Aloha -
The product page for the Sharp GP2Y0D810Z0F Digital Sensors (https://www.pololu.com/product/1134) describes optional (low-)power down of the board. Before cutting traces and soldering a wire, better ask first. Is the entire board powered down?
I want to determine if the sensor is reading incident IR from an obstruction, or ambient IR from doorways and windows. I did this with some recycled LED/phototransistors, removing power from the LED, and a nested if statement re-polling the sensor. Wondering if possible to do same with the Sharps.
Thank you!
The enable feature on the carrier board for the Sharp GP2Y0D810Z0F digital sensors turns on and off power for the entire sensor, not just the emitter. You will not be able to get readings from the sensor when you have the enable pin toggled off. These sensors are pretty resistant to interference from ambient light. I recommend trying the sensors before trying to add additional methods of filtering ambient light.
So, I am looking at the data sheet, and if I get this right, the trace cut and enable pad are located just before pin 14 of the module? Does this imply that I can solder a wire at the pad, and carry that wire to a digital pin, allowing digitalWrite() HIGH or LOW? So, there would be four leads total serving the sensor, if my thinking is correct.
There is a note that “pulse current” is 70mA for the IR emitter diode, which seems to be asking a lot from a digital pin.
With a voltage divider across the battery supply, and monitoring over an analog pin, I want my bot to navigate to a sunny spot and charge via top mounted PV panel (RS 9V 1.5W). Kinda WALL-E style. Sensors to get there are temp and light intensity (phototransistor). So, you can see the potential for problems that I kinda anticipate with the Sharp sensor in full sunlight. Further, and this is an even greater challenge for me, I want to store in EEPROM wheel encoder data to get back to that spot if needed. EEPROM is cleared when battery is nearing full charge. All this packed into a 1284P in my little 6x2 Zumo. Maybe EEPROM is not the way to go, but is a start for conceptualizing this project.
Cutting that trace disconnects pin 12 from VCC, not pin 14. We do not recommend powering the sensor from a digital pin; as you noted, the sensor draws more current than digital pins typically supply.
By the way, the “Advice for the characteristics” section the of datasheet mentions that direct exposure from light sources like the sun can affect the measurement. However, from our experience, these sensors do a pretty good job of filtering out sunlight, and we have had customers use these sensors outside.
