INA226 module

### Chip characteristics
1. **Measurement voltage range: 0~36V**
2. INA226 maximum acquisition stable shunt voltage: 81.92mV
3. The measurement current range depends on the resistance of the voltage dividing resistor and the maximum voltage dividing. Generally speaking, the smaller the voltage dividing resistor is, the larger the measurement current range is. For example, when using a 0.1R voltage dividing resistor, the maximum measured current is 817.2mA
4. The default shunt resistor is 5mΩ, and the maximum current that can be collected: 81.92mV/5mΩ = 16.384A
5. Chip working voltage: 2.7V~5.5V
6. Default IIC address: 0x40
### Working principle
INA makes two measurements during operation: shunt voltage and bus voltage, and then converts these measured values ​​into current according to the calibration register value to calculate power.
INA226 is a high-precision current and voltage monitor that can measure the voltage difference (Vsense) between VBUS and VIN.
The VBUS pin is used to measure the bus voltage and can be connected in the range of **0~36V**.
The VIN+ and VIN- pins are used to measure the voltage across the shunt resistor. The voltage difference between them cannot exceed **±81.92mV**.
**It will work if the VBUS pin is connected to VIN+ or VIN-, but it will be more accurate to connect it to VIN- because it can eliminate the common mode interference at both ends of the shunt resistor.
### Alert Pin
INA226 has an alarm limit register (07h), which allows the alarm pin to be programmed. **The Alert pin is an open-drain output and requires a pull-up resistor** when used. Any one of 5 alarm functions available:
1. Shunt Voltage Over-Limit (SOL)
2. Shunt Voltage Under-Limit (SUL)
3. Bus Voltage Over-Limit (BOL)
4. Bus Voltage Under-Limit (BUL)
5. Power Over-Limit (POL)
### Test program```C
++
//INA226 library: https://github.com/RobTillaart/INA226

#include "INA226.h"
#include "Wire.h"

INA226 INA (0x40); //I2C address
//INA226 INA(0x44);

//Voltage and current sampling
void VA(){
float V = INA.getBusVoltage(); //VBUS voltage V
float mA = INA.getCurrent_mA(); / /Sampling resistor current mA
float mW = INA.getPower_mW(); //Power
float mV = INA.getShuntVoltage_mV(); //Sampling resistor voltage division
Serial.print( V); Serial.print(" V ");
Serial. print(mA); Serial.print(" mA ");
Serial.print(mW); Serial.print(" mW ");
Serial.print(mV); Serial.print(" mV ");
Serial.println( );
}

//Voltage and current sampling 2
void VA2(){
float V = INA.getBusVoltage(); //VBUS voltage V
float mV = INA.getShuntVoltage_mV(); //Sampling resistor voltage divider
float A = mV/10; //Sampling resistor voltage division/sampling resistor value = current
Serial.print( V); Serial.print(" V ");
Serial.print(mV); Serial.print(" mV ");
Serial.print( A, 4); Serial.print(" A ");
Serial.println();
}
void VA3()
{
float V = INA.getBusVoltage();
float I = INA.getCurrent();
float P = INA.getPower() ;
Serial.print(V);
Serial.print(" V ");
Serial.print(I);
Serial.print(" A ");
Serial.print(P);
Serial.print(" w ");
Serial .println();
}

void setup(){
Serial.begin(115200);
Wire.begin();
INA.setMaxCurrentShunt(8, 0.01); //Maximum current A,Shunt resistance value R
}

void loop(){
VA3();
delay(1000);
}

```