Hello
I am trying to come up with a slim HMI with "plc", and none of the existing HMI panels with plc are small and or cheep enough.
So i am looking at Raspberry Pi. I need to have Analog out, and digital in/out
Analog out properly need to be 0 - 10v or 0 - 20 mA, standard for the equipment that need to be attached.
Now i am looking at this since Raspberry Pi do not have analog out by default.
https://www.abelectronics.co.uk/products/3/Raspberry-Pi-Model-A-and-B/39/ADC-DAC-Pi-Raspberry-Pi-ADC-and-DAC-expansion-board
This may be an option? could I use this board with something like:
https://www.tindie.com/products/ozzmaker/piscreen-35-tft-with-touch-for-the-raspberry-pi/
or
http://www.adafruit.com/products/1601
I am new to Raspberry Pi, so i do not know what "fall pits" there are or what limitations are.
-Thanks
Is ADC DAC Pi what i need ?
3525 Views - Created 05/10/2015
31/08/2015
Posted by:
Morten Hundevad
31/08/2015
Posted by:
andrew
Location:
United Kingdom
Hello
I don't think the ADC DAC Pi will work with either of those displays as they both use the SPI port and so does the ADC DAC Pi. You can only have one SPI device connected to the Raspberry Pi so there would be a conflict between the two expansion boards. The analogue out on the ADC DAC Pi also only goes up to 2.048 volts.
I don't think the ADC DAC Pi will work with either of those displays as they both use the SPI port and so does the ADC DAC Pi. You can only have one SPI device connected to the Raspberry Pi so there would be a conflict between the two expansion boards. The analogue out on the ADC DAC Pi also only goes up to 2.048 volts.
31/08/2015
Posted by:
Morten Hundevad
Is there any other options you see that i could use ?. the display is a must, just like the analog out is a must.
As for voltage i could make an "amplifyer" or something correct ? or use 2.048 V and add something that makes it 0.20 mA would propearly be the simplest.
Any sugestions would be aprisiated.
-Thanks
As for voltage i could make an "amplifyer" or something correct ? or use 2.048 V and add something that makes it 0.20 mA would propearly be the simplest.
Any sugestions would be aprisiated.
-Thanks
31/08/2015
Posted by:
andrew
Location:
United Kingdom
You could try finding a DAC chip that uses the I2C bus instead of the SPI bus.
Texas Instruments do several I2C DACs, so it may be worth trying to find one that fits your needs and order some free samples to play with.
As the I2C port on the Raspberry Pi is 3.3 volts you may need to use a level shifter if you choose a DAC that works at a higher voltage.
Texas Instruments do several I2C DACs, so it may be worth trying to find one that fits your needs and order some free samples to play with.
As the I2C port on the Raspberry Pi is 3.3 volts you may need to use a level shifter if you choose a DAC that works at a higher voltage.
31/08/2015
Posted by:
Morten Hundevad
Could it be something like this?
http://www.adafruit.com/products/935
and something like this for input ? or is there only one I2C also ?
https://www.adafruit.com/products/1085
http://www.adafruit.com/products/935
and something like this for input ? or is there only one I2C also ?
https://www.adafruit.com/products/1085
31/08/2015
Posted by:
andrew
Location:
United Kingdom
Those two should work together and they are both 3.3V compatible so you can control them directly from the Raspberry Pi I2C interface.
31/08/2015
Posted by:
Morten Hundevad
Thanks for your support!!!
Note: documents in Portable Document Format (PDF) require Adobe Acrobat Reader 5.0 or higher to view.
Download Adobe Acrobat Reader or other PDF reading software for your computer or mobile device.