I’ve just started to dabble with arduinos on my model railroad, and I was wondering… has anyone tried building an arduino-based RRampMeter?
I piddle around with Aduinos but I wouldn’t try to use one for a DCC ammeter. The Rob Paisley circuit fills the bill quite well.
http://www.circuitous.ca/DCCammeter10.html
With it all you need is regular DC meter. I have a digital meter on my control panel connected to a Paisley board.
The digital LCD meter on the right on the left side of the panel measures DCC current switchable 0-2 amps and 0-4 amps.
Because of the micro chips I would advise purchasing the board from Rob with the micro chips installed. At 80 I couldn’t hold my soldering iron steady enough to install the ZXTC1009 micro chips, well worth the $8 (US) with the pin head size chips soldered on the circuit board.
There’s little point to using an Arduino in this case. While you could take the millivolt output of Rob’s circuit and run it through a precision resistor and measure with the analog input on an Arduino, just hooking one of those small LED panel meters to it is probbaly more accurate. There;s nothing like a microcontroller in the RRAMPmeter either, just a similar current detector and a compensated voltmeter. The one little LED voltmeter I got on eBay has a trimmer to adjust it, so you could apply the high speed diode bridge to the input and then adjust it to compensate for the diode drops and bingo, DCC voltmeter. You would need a way to calibrate regardless - and about the best way to do that is with an oscilloscope.
–Randy