Custom Instrument Cluster
I'm going to be building a custom instrument cluster for my 1951 Mercury M-3 truck. I'm using the motors and pointers from a 2005 Explorer Sport Trac cluster. Here's a preliminary layout (subject to change) just to give an idea I'm going for. The compass and temp display is a separate component from an overhead console and is an idea I'm liking at the moment.
The instrument cluster is going to consist of 6 bi-polar stepper motors (with drivers) and a display (VFD or LCD) with toggle button driven by PIC microcontroller (multiple if necessary).
Components I currently have: (not necessarily used)
6 - Fraen AMD 6405-1512 stepper motors
2 - Pic16F684
1 - 2x7 line alphanumeric VFD Futaba 2-st-177gina datasheet unavailable
1 - 4 pin momentary push button switch
1 - CB-25AP-12-A Piezo speaker
For the stepper motor controllers I'm looking at using Allegro 3967. Looks to be rather easy to control and having a working temp of -20'C should handle a Canadian winter.
Guage Sending unit inputs:
Speedometer - 8000 pulses per mile
Tachometer - 8 pulses per revolution - Engine will be governed to max of 6000 rpm.
Oil - 70 ohm low and 10 ohm high
Temp - 75 ohm low and 10 ohm high
Fuel - 20 ohm empty and 150 ohm fuel
Battery - Needs to read 12v to 15v
Oil, Temp and Fuel are pretty standard ADC inputs although I'm sure will need to add in additional resistors to play nice with the PIC. With the fuel, they normally have an anti slosh module to even out the readings due to the fuel moving around. Is this better to deal with in hardware or software? With software I probably could lower the refresh rate to accomplish this.
Now with the battery, what needs to be done for the PIC to read 15v without causing damage?
Speedometer and the Tachometer will have to be limited to counting within a certain time frame as I won't exceed PICBASIC PRO's max of 65535.
The odometer I'm not quite sure where to start cause the last reading will need to be stored and continued. A trip meter would also like to implemented and reset with momentary push button.
As for the display it would be nice to use the one I currently have as it matches the compass display. I can make a diagram showing its pin order and I did find a 2x20 display datasheet on their website which could be used for reference.
Any tips or suggestions are much appreciated.
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