--- /dev/null
+/*
+* INA219 util - part of PowerCape by AndiceLabs
+*
+* Copyright (C) 2014 AndiceLabs admin@andicelabs.com http://andicelabs.com
+* Copyright (C) 2014 Zig Fisher flyrouter@gmail.com http://zftlab.org
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+*
+* Example run and output:
+*
+* OpenWRT:~# ina219 -b 0 -i 60
+*
+* 22:49 12168mV 134.2mA
+* 22:50 12168mV 239.9mA
+* 22:51 12168mV 134.7mA
+*
+*/
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <endian.h>
+#include <string.h>
+#include <time.h>
+#include <getopt.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <linux/i2c-dev.h>
+
+#define CONFIG_REG 0
+#define SHUNT_REG 1
+#define BUS_REG 2
+#define POWER_REG 3
+#define CURRENT_REG 4
+#define CALIBRATION_REG 5
+
+#define AVR_ADDRESS 0x21
+#define INA_ADDRESS 0x40
+
+typedef enum {
+ OP_DUMP,
+ OP_VOLTAGE,
+ OP_CURRENT,
+ OP_MONITOR,
+ OP_NONE
+} op_type;
+
+op_type operation = OP_DUMP;
+
+int interval = 60;
+int i2c_bus = 0;
+int i2c_address = INA_ADDRESS;
+int handle;
+int whole_numbers = 0;
+
+
+void msleep( int msecs )
+{
+ usleep( msecs * 1000 );
+}
+
+
+int i2c_read( void *buf, int len )
+{
+ int rc = 0;
+
+ if ( read( handle, buf, len ) != len )
+ {
+ printf( "I2C read failed: %s\n", strerror( errno ) );
+ rc = -1;
+ }
+
+ return rc;
+}
+
+
+int i2c_write( void *buf, int len )
+{
+ int rc = 0;
+
+ if ( write( handle, buf, len ) != len )
+ {
+ printf( "I2C write failed: %s\n", strerror( errno ) );
+ rc = -1;
+ }
+
+ return rc;
+}
+
+
+int register_read( unsigned char reg, unsigned short *data )
+{
+ int rc = -1;
+ unsigned char bite[ 4 ];
+
+ bite[ 0 ] = reg;
+ if ( i2c_write( bite, 1 ) == 0 )
+ {
+ if ( i2c_read( bite, 2 ) == 0 )
+ {
+ *data = ( bite[ 0 ] << 8 ) | bite[ 1 ];
+ rc = 0;
+ }
+ }
+
+ return rc;
+}
+
+
+int register_write( unsigned char reg, unsigned short data )
+{
+ int rc = -1;
+ unsigned char bite[ 4 ];
+
+ bite[ 0 ] = reg;
+ bite[ 1 ] = ( data >> 8 ) & 0xFF;
+ bite[ 2 ] = ( data & 0xFF );
+
+ if ( i2c_write( bite, 3 ) == 0 )
+ {
+ rc = 0;
+ }
+
+ return rc;
+}
+
+
+void show_usage( char *progname )
+{
+ fprintf( stderr, "Usage: %s <mode> \n", progname );
+ fprintf( stderr, " Mode (required):\n" );
+ fprintf( stderr, " -h --help Show usage.\n" );
+ fprintf( stderr, " -i --interval Set interval for monitor mode.\n" );
+ fprintf( stderr, " -w --whole Show whole numbers only. Useful for scripts.\n" );
+ fprintf( stderr, " -v --voltage Show battery voltage in mV.\n" );
+ fprintf( stderr, " -c --current Show battery current in mA.\n" );
+ fprintf( stderr, " -a --address <addr> Override I2C address of INA219 from default of 0x%02X.\n", i2c_address );
+ fprintf( stderr, " -b --bus <i2c bus> Override I2C bus from default of %d.\n", i2c_bus );
+ exit( 1 );
+}
+
+
+void parse( int argc, char *argv[] )
+{
+ while( 1 )
+ {
+ static const struct option lopts[] =
+ {
+ { "address", 0, 0, 'a' },
+ { "bus", 0, 0, 'b' },
+ { "current", 0, 0, 'c' },
+ { "help", 0, 0, 'h' },
+ { "interval", 0, 0, 'i' },
+ { "voltage", 0, 0, 'v' },
+ { "whole", 0, 0, 'w' },
+ { NULL, 0, 0, 0 },
+ };
+ int c;
+
+ c = getopt_long( argc, argv, "a:b:chi:vw", lopts, NULL );
+
+ if( c == -1 )
+ break;
+
+ switch( c )
+ {
+ case 'a':
+ {
+ errno = 0;
+ i2c_address = (int)strtol( optarg, NULL, 0 );
+ if ( errno != 0 )
+ {
+ fprintf( stderr, "Unknown address parameter %s.\n", optarg );
+ exit( 1 );
+ }
+ break;
+ }
+
+ case 'b':
+ {
+ errno = 0;
+ i2c_bus = (int)strtol( optarg, NULL, 0 );
+ if ( errno != 0 )
+ {
+ fprintf( stderr, "Unknown bus parameter %s.\n", optarg );
+ exit( 1 );
+ }
+ break;
+ }
+
+ case 'c':
+ {
+ operation = OP_CURRENT;
+ break;
+ }
+
+ default:
+ case 'h':
+ {
+ operation = OP_NONE;
+ show_usage( argv[ 0 ] );
+ break;
+ }
+
+ case 'i':
+ {
+ operation = OP_MONITOR;
+ interval = atoi( optarg );
+ if ( ( interval == 0 ) && ( errno != 0 ) )
+ {
+ fprintf( stderr, "Invalid interval value\n" );
+ exit( 1 );
+ }
+ break;
+ }
+
+ case 'v':
+ {
+ operation = OP_VOLTAGE;
+ break;
+ }
+
+ case 'w':
+ {
+ whole_numbers = 1;
+ break;
+ }
+ }
+ }
+}
+
+
+int get_voltage( float *mv )
+{
+ short bus;
+
+ if ( register_read( BUS_REG, (unsigned short*)&bus ) != 0 )
+ {
+ return -1;
+ }
+
+ *mv = ( float )( ( bus & 0xFFF8 ) >> 1 );
+ return 0;
+}
+
+
+int get_current( float *ma )
+{
+ short shunt;
+
+ if ( register_read( SHUNT_REG, &shunt ) != 0 )
+ {
+ return -1;
+ }
+
+ *ma = (float)shunt / 10;
+ return 0;
+}
+
+
+void show_current( void )
+{
+ float ma;
+
+ if ( get_current( &ma ) )
+ {
+ fprintf( stderr, "Error reading current\n" );
+ return;
+ }
+
+ if ( whole_numbers )
+ {
+ printf( "%4.0f\n", ma );
+ }
+ else
+ {
+ printf( "%04.1f\n", ma );
+ }
+}
+
+
+void show_voltage( void )
+{
+ float mv;
+
+ if ( get_voltage( &mv ) )
+ {
+ fprintf( stderr, "Error reading voltage\n" );
+ return;
+ }
+ printf( "%4.0f\n", mv );
+}
+
+
+void show_voltage_current( void )
+{
+ float mv, ma;
+
+ if ( get_current( &ma ) || get_voltage( &mv ) )
+ {
+ fprintf( stderr, "Error reading voltage/current\n" );
+ return;
+ }
+
+ if ( whole_numbers )
+ {
+ printf( "%04.0fmV %4.0fmA\n", mv, ma );
+ }
+ else
+ {
+ printf( "%04.0fmV %04.1fmA\n", mv, ma );
+ }
+ fflush(stdout);
+}
+
+
+void monitor( void )
+{
+ struct tm *tmptr;
+ time_t seconds;
+
+ while ( 1 )
+ {
+ seconds = time( NULL );
+ tmptr = localtime( &seconds );
+ printf( "%04d-%02d-%02dT%02d:%02d:%02d ",
+ tmptr->tm_year + 1900, tmptr->tm_mon +1, tmptr->tm_mday,
+ tmptr->tm_hour, tmptr->tm_min, tmptr->tm_sec );
+ show_voltage_current();
+ sleep( interval );
+ }
+}
+
+
+int main( int argc, char *argv[] )
+{
+ char filename[ 20 ];
+
+ parse( argc, argv );
+
+ snprintf( filename, 19, "/dev/i2c-%d", i2c_bus );
+ handle = open( filename, O_RDWR );
+ if ( handle < 0 )
+ {
+ fprintf( stderr, "Error opening bus %d: %s\n", i2c_bus, strerror( errno ) );
+ exit( 1 );
+ }
+
+ if ( ioctl( handle, I2C_SLAVE, i2c_address ) < 0 )
+ {
+ fprintf( stderr, "Error setting address %02X: %s\n", i2c_address, strerror( errno ) );
+ exit( 1 );
+ }
+
+ switch ( operation )
+ {
+ case OP_DUMP:
+ {
+ show_voltage_current();
+ break;
+ }
+
+ case OP_VOLTAGE:
+ {
+ show_voltage();
+ break;
+ }
+
+ case OP_CURRENT:
+ {
+ show_current();
+ break;
+ }
+
+ case OP_MONITOR:
+ {
+ monitor();
+ break;
+ }
+
+ default:
+ case OP_NONE:
+ {
+ break;
+ }
+ }
+
+ close( handle );
+ return 0;
+}
+