Shift Indicator using Arduino Nano

See this post about request for shift light method: http://www.forabodiesonly.com/mopar/showthread.php?t=325823

This post is an example of how to program an Arduino nano for use as a shift light driver. Nano board are inexpensive, a year ago $10, now about $5 each. This post does not cover conditioning of an ignition signal for use as a logic input to the micro, it varies much with ignition system.

Step one was to program an ignition simulator using a second nano. This was easy to do. The simulator allowed me to easily test the shift indicator without using a car. The tach drive signal from the simulator puts out four 0-5V pulses per revolution, from about 650 to 7000 RPM, then repeats. This simulator could be used to test ignition boxes, or bench test EFI ECUs.

Shown are two nano boards. They are about the size of a thumb. They easily are connected and powered and programmed via the USB on a PC. I use the CodeVisionAVR C compiler, to write programs and load into the nanos. There is an Arduino IDE, but I have limited experience with that, and find no need for it.
View attachment 20150906_194826.jpg
The top board is the shift indicator, the bottom the ignition simulator. The output of the sim is connected to the input of the shift indicator, the second wire is common ground.

There is a serial connection via the USB not only for loading code but also for communicating with the micro. I used it to display the RPM, so with a terminal the shift indicator becomes a very accurate tachometer.
View attachment ShiftLt1.jpg
View attachment ShiftLt2.jpg
The two screen shots show the parts of the program I wrote, the rest is typical startup and initializations that are done with the compiler wizard. Sorry view is bad.
A zip of program files is here:
View attachment ShiftLite.zip

There 4 LED indicators on a nano, TX,RX, Power, and L. The power is always lit when power is available, TX indicates the nano is sending data via serial, RX means data is being received, L is a green LED that is turned on as the shift indicator.

The Nano schematic is found here:[ame="https://www.arduino.cc/en/uploads/Main/ArduinoNano30Schematic.pdf"]https://www.arduino.cc/en/uploads/Main/ArduinoNano30Schematic.pdf[/ame]

The CodeVisionAVR compiler is found here: http://www.hpinfotech.ro/

The data sheet for the ATmega328p used on the board is found by googling "ATmega328p datasheet" my attempt to attach that URL failed because the forum attempts to view a 650 page document, and fails. I just want to list the URL. If only I knew how to use a PC ....