Sphere ADC questions

Hi Stephen,

According to the datasheet snippet in your post, the MCP3008 uses SPI, and that would need to be configured on the Azure Sphere (i.e. google for 'Azure Sphere SPI' to get detail on this).

In short, you'll end up having to check the Azure Sphere documentation to identify which pins relate to the SPI interface, connect those to the MCP3008 and then use code snippets as examples to enable the SPI. If no-one has done this with MCP3008 then the datasheet will need to be consulted to write the code for the Azure Sphere, or code could be attempted to be ported.

Also, there are other sensors available too that are more all-in-one, so you don't need to have a separate MCP3008 device. An example is this Maxim pulse sensor boardMaxim pulse sensor board which uses an I2C interface. It could be another option depending on your requirements.

If you're new to electronics, it's quite important to spend some time reading up (even if it is just the Wikipedia page) on SPI and I2C because they are extremely popular inter-IC communications methods, many devices use them. Also, the Azure Sphere documentation on SPI and I2C would need to be examined, to get familiar with the API (it will be different to the Pi in some ways, since there's no real standard for this like POSIX).

Hello Shabaz,

Thank you so much for your response. Interesting answer to my 2 questions, very informative. I might have confused the questions by giving a description of another project from the sensor vendor, that I have working on the Rasberry PI. I included it only to describe how the sensor was connected to an  ADC. I will read up on the SP1 and I2I interfaces you mentioned.

I am not interested in Connecting the sensor to the MCP3008. and then to MT3620.

I would like to connect the sensor directly to the Avenet Azure Sohere MT3620 Kit. I understand there is ADC capabilities and would like to connect the sensor to a  analog input.

but don't i know where on the kit to attach it..And if it's even possible.

Does anyone in the group know how to connect the signal from the sensor mentioned in my initial POST?

Kind Regards

Steve

Refer to MT3620 datasheet for detail on Mediatek pages,https://www.mediatek.com/products/AIoT/mt3620

There are two suggested ways on programming, RTapp and High level app, you'd better understand the dual-core operation before you start.

Technically, all the GPIO pins can be reconfigurated, While use the on-board configuration would save you time on it.

Try ADC pin on click dock first,

For CM4 core, Eight-channel, 12-bit, 2MS/s single-ended successive approximation ADC using internal 2.5V or external 1.8V reference

Thank you so much for your advice. I will head in that direction. and experiment with the Mediatek ADC driver interface.

I have located the Mediatek pages and started reading this morning. I will use this as a reference.and try some of the ADC examples. I learn best by using sample projects.

I've noticed that all the Microsoft samples seem to use the seed Kit and I'm using the Avnet kit . Makes it confussing to make the connection to the KIT IO.

Question:

when you say "Try ADC pin on click dock first,"

do you mean:

Attach the purple signal wire from the sensor  to the AN pin on the click header described below?

try the AN pin u will know

A question posed to bwillessApr 23,

Hi Brian

Hope this finds you well during this pandemic.

I tried to send you a direct message but could not, so I'm sending it here.

I'm hoping you can guide me along here. I tend to lean by using sample projects and have been using both the Advanced Tutorial Avnet Azure Sphere Starter-Kit: Advanced Tutorial .and the all 3 blogs in the Avnet's Azure Sphere Starter-Kit (Out of Box Demo... series. Through studying these project , I have been able to learn a great deal about CMake (config, Build etc.) Debugging, Hardware Config, A7 and A4 programming,on board sensor communication.etc.

Which leads me to my reasons for sending you this message.

For a challenge Beats Per Minute --Home Is Where the Hack Is Chal...
I am using a Heart rate sensor from a Rasberry PI project and would like to use the sensor to connect DIRECTLY to the Avnet kit. I have sent out Inquires to the Azure Sphere group  as described here:Sphere ADC Document.and Sphere ADC questions

I have received 2 replies of which one recommends connecting the sensor as quote "Try ADC pin on click dock first,"

I assume he means to Attach the purple signal wire from the sensor  to the AN pin on the click header?

I describe this in my Blog Post.

Do you agree?

I'm stuck on the sensor Input now? Once I get that solved I can experiment on reading the sensor input from your examples. Help with that would be very helpful also, but I need to get past getting the sensor connected first..

• 

  bwillessApr 23, 2020 6:51 AM (in response to Stephen Kruglewicz)Hi Stephen,The MT3620 uses some of the GPIO pins for ADC inputs as well.  Look at the MediaTek example highlighted below for details on connecting ADC devices to the Avnet Starter Kit.

  • Documentation
    • Microsoft documentation on ADC
    • MediaTek FreeRTOS ADC Example
      • This example has great documentation on how to connect an ADC device to the Avnet Starter Kit!
  • • • I just looked at this code for the first time and it looks like it's iterating over all the ADC interfaces and reading each
    • Microsoft High Level ADC Example
    • Microsoft BareMetal ADC Example
  You could also use an existing Heart Rate example application . . .
  • You could also use the Avnet Starter Kit example here, by Jim Flynn, that uses the HeartRate4 click module ($21) on the Avnet Starter Kit.
  • This is a working high level application
  Hopefully that will get you moving again!  Let me know if you have any more questions,Brian