I just need to know if there will be enough 'space' between them to be able to differentiate.
There should be plenty of "space" between them. Make the circuit and use a meter to measure the output voltage at your 3 points. Now with a uC or ADC (whatever you choose) note the bit count at the three levels. Even a common 10 bit ADC will give 1024 quantization levels. Just note the analog channel inputs at your three levels of dark to light.Of course surplus parts are cheaper at the loss of the part number and datasheet. I will get the bright light resistance and be back.
The advantage to the ADC and microcontroller as part of the system, is that I can set the thresholds between dark-shade and shade-light.
Solar hot water heating. Black is as good an absorber as it is radiator. So you don't want to pump water to the panels when they are not collecting heat and that includes when in shade. In a linear array, two are needed to ensure the entire panel is in sun. These are in a grid so there needs to be one in between. 1-2 for the top row and 2-3 for the bottom row. The panels are 8 feet square, plus distance to the controller, puts it way over the I2C range. Many low to mid range manufacturers skip on this. Mid-range may have an option. High end panels have it built into their panels.
Just FYI,
Already there in order to know when to shift from re-circulation to supply/return. With no recirculation, the temperature sensors are in stagnant area waiting for convection to warm them. Also when changing from sun to shade, the heat does not immediately die off. The water in the collector is still above the supply as well as there being heat in the collector. No sense stopping until you are out of gas.
That's slick. I saw one as a module on Amazon. Think for a little over two bucks each I'll ask my wife to add some to her next Amazon order.
#include <Wire.h>
#define BYTES2READ (2)
#define BH1750addr (0x23) /* slave I2c address */
/* globals */
int status;
void setup() {
Wire.begin();
Serial.begin(9600);
Serial.println("BH1750 sensor test");
status = initBH1750();
if (status) {
Serial.print("Error ");
Serial.print(status);
Serial.println("Could not write BH1750 mode");
}
}
void loop() {
byte BHlxdata[2]; /* data read from the sensor */
unsigned int lux; /* converted lux value */
/* read the sensor data */
Wire.requestFrom(BH1750addr,BYTES2READ);
BHlxdata[0] = (byte)Wire.read();
BHlxdata[1] = (byte)Wire.read();
/* translate the data */
lux = ( (BHlxdata[0] << 8) | BHlxdata[1]) / 1.2;
Serial.print(lux);
Serial.println(" lux");
/* wait 120 ms before the next read as per BH1750 data sheet */
delay(120);
/* delay for the loop print - change as desired */
delay(1500);
}
int initBH1750()
{
byte BHmodedata = 0x10; /* BH1750 initialization code for 1 lux resolution */
Wire.beginTransmission(BH1750addr);
Wire.write(BHmodedata);
if ( (status = Wire.endTransmission() ) ) {
Serial.print("Error ");
Serial.print(status);
Serial.println("Could not write BH1750 mode");
}
delay(180); /* 180 ms delay as per BH1750 data sheet */
return (status);
}Want to thank you for sharing that. I loaded the code which went fine. Tomorrow my wife will order some modules. The code loaded just fine so no reason to believe it won't work. Thanks again....Kart31 I hope you can excuse a little thread drift...
Yeah, they are real easy to use. Here is some Arduweenie sample code (if I copied the right file):
Code:#include <Wire.h> #define BYTES2READ (2) #define BH1750addr (0x23) /* slave I2c address */ /* globals */ int status; void setup() { Wire.begin(); Serial.begin(9600); Serial.println("BH1750 sensor test"); status = initBH1750(); if (status) { Serial.print("Error "); Serial.print(status); Serial.println("Could not write BH1750 mode"); } } void loop() { byte BHlxdata[2]; /* data read from the sensor */ byte lux; /* converted lux value */ /* read the sensor data */ Wire.requestFrom(BH1750addr, 2); BHlxdata[0] = (byte)Wire.read(); BHlxdata[1] = (byte)Wire.read(); /* translate the data */ lux = ((BHlxdata[0] << 8) | BHlxdata[1]) / 1.2; Serial.print(lux); Serial.println(" lux"); /* wait 120 ms before the next read as per BH1750 data sheet */ delay(120); /* delay for the loop print - change as desired */ delay(1500); } byte initBH1750() { byte BHmodedata = 0x10; /* BH1750 initialization code for 1 lux resolution */ Wire.beginTransmission(BH1750addr); Wire.write(BHmodedata); if ( (status = Wire.endTransmission() ) ) { Serial.print("Error "); Serial.print(status); Serial.println("Could not write BH1750 mode"); } delay(180); /* 180 ms delay as per BH1750 data sheet */ return (status); }
About 5 years ago, I used one to figure out the resistors to use (to aim for equal intensity) on an RGB led for a color mixer using a pic 12F1572. Was not smart enough to do it with math so I did it like this:
View attachment 122672
I used the values shown on the dashed horizontal for the respective R-G-B elements. Empirically, it worked and I was real proud of myself. After about 10 minutes of staring, I started to see spots and was less proud
You arer welcome. Note, I had to update the code (I edited the post) The first one was an earlier version in which I mis-declared a variable (you would think that I would have just deleted it - geez). I just tested this - even dug up the module. BTW: On mine, if you connect ADDR to +5v it changes the address from 0x23 to 0x5c.
On my ADS1115 (16 BIT A/D) about the same. Jumper ADDR to any of several other lines changes the address. Thanks for the update and wife ordered me a few modules this morning.
| Illuminance | Example |
|---|---|
| 120,000 lux | Brightest sunlight |
| 111,000 lux | Bright sunlight |
| 109,870 lux | AM 1.5 global solar spectrum sunlight |
| 20,000 lux | Shade illuminated by entire clear blue sky, midday |
| 1,000 - 2,000 lux | Typical overcast day, midday |
| <200 lux | Extreme of thickest storm clouds, midday |
| 400 lux | Sunrise or sunset on a clear day (ambient illumination) |
| 40 lux | Fully overcast, sunset/sunrise |
| <1 lux | Extreme of thickest storm clouds, sunset/rise |
