MCP4725 and INP12 rev c on raspberry pi 3B+

How do I install the pull ups? What do I connect them to?

This is my first time working with anything like this and I don’t fully understand how it works.

Okay. I have tried with arduino. I have not connect the board to my motor because I am lost on exactly what the arduino code is doing. I cannot tell if the DAC board is working or not. It is powered on just as it was with the raspberry pi.

It is doing 4-20mA it appears instead of 0-10 V

you can use this arduino code to scan the i2c devices

the 4-20mA and 0-10V use same chip. so the code is also same.
//for (int i=0; i <= 4096; i++) ///////to use this code with 0-10V Hardware
for (int i=290; i <= 1500; i++) ///////to use this code with 4-20mA Hardware

Hi:

Did you enable I2C on the Pi?

Figured you have. But, needed to ask.

Thanks

Okay, I have enabled i2c on my pi following those instructions. I had already done it but I walked through that to double check. I also used the arduino scanner and it is picking up the device. Is there a way to check if the shield is the problem? I also noticed in the adafruit directions for setting up i2c that it asks you to enable the ARM and then to have the kernel loaded by default. I don’t get the question of whether it should be loaded by default? Is my pi even saving this setting?

i think your pi might be faulty. I will recommend trying on a diff pi.

So, what happens when you run:

sudo i2cdetect -y 1

on the Pi? Do you see anything that is not zero?

If you have a non-zero entry, then the Pi is detecting an I2C device and everything is running fine on the Pi. (Nothing else to do.)

With this in mind, I’d be inclined to focus on ‘addressing’ the I2C device.
Use the i2cdetect output in your program to address the board…

image
This is what I see when I have the MCP4725 plugged in as so


When I plug it into the “out” side I get the top but the power button on the MP4725 is no longer lit up. The bottom happens when I unplug the MCP4725 from the pi completely.
image

I am going to try to plug the scl pin and sda pin from the pi directly to see if the shield is what is causing me problems. I will make sure to install the pull ups when I do this.

Any other ideas? Or at this point is it pretty certain that the pi is the problem?

image
This is what happened when I used the SDA SCL a 5v and GND pin directly from my pi without the shield. So obviously it is not my pi and the problem lies with the shield. This is a relief.

I have a general question about this though. I need my SDA and SCL pins to connect to the touchscreen I will be using to interact with the pi in my final implementation. Can I use the SDA and SCL pins for two different things and what would be the best way to connect that? Or do I need to find a different shield?

you dont need a separate shield. i2c is multi drop protocol. you can have multiple slave as long as they have diff diff i2c address.

please submit an RMA for i2c Pi shield and we will repair it for you.
https://ncd.io/contact-us/product-returns/

So I can connect my screen and my DAC to pin 2 and 3 (BCM)? How would I physically go about connecting 2 things to the same pin?

I will fill out the RMA.

You can use the DAC out port. it has SDA and SCL pins there.

Thank you so much. I will do some testing of that.

Hi jgatzemeier:

Glad to see that things are starting to move forward.

Agree with Bhaskar in that you can use the “out” of the MCP4275 for the touch screen.

Because I has burned myself on this… please make sure you can talk to the MCP before adding the touch screen.

Again, glad to see that your project is moving forward.

I am having trouble communicating with the board. I am trying to use the adafruit MCP4725 library. Are there any python libraries you recommend?


this is my current code

please checkout this post.

This might be a bit late, but I had the same issue and was able to fix it by closing the two jumpers for the pull-up resistors on the board. In the most recent picture it looks like you have them open.a964464913c3306bb7d8a9d7bca4195452c891cf

Is the output of the MCP4725 an isolated analog signal?

The output of the MCP4725 is not isolated.