Laser Diode Temperature Controller

Laser Diode Temperature Controller

Project Timeline:

Fall 2011
- Circuitry Research
- Part Research
- Circuit Design
- Schematic Drawing

Spring 2012
- Breadboard wiring
- Circuit implementation
- C/Assembly programming
- Surface mount adapter chips
- Datalogger design/implementation/interfacing
- Basic functionality demonstration to professor...

New Updates
- Platinum RTD temperature sensor
- Instrumentation amplifier temperature sensing front-end
- Many new software functions implemented
- Fan control circuit
- LCD brightness control circuit
- LCD test modes (verfies all pixels on LCD work)

Ongoing Work
- Integrate USB hardware on PCB
- Design custom USB datalogging software
- Create USB control interface (Full control of device using PC GUI)
- Send PCB to fab house



Demo:



LCD Display:

Setpoint Menu:

LCD Display

Actual Temperature Menu:

LCD Display

History Menu:

LCD Display

Integrated LCD Interfacing PCB:

LCD Display

LCD PCB Layout:

LCD Display PCB Layout

Integrated Temperature Controller PCB:

Temp Controller PCB 1.1

Temperature Controller PCB (Rev 1):

Temp Controller PCB 1.1

Temperature Controller PCB (Rev 2):

Temp Controller PCB 1.1

Class Poster

LCD Display

Temperature Stability

LCD Display

Using the EasyLogger, I was able to test the performance of the system with different PID parameters. The graph shows a linear ramp up, followed by a steady decline to the setpoint temperature. The quick disturbance at the end of the test was caused by placing my hand on top of the temp sensor and metal plate. Due to insufficient mating of the temp sensor and the surface, the graphed temperature is off by a degree or two.