Digital Lap Timer Update - 10/3/07

Ryan and I have been working on a lap timer for our contests in October.  The timer uses the Chibot controller with a Mega88 MCU, runs on 4 AA batteries (alkaline or rechargeable) and supports 3 sensors. It is designed for 3 modes:

1. Lap Timer - Time on 3 individual laps and a total time
2. Start/Finish Timer - Captures the time between trigger the Start sensor and the Finish Sensor
3. Lap Timer with Speed Trap - Works like the Lap Timer with the addition of measuring the speed of robot as it passes over a pair of sensors embedded in the track (this mode is not fully baked yet)

Two sets of wireless sensors are complete. The sensors use the Laipac 433MHz ASK transmitter/receiver pair, 1 RF transmitter in each IR receiver and a single RF receiver in the timer. The ASK transmitter is active only when a high signal is sent. This allows two transmitters at the same frequency to be used with one receiver.


LCD 4x20 White on Blue with Backlight
Controller Chibot Controller with Mega88 MCU running @ 20MHz
Resolution 1/1000 second
Power 4 AA/DC adapter, DC-DC converter with Soft Switch
Sensors 3
UI 3 Buttons: Mode, Start, Reset

Still To Do:

  1. Enable Auto Off when there is no activity for a set amount of time
  2. Low Battery Alert


Timer in Clear Case


I picked up a carrying case for it from Plasticase. This will keep the timer from getting scratched up and make it easier ot carry.

Timer in Case