Connecting MCP3008 and Dragonboard


#1

Hi there,

i bought a Dragonboard and i try to connect the Dragonboard and a MCP3008.
I have done it with a Raspberry (where it worked like a charme) and now i want to move the installation to my Dragonboard.

if i read out the MCP, there are only 2 possible values i get back: either 0 or 1023.
I can’t tell, why i get back 0 or 1023 or even have any influence on which value comes back.
i am using the right pins on the low-speed connector.

I already got another board… same thing.

Any hints where i could start looking for problems?
Is the SPI on the Dragonboard different then the one used on the Raspberry?

Thanks for your help!

BR
Rainer


#2

Hello Rainer,

There are two main differences when using the SPI on the Dragonboard when compared with the RPi.

  1. You will need to level shift the voltages. The 96Boards work at 1.8v rather than 3.3v on the RPi
  2. You will need to enable the SPI interface on the board. On the Dragonboard you need to modify the kernel/device tree.

There is a guide on enabling the SPI at:

Regards,
Barry


#3

Hi Barry,

i already enabled the SPI interface on the board (built the device tree, …)

so i guess my problem are the different voltages.
Can you recommend a voltage shifter?
Can you tell me how to wire it up?

Thanks,
Rainer


#4

In the past I have used:

There are some other suggestions at:


#5

Hello guys, I would recommend the use of the Audio Mezzanine, the cost is very low and working fine.
https://www.arrow.com/en/products/audiomezz/seeed-technology-limited.


#6

I wont recommend using very long (>2cm) connectors with the audio mezz…