Transimpedance Amplifier
- Connect a 3.3V power supply to VCC+ and SHDN terminal
- Connect a multimeter (set to measure current) to the 2 terminals of the photodiode
- Connect a multimeter (set to measure voltage) to Test Point 2 and GND of the amplifier
- Place the setup under lights with different intensity
- Record the current and corresponding voltage values
- The conversion between current and voltage should be $V=IR_f$
ADC(VSENSE) Input Signal Testing (how to use an oscilloscope)
- Get a oscilloscope and the cables/probes
- Connect the cable to channel 1
- Press “coupling” button besides the screen to show the signals
- Connect the probe to “Probe Comp” at the bottom right of the screen, make sure the wave displayed is a square wave. Otherwise, adjust the probe using a osco driver (the special driver used to adjust the probe) to adjust the probe, until the wave becomes a square wave
- Adjust trigger level to set trigger line at the center of the screen to stabilize the wave
- After testing transimpedance amplifier, connect the probe to VSENSE terminal
- Adjusting external light source so that the photodiode could provide different currents
- The magnitude of voltage displayed on the oscilloscope should be proportional to the intensity of light
Solar Cell Testing
- Assemble the solar cells as indicated by the circuit diagram
- In a sunny day, place the solar cell board under sunshine, ensure that no parts of the board are under shades
- Use a multimeter, measure the voltage across 2 series connected solar cells