Source code for Yaris Tachometer

[CTScott]

Originally Posted by metalshark

As beta test consumer I might be able to cost it low. The biggest problem is the BS2 chip costs $50. I need to re-prototype this project using the new Parallax Propeller chip since they just dropped the cost to $7.95. The propeller has so many beans you could put the entire Toyota engine management code on it if they would let you have a copy. The parts at-cost is roughly $80 without display LED's AND you'd want me to load the program into the BS2 EEPROM for you too. It is a neat integrated prototype though and cops always ask what it is because when the key is on and the motor dead the display chases left to right and right to left like the original KIT. The cops have to know its not an illegal mobile police scanner. They give it a thumbs up. In a Propeller version I would integrate the dash dimmer control into the unit.

Switch to a Microchip PIC microcontroller. Same or better functionality for <$5 max and many of the PICs can directly drive LEDs with the outputs.

For example the PIC16F57 is $1.55 and has 20 I/O Pins and runs at up to 20mHz. If you're not comfortable with C or assembly programming, there is even a basic compiler for the PICs.

http://search.digikey.com/scripts/Dk...IC16F57-I/P-ND