Web based solar panel monitoring/managment

Testing some code to read the voltage divider and convert the A/D read to a voltage.

The 4.092  will need to be adjusted based on your resistors and tolerances.

This pix shows the web board, but the sample code is just testing the voltage divider.. I found the w5100 introduces  resistance on pin A2,3,4,5 requiring some code tweeks. Also A0/A1 are not usable  without modes the the network module since those pins are used for SD card control. 

/*

Read voltage divider module.

Gary Sanders (N8EMR)

ohgary@gmail.com

*/

int volt_pin=5;

void setup() {

Serial.begin(9600); // initialize serial communications for debugging.

}

void loop() {

float voltage;

float l_volt;

l_volt=analogRead(volt_pin);

voltage=(l_volt/4.092)/10;

Serial.print(voltage);

Serial.println("V ");

delay(1000);

}

Here is a sketch to read the acs715 module and print the current going through the module. NOTE: the module is directional in nature. If your getting odd readings flip the connections on the acs715 module. I am not trying to lab grade current measurements, just get a  reasonable look at current being used.  If you need more  accurate reading you might consider looping through the current read several times and averaging your results.

/*

Read http://www.pololu.com/ acs715 30amp 30v current modules

and serial print the value.

Gary (N8EMR)

ohgary@gmail.com

*/

float current_input_pin = A4;            // Analog input pin that the carrier board OUT is connected to

float current_input_value = 0;          // value read from the carrier boar

float amps = 0;

void setup() {

Serial.begin(9600); // initialize serial communications for debugging.

}

void loop() {

current_input_value = analogRead(current_input_pin);

amps = float ((((long)current_input_value * 5000 / 1024) - 500 ) * 1000 / 133)/1000;

if (amps < 0 )

amps = 0 ; // Get rid of sensor noise when current is at/near zero.

Serial.print(amps);

Serial.print("A ");

Serial.println("");

delay(1000);

}

Here is the test setup for  the voltage testing. A simple voltage divider network and  sketch to look at an analog pin.

Testing the pololu.com current module and sketches. Using a calibrated volt/amp meter to validate my readings.

Getting the basic hardware setup to do some testing of the voltage modules and the ethernet shield.