) VDD is still selected and I connect the usb cable to the nRF USB connector to power the board and the four leds are switch on with few luminosity and if I scan BLE device I didn't found the Nordic_UART device.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

endnode — Fri, 13 Oct 2017 07:11:31 GMT

OK. So at least nRF52840 is alive, that is good. Now what exactly is the difference between working and not working examples? How you flash it to the board (when you have SEGGER J-Link disconnected because you plug only USB cable directly to nRF52)? Which example HEX files work and how these with Soft Device misbehave? At least some debug trace from UART or RTT?

RE: Softdevice example doesn't start when powered by other source than MCU interface.

Francois5Co — Fri, 13 Oct 2017 06:52:48 GMT

I mean power the board with the 5V on the usb connector used for the MCU. If I powered the board with a 5V in the other usb connector (J3, directly connected to the nRF chip) only example without softdevice run on the device.

RE: Softdevice example doesn't start when powered by other source than MCU interface.

endnode — Fri, 13 Oct 2017 06:48:31 GMT

What do you mean by "power the board with other source then MCU"? You always power the board just with Volts not MCUs;) You can use 5V USB on the Dev Kit or attach different 5V source through the PIN on the header, or you can power it directly through 3V3 or you can use battery holder on the Dev Kit...

If you have problems with flashing the target then use nRFgo Studio, nrfjprog (from NRFTOOLS package) or similar tool which has some logs in case of error. That will tell us more.