I'm a total newbie to Arduino and I'm starting my first Arduino project and I figured, meh, why make it easy?
I'm building a electric mini chopper that will be powered be a 48v 12ah battery pack. My controller can draw up to 200 amps max and I want to make a "fuel gauge" that shows both volts and amps.
Just to clarify, a fully charged 48v pack is actually around 57 -58 volts, so I want the voltmeter to read up to 60v. I would like the ammeter to read up to 200a if possible. I do understand that I will need a good quality shunt for something like this.
I've found a couple of post on different website on how to make individual voltmeters and ammeters, but I haven't found any that combine the two.
I'm planning to follow this tutorial to make the speedometer/tachometer:
So I would like to use the same display if possible.
I have "OK" coding skills in a couple of different languages, (I put the OK in parenthesis because my son is a developer for Openstack SDN and he laughs at my code! ), so I'm not afraid to approach this project as a beginner.
I think you should make it easy and start with a simple project .
The problems you will have are any speed controller will be chopping the power supply and you will not get a steady, easily measured current . There will be a problem with measuring voltage and current - thinking of how you wire it up ( common 0v line ) . Any shunt will limit the motor current in a low voltage hi current circuit and you will need to amplify the signal. All this stuff adds weight- just measure the pack voltage and make do with that ( most controllers include that anyway) .
There are plenty of non-invasive ways of measuring current that don't require a shunt. Have a look for "non-invasive current sensors". Since many of them are designed for automotive use 200A DC is not a problem.
But I wouldn't have anything to do with that "instructables" thing. There are many better ways of making a speedometer.
I've found a couple of post on different website on how to make individual voltmeters and ammeters, but I haven't found any that combine the two.
The Arduino has multiple analog inputs.
It's actually easier to measure high current. A hall-effect current sensor is probably the way to go. If you use a shunt, it has to go on ground-side, because the Arduino can only measure voltage referenced to (its) ground. And hopefully, you know how to calculate power dissipation in the shunt.
I'm building a electric mini chopper that will be powered be a 48v 12ah battery pack. My controller can draw up to 200 amps max and I want to make a "fuel gauge" that shows both volts and amps.
Sounds like the OP already has a controller, all that is needed is a battery voltage and load current monitor.
slipstick:
There are plenty of non-invasive ways of measuring current that don't require a shunt. Have a look for "non-invasive current sensors". Since many of them are designed for automotive use 200A DC is not a problem.
Like this?
slipstick:
But I wouldn't have anything to do with that "instructables" thing. There are many better ways of making a speedometer.
Do you have any links to point me in the right direction?
raschemmel:
Do you have any filter caps or flyback diodes across the motor ?
No, the motor is a DC brushed industrial permanent magnet motor. It connects tho the battery and controller like this:
), so I'm not afraid to approach this project as a beginner.
