I'm relatively new to the MSP430. I've gone through the blinking leds, interfacing dc motors and pushbutton and potentiometer analoginput projects but now I'm trying to build a simple robot. I want to navigate the robot using a self made IR proximity sensor. So I'm trying to receive IR-light emitted by an IR-led with a photodiode (OSRAM SFH 203 FA). As I was reading through the datasheet of the Osram I found Vr = 5V. I looked online to find which is the 'R' standing for. I eliminated a few abbreviations and now I'm doubting whether the R is 'recommended' or 'reverse'. I tried to connect the photodiode reverse biased to the 3,5V MSP430 VCC but there wasn't a voltage change at my input pin at all. So, does it means that the photodiode realy needs 5V?
Then I started looking how to connect the diode to 4 AAA batteries (4,8V). I added my scheme and datasheet to this post. But as I'm afraid to ruin my MSP430 (too high voltage) I'd like to hear your experiences with this problem. I'm afraid the input pin will reach higher values then the max supported 3,5V's.
datasheet photodiode.pdf 273.64KB
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