QFAA-Pin mapping

[janik]

Hello,
I have created a custom board with the nrf52840 QFAA and have already flashed it successfully. I do the flashing and debugging with the nrf52840dk. Now I have written code to toggle a pin. It works on the DK. On my custom board I see in debug mode that the pin is toggled. However, I cannot measure the toggling.

The assumption is that I am toggling the wrong pin. In the description of the VSCode extension, the naming of the pins is different than in the user manual.

Of course, it could also be that I have not configured the GPIOs correctly as peripherals. I enabeled both GPIO controllers via the VisualEditor and then added the corresponding pins via the node function.

[Vidar Berg]

Hello,

To try to rule out any issues with the FW configuration, please try programming the attached hex file and see if that works.

Hex file

4682.zephyr.hex

$ nrfjprog --program zephyr.hex --chiperase --verify -r

Project

pin_test.zip

Best regards,

Vidar

[janik]

I flashed the test software, but the GPIO doesn't work.

When measuring the pins, I noticed that there were 3 volts on the decoupling pins. I used the reference design from the data sheet as circuit design.

[Vidar Berg]

Which decoupling pins, on DEC4? Also, are you able to debug the application to confirm that the program reaches main()?

[janik]

All decoupling pins have 3 volts. I can debug the program. It even goes to the main loop.
When debugging, you can see that the pins are toggled in the register.

I also flashed a Bluetooth example application onto the microcontroller and it worked. Only the GPIOs don't work.

[Vidar Berg]

This sounds like a hardware problem. The voltage on DEC4 should also be ~1.3V. Could you please create a new private ticket and upload your schematics along with the Gerber files for review?

[janik]

We have found an error on the hardware side. The reference circuit diagram is poorly represented in the instructions. If lines cross, then you put a dot on the lines. Now the voltage at the decoupling pins fits. We have soldered a new microcontroller to the circuit.

I have attached the software as a zip file. Please check if all registers are set...
We opened the example project (Blinky) with the VS-Code Extension. Then we created a custom board (nrf52840 QFAA). We activated GPIO1, GPIO2 and GPIOTE via the DTSU viewer.
However, the code does not toggle a pin. In the debugger you can see that the pin register is set, but no voltage can be measured.

4718.blinky.zip

We also need a reliable statement on which pin layout we can use for orientation. The layout from the manual or the layout from the DeviceTreeViewer from zephyr. The pin level P0.05 and so on... does not match. (Pictures in the first post)

[Vidar Berg]

janik said:

We have found an error on the hardware side. The reference circuit diagram is poorly represented in the instructions. If lines cross, then you put a dot on the lines. Now the voltage at the decoupling pins fits. We have soldered a new microcontroller to the circuit.

A dot/junction indicates a connection between intersecting wires. If wires cross without a junction, they shall not be connected.

janik said:

I have attached the software as a zip file. Please check if all registers are set...
We opened the example project (Blinky) with the VS-Code Extension. Then we created a custom board (nrf52840 QFAA). We activated GPIO1, GPIO2 and GPIOTE via the DTSU viewer.
However, the code does not toggle a pin. In the debugger you can see that the pin register is set, but no voltage can be measured.

Still sounds like a HW problem.

janik said:

We also need a reliable statement on which pin layout we can use for orientation. The layout from the manual or the layout from the DeviceTreeViewer from zephyr. The pin level P0.05 and so on... does not match. (Pictures in the first post)

The DT UI visualizes pins that can be configured in software (e.g., GPIO - Px.xx pins) and does not make any attempts to reflect the hardware layout (it does not show the package pin numbers). So, you need to refer product specification and your PCB layout.

[janik]

Vidar Berg said:

A dot/junction indicates a connection between intersecting wires. If wires cross without a junction, they shall not be connected.

I looked at the reference layout with aisler and the missing points were set. Looks to me like an export error in the circuit diagram.