monitoring milliamps with 16f877

[DavyJones]

Can anyone tell me if it's possible to monitor the ma output of a pressure transducer or any other sensor for that matter. I'm working on replacing my older style electromechanical well controls and controlling them via a pic and heavy duty 220amp relays. I have 2 wells and they don't always stay in sync.

I have access to a cheap pressure transducer 0-150psi and the output is 4 to 20ma. I can get one for a couple of dollars but I didn't see a post anywhere that anyone has written any code or has any example of reading milliamps.

If anyone has an example I would appreciate it.
thanks
David

[mackrackit]

Convert to voltage.
http://www.omega.com/techref/das/4-20ma.html
Then use the ADC on chip
http://rentron.com/PICX2.htm

[tenaja]

Put a resistor from the current supply to ground. Calculate the value so 20mA works out to 5v (or your PIC operating voltage). This will work for a hobbyist ... if you need high "product"quality, then use an op amp to buffer it.

[DavyJones]

Thank you for the great examples and links I appreciate the help this is just what I am looking for.

David

[Luckyborg]

Does anyone have the power/inclination to get rid of this guy from the forum. He has 15 posts so far and of the 6 or 7 I've come across so far not one is related to ... well anything. Maybe he has a real post in here somewhere that I missed, but it seems like he is only trying to get hits to his website. Also, in a related note I've come across the ignore user option, does anyone know will this prevent posts from appearing as new if the ignored person is the only one to post a new reply, or will I still be clicking on his quotes just to see his name and
"This user is on your Ignore List."?

As for the 4-20 ma converter. I've been wanting to try this for a while, does anyone know if I use a 1% resistor as suggested and an op amp, is this pretty much commercial ready or is there a lot of other supporting circuitry. We occasionally purchase a 4-20 ma to serial converter for like $280. It works well and has a lot of unused features, but it seems like I could make a good sized batch of them for under 200 and that would be paying more than I should. I I would just hate to hear complaints from the field that there 0 to 60,000 pound application sits at -3 instead of 0.

David

[Acetronics2]

Hi, Lucky

The most upper right symbol on the post border ... ( exclamation mark in a red triangle )

is the Warning for moderators ... just click it and write " SPAM " or Whatever you want ...

Alain

[DavyJones]

Does anyone have the power/inclination to get rid of this guy from the forum. He has 15 posts so far and of the 6 or 7 I've come across so far not one is related to ... well anything. Maybe he has a real post in here somewhere that I missed, but it seems like he is only trying to get hits to his website.
David

Are you talking about me?

[Luckyborg]

No, it was about someone else, it looks like the moderators took care of the person and deleted his posts. Your posts are all valid.

[Acetronics2]

Are you talking about me?

Hi, David

Keep cool ... this thread ( between others ) was spammed and our moderators have wiped out this junk ...

"this guy" is , of course, not you : I've counted 15+ spams on the whole forum ...

Alain

[DavyJones]

Hi, David

Keep cool ... this thread ( between others ) was spammed and our moderators have wiped out this junk ...

"this guy" is , of course, not you : I've counted 15+ spams on the whole forum ...

Alain

hehehe ok sorry about that I thought I was doing something wrong or asking the questions the wrong way. I didn't want to get booted if I wasn't following the rules. The people here are great and I could not have completed one project without them.
Thanks