4ma to 20ma input analog sensors

Support Sensors
1

hi everybody,
I am new and I am glad to be here with you.

I have been working for a while with Raspberry Pi and I have just got version 3.
I need to have a very robust sensing device that i would be happy for any help I can get.

I would be happy to know if you have any idea which sensor I can use for 4ma to 20ma working with RPi?
I am developing in Python and I would be happy to know if there are any expansion boards from Pololu that I can use with the Pi to enable UART and Sensor connection with input of 4ma to 20ma.

i have a need for at least 8 channels to connect.
Any Idea?
I am also hopping to do Modbus communication with full dropping and Multi dropping of RS485 devices.
I would be happy to get any assistance on that as well.

thanks in advanced
Arye

2

Hello, Arye.

It sounds like you want a board that will let you use your Raspberry Pi with a sensor that provides it’s output through 4-20 ma current loop (as described in this Precision Digital application note). We do not carry any boards that do that.

Our 23201a Serial Adapter converts logic-level signals like the TTL serial on the GPIO pins of the Raspberry Pi to the higher voltages required for RS-232 and similar serial ports. That might be useful for you if you can find a RS-232 to RS-485 converter from a third party. I do not know how easy it would be to find a TTL serial to RS-485 converter.

-Nathan