On a traffic intersection when you wait for signal to change from red to green, or when you are driving and crossing the green signal and you need to know how many seconds are left for green to turn to red, Traffic-Signal-Timer display the remaining time of current signal state.

This design is in two categories - Single Color and Dual Color.

Single color traffic-signal-timer are existing, selling and field proven designs and are based on Motorola/freescale micro controllers.

Dual color traffic-signal-timers are new design and are yet to be tried in field. The details here are for dual color model.

This design is basically a 3 digit display in two colors - RED and GREEN.

This is installed at a traffic intersection and display the remaining time for red/green light.

The complete designs consists of following

1. Micro Controller - ATMEL ATMEGA8 is a 20 pin ic with 8k program memory.

2. Sense RED/GREEN signal lights - Two opto couplers senses when red or green signal lights are on/off. Output of Opto is connected to Micro controllers.

3. Display driver - 2 ICS, TD62783 and TLC5916 drive the grids and segments of 3 digit dual color display board.

4. Power supply - converts 12V DC to 5V regulated DC for all digital ICs.

5.RS485 interface - This is an optional interface. This unit can be connected to micro controller and display data is sent by master controller.

6. Two jumpers/switches - These are used to set the unit number of the device. This becomes useful mainly when sending data from master controller. Multiple units are connected on same RS485 bus. Data is displayed when unit number of physical unit matches with that of the data sent by master controller

The information included are

1. Source code 2. Circuit Diagram 3. PCB Gerber files