[CAVEAT: Very basic question from someone who is not yet even at the "newbie" stage. Please forgive if the question is too basic and/or poorly formed. --thank you!]
Greetings!
I work for a small start-up firm with very little by way of capital resources (translation: cheap and stingy!). We are about to start production of our new product and the idea came to me to try and automate the test procedure by building a computer-driven test fixture. I'm looking for some basic advice on 1) if the project is even feasible and 2) if so which platform would be better suited for it: Arduino? Raspberry Pi? Something else I've not considered?
The test procedure basically involves hooking the unit to a power supply. Driving the unit at standard power to check functionality. Lowering the voltage to check "low voltage" functionality. Raising the voltage to check for "over voltage" conditions. Then reversing polarity to check reverse polarity protection.
Since the fixture is computer-driven, seems using a raspberry pi is the choice (running something akin to LabView maybe? Is there a open-source freeware version of that available?) But then I have also read that for interfacing with and driving hardware the Arduino board is the better choice.
Any and all advice appreciated!
Thanx!
An Arduino would probably be better. The inputs/outputs are a bit more durable (40ma max sink/source vs 16ma for the Pi) and allow up to 5V operation (3.3V for the Pi). The Pi has no ADC; Arduino has 10bit resolution.
If you already have a computer available then you would use the USB connection (which behaves as a serial device) to the Arduino to communicate/control it; you can essentially make it a dumb I/O board if you want.
You could try a multimeter first.
I've never found a cheap & stingy boss willing to invest on unknowns. They pretend to and then screw with the effort. But maybe it's different for you.
So check into using an UNO as an ISP (chip programmer) to program cheap AVR's to serve as test equipment.
In quantity 10 or more I have gotten ATMega328P (the UNO chip) at $2.50 or less each. They can run at 8 MHz on internal clock which means that with power and ground and a loaded program they run and only need what other pins you use connected. But use sockets if not sockets on boards, it makes it easier to change out chips.
For your needs, cheaper AVR's might do. ATTiny85's cost about half as much but only have 8 pins (328 has 28 pins) and scant memory but the same speed, perfect for extra simple tasks.
I have this feeling that someone is putting themselves up for a ton of unpaid overtime but that's just my experience talking. Think about it and get any promises on paper, signed, witnessed and notarized after carefully checking for the loopholes you will regret later. Remember, it always seems better when you fixate on the carrot and there's only one person that can make sure you actually get carrot. Whatever you do, don't sign away your future for a nickel and a dime in some stupid contract.
running something akin to LabView maybe? Is there a open-source freeware version of that available?)
No, you can't even run a real version of LabView on the Pi.
Does Firmata and Processing still work?
Yes it does on a Pi, but processing is very slow you are better off with Python and real code in the arduino.