Pic Ammeter

[RYTECH]

I'm interested to know how much current my project consumes... is it possible to rig one of my other anolog inputs with some kind of shunt and opamp to do just this? can someone post a schematic?

[RYTECH]

specifically I'd like to monitor the total current consumed of the 12v source, i'm already monitoring the voltage of the 12v source using a voltage divider and my pic's a/d module

Can somebody post a configuration for me to get the current consumption data? ... PIC16F872, 12v's wants to meter power into 7805, also if this is "easy" i wouldnt mind metering the current in from my solar cells which are connected... so i get Current in and out...

thanks please tell me how or point me to a working example (i've googled.. but nothing helpful besides the info i need a shunt and op amp)

[Ingvar]

Maxim have several "current sensors", one that springs to mind is MAX4172.

[ero]

@rytech,
I have made similar system by using a pic. I explain you how it can be done.
The components;
1 pce. LM358 opamp
2 pcs. res. 1K 1/8 watt
1 pce res. 0R1 (0,1 Ohm) 5 watt or bigger.
1 pce. res. 6k8 1/8 watt.
1 pce variable trimpot 4k7

The schema can be loaded from following link.

http://rapidshare.de/files/10143993/ampoku.EMF.html

The output of the LM358 will be connected to ADC input of the pic.
The max. current which is the total capacity of your power supply, will be regulated by 4K7 trimpot. This circuit is arranged for measuring max. 5A current.
You can connect one ammeter serially to the circuit and connect also one current source (can be one auto-lamp) and regulate the total current by trimpot.

ERO

[RYTECH]

Thanks for your prompt suggestions, i will investigate both options and post if any trouble in implementation.

[RYTECH]

I've obtained several max4172 SOIC IC's. Could somebody help me get started with the current sense of my 12v source. The mesurable range should be between 0 and 1 amp (lets start with just metering the logic part of my project).

I will be using the 2nd A/D channel on my pic as the first is used to sense battery voltage.

what i need is a schematic with some explanations, the datasheet seems compllicated and doesnt explain how to interface to the pic.

Thanks