SLAU664B February 2016 – August 2017
The MSP430FR2311 MCU LaunchPad development kit features pins to access the smart analog combo on the device. These pins are accessed on jumpers J7, J8 and J9 where the smart analog combo operational amplifier is connected to the onboard photodiode circuit. These pins are also connected to the BoosterPack plug-in module header pins. For applications that use the SAC and a connected BoosterPack plug-in module, be sure to check for any pin conflicts. The photodiode circuit can be disconnected from the SAC using jumpers J7, J8 and J9. The user can connect an external analog sensor circuit to the SAC by removing jumpers J7, J8 and J9 and connecting their circuit to the appropriate header pins through the BoosterPack plug-in module headers or the jumpers near the light sensor circuit.
To adjust the light sensor circuits' sensitivity the user can adjust either the software or the hardware. By changing the value of R3 and C6 the user can change the operational amplifiers low-pass filter and sensitivity to the photodiodes current. The user can also adjust the calculations performed in the software to adjust the sensitivity of the circuit to their desired level.