Creating own custom-board from nrf52840-DK

[Adrian1504]

Hello,

I want to create my own board from the nrf52840. I am planning to copy the schematics given only taking into account what I need.
I went through the schematics and some questions raised:

• If I will use only SPI with my board, is it needed to include the "Interface MCU(nrf5340)" part, or only with the nrf52840 is enough?
• If I would like to implement also one button and leds, would the nrf52840 alone still be enough?
• The soldiering of the nrf52840 seems quite difficult, would you know of a solution for this? Maybe a mounting base or something similar?
• I see that your schematics are all for Altium. Would they exist also for KiCad?

Thank you so much for your time. I know they may be simple questions but I am a noob to this hardware design.

Adrian Lopez.

[mathiaso]

Hi, Adrian.

I think it might be a better idea for you to look at the reference circuitry and then the reference layout, which is downloadable from here, that belongs to the configuration you choose.

Best regards,
Mathias

[Adrian1504]

Hi Mathias,

Thank you so much for your answer! It has been really helpful. 

I see that If I choose the QFAA QFN48 package (Because it would be the easier to solder) I can not use USB, right? Then, how would the programming of the device take place?

Also, with the configuration for this package, I can use SPI, right? I do not have to add any other component to be able to read from my sensor?

Best regards,
Adrian Lopez

[mathiaso]

Adrian1504 said:

I see that If I choose the QFAA QFN48 package (Because it would be the easier to solder) I can not use USB, right?

That is correct, as the USB pins are not routed in the QFN48 package.

Adrian1504 said:

Then, how would the programming of the device take place?

You use the SWD lines and a debugger. If you have a DK, e.g., an nRF52840 DK, this can be used as the debugger.

Adrian1504 said:

Also, with the configuration for this package, I can use SPI, right? I do not have to add any other component to be able to read from my sensor?

Yes, you can use SPI with this package as well. Avoid using the pins marked with "Standard drive, low frequency I/O only" in the pin assignments list for SPI. You shouldn't have to add any extra components, as long as the sensor is SPI compatible and its datasheet doesn't specify anything about extra components.

Best regards,
Mathias

[Adrian1504]

Hi Mathias,

Thank you so much for your answer, I think I understand now. For programming it then I should connect the SWD lines to the nrf52840DK and then program through VS as if I was programming the DK?

Again, thank you so much for your answers and patience!

Best regards,
Adrian Lopez

[mathiaso]

The PS of the nRF5340 DK has a graphical explanation showing the necessary connections to program an external board with custom connections. When connected like this, you should be able to program it as normal through VS code.

[Adrian1504]

Perfect! Thank you much for your help and guidance Mathiaso!

Best regards,

Adrian Lopez