Max Stenham / INA219

Library for INA219 current sensor

INA219.cpp@0:a576b66395ed, 2016-10-19 (annotated)

Committer:
maximusismax
Date:
Wed Oct 19 10:19:57 2016 +0000
Revision:
0:a576b66395ed
INA219 Library (Author: Jack Cosslett)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
maximusismax 0:a576b66395ed 1 #include "INA219.h"
maximusismax 0:a576b66395ed 2
maximusismax 0:a576b66395ed 3 INA219::INA219(I2C& theI2C, char address)
maximusismax 0:a576b66395ed 4 :i2c(theI2C), i2cAddress(address)
maximusismax 0:a576b66395ed 5 {
maximusismax 0:a576b66395ed 6 init();
maximusismax 0:a576b66395ed 7 }
maximusismax 0:a576b66395ed 8
maximusismax 0:a576b66395ed 9 void INA219::init()
maximusismax 0:a576b66395ed 10 {
maximusismax 0:a576b66395ed 11 //set up config register //256 averages //continuous shunt voltage conversion
maximusismax 0:a576b66395ed 12 short write_byte = CONF_DEFAULT & ~_BV(BRNG);
maximusismax 0:a576b66395ed 13
maximusismax 0:a576b66395ed 14 write(REG_CONF, write_byte);
maximusismax 0:a576b66395ed 15 //set up calibration (full range ~5A)
maximusismax 0:a576b66395ed 16 write(REG_CAL, 0x14F7);
maximusismax 0:a576b66395ed 17 }
maximusismax 0:a576b66395ed 18
maximusismax 0:a576b66395ed 19 void INA219::write(INA219REG reg, short value)
maximusismax 0:a576b66395ed 20 {
maximusismax 0:a576b66395ed 21 shortToChar stc;
maximusismax 0:a576b66395ed 22 char cmd[3];
maximusismax 0:a576b66395ed 23 stc.u16 = value;
maximusismax 0:a576b66395ed 24
maximusismax 0:a576b66395ed 25 cmd[0] = reg;
maximusismax 0:a576b66395ed 26 cmd[1] = stc.u8[1];
maximusismax 0:a576b66395ed 27 cmd[2] = stc.u8[0];
maximusismax 0:a576b66395ed 28
maximusismax 0:a576b66395ed 29 i2c.write(i2cAddress,cmd,3);
maximusismax 0:a576b66395ed 30 }
maximusismax 0:a576b66395ed 31
maximusismax 0:a576b66395ed 32 short INA219::read(INA219REG reg)
maximusismax 0:a576b66395ed 33 {
maximusismax 0:a576b66395ed 34 shortToChar stc;
maximusismax 0:a576b66395ed 35
maximusismax 0:a576b66395ed 36 char cmd[2];
maximusismax 0:a576b66395ed 37 cmd[0] = reg;
maximusismax 0:a576b66395ed 38 i2c.write(i2cAddress,cmd,1);
maximusismax 0:a576b66395ed 39
maximusismax 0:a576b66395ed 40 i2c.read(i2cAddress, cmd, 2);
maximusismax 0:a576b66395ed 41 stc.u8[1] = cmd[0];
maximusismax 0:a576b66395ed 42 stc.u8[0] = cmd[1];
maximusismax 0:a576b66395ed 43
maximusismax 0:a576b66395ed 44 return (stc.u16);
maximusismax 0:a576b66395ed 45 }
maximusismax 0:a576b66395ed 46
maximusismax 0:a576b66395ed 47 float INA219::getCurrent()
maximusismax 0:a576b66395ed 48 {
maximusismax 0:a576b66395ed 49 short curr = read(REG_CURR);
maximusismax 0:a576b66395ed 50 return (float)curr / 6554;
maximusismax 0:a576b66395ed 51 }