arduinobreakout
I'm interested in the following IR sensor breakout board with the QRE1113: https://www.sparkfun.com/products/9454
However, I would like to control the LED (on/off, PWM if possible). Should I disregard the breakout and see if I can get the QRE1113 seperately (hopefully nearby), or could I wire the LED to a pin on the Arduino (Nano)?
The DS18B20 used by the Sparkfun sensor can be used with or without external power supply. The Sparkfun seems to have three wires, so that will be ground and data and Vcc. (so far for a 1-wire interface!).
Black is ground, red is Vcc, and white is data (per comments here).
The data line will be pulled high by the resistor when idle. You're not supposed to make the I/O high! If you want a high level, switch to high-impedance input. To make the line low, set to output and set the level to "0".
May sound a bit complicated, but once you set the output level low, you don't have to touch it anymore, and set high/low by just changing the Data Direction bit.
One thing to note is that
if (pwmVal != 255) {
pwmVal += 10;
...
is not going to stop at 255, since pwmVal will be 250, then 260, e.t.c. One way to fix this would be write
if(pwmVal < 255)
{
pwmVal += 10;
}
else
{
pwmVal = 255;
}
By the way your code is written, if DEBUG is set to 0, nothing will happen (pwmVal will be set to 0). If DEBUG is set to 1, the fan speed will increase at a rate set by "wait" (which isn't defined in this code), until it gets to it's maximum. The value will also be printed to the serial port.
Best Answer
With that breakout board, you can do fairly slowly on and off by connecting the vcc pin of the breakout to an arduino pin. However the problem is with the capacitor in the schematic where if the vcc pulse is quick enough, voltage could actually seep through the capacitor to the vcc at its off state and possibly trigger the output. So basically you would want to remove that capacitor so you can use it for PWM. You could cut the connection to the capacitor:
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