This is a small pcb that is designed to be used on an electric go-kart to display a stopwatch, motor RPMs, and cart speed as well as record this data on an SD card with a time stamp for analysis. The project is Arduino based and is ran off of 7-59 VDC or directly from a 5V source through any of the 5V or VIN pins on the data logger shield (this is not a protected input). It is designed to have wires soldered in the spots for the power input, the power switch, the start & stop buttons, and the hall effect sensor that goes to the axle. The device is calibrated through variables for wheel diameter and gear ratio from the motor to the axle. To upload the sketch use the ICSP (In Circuit Serial Programmer) headers found on the data logger shield.

Operation of Device:

1. Flip toggle switch to on position
2. If device displays "no card" with blinking lights, insert SD card and hold down the clear button
3. If the system continues with no SD card, the set-up portion of the code catches this and sets the device in an error state, requiring a reset.
4. System now sets up and displays should go to ---- on all three and then 00.00, 0000, and 00.00 in order from top to bottom
5. The program is now in it's "run w/o recording" mode so it will display the current motor RPM and cart speed without updating the clock or saving data.
6. When the start/stop button is pressed, the device instantly detects this and switches modes after it finishes a cycle. A cycle lasts however long it takes for the sensor to detect a magnet twice or until it times-out at 1.8 seconds. This makes the minimum detectable speed 1.09 mph
7. The device is now in it's "run and record w/ time" mode where it displays the clock from the start of the cycle as well as recording information in th format: "unix time, mm/dd/yyyy, hh:mm:ss [clock], [RPM], [Speed] " in a .CSV (comma-seperated value) file
8. If the start/stop button is pressed, the device detects this and stops the clock as well as stopping the recording of data. It then switches back to the default "run w/o recording" mode at the end of the cycle.
9. If the clear button is held down for on cycle (as described above in 6), the device performs the same task as 8 but also resets the clock to 00.00