pressure logger

[billyboy]

hi guys it as been a some time since ive been on here so here goes i would like to build a pressure for nat gas range from 0-75 mbar i seen a project on here for a gps logger with a mcc card and i thought what a good idea so i thought just remove the gps unit and put a pressure tranducer in it place but the transducer is 0-10v 4/20ma so i will need a adc chip do you think this will work??????
thanks billboy

 

[Diver300]

Yes, that would work, but it would need significant program changes. There is a lot of timing and storing stuff on a card that you could use from a GPS logger.

You would have to bypass the parts of the code that reads in the GPS and add stuff that reads the ADC. PICs running on 5V often contain ADCs that can read 0 - 5 V.

 

[billyboy]

HI Thanks for you reply, i had a look at oldspring web site and he as done a temperature logger with a ds1307 for the date and time and use sht15 for the temp i think this is the right road to go down, i had a look at adc chip https://www.electro-tech-online.com/custompdfs/2008/11/rcv420.pdf could you have a look at this if you think this is the right chip for the job thanks billyboy

 

[Diver300]

I would suggest just a simple 250 Ω resistor will convert the 4 - 20 mA to 1 - 5 V.

Then use the ADC and offset the result with software.

The TI device will give you less voltage drop and slightly better resolution, but unless you need one of those it is unnecessary complication.