Using gattlib to read values from victron smart shunt bluetooth

testshunt.c

/*
clang++ -Wall -o testshunt testshunt.c /usr/lib/libgattlib.so 
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#include "gattlib.h"

volatile bool g_operation_completed;


/* 
As Documented at 
  https://community.victronenergy.com/questions/93919/victron-bluetooth-ble-protocol-publication.html
*/

const char* uuid_str_SOC 	= "65970fff-4bda-4c1e-af4b-551c4cf74769";
const char* uuid_str_V 		= "6597ed8d-4bda-4c1e-af4b-551c4cf74769";
const char* uuid_str_A 		= "6597ed8c-4bda-4c1e-af4b-551c4cf74769";
const char* uuid_str_P 		= "6597ed8e-4bda-4c1e-af4b-551c4cf74769";
const char* uuid_str_Consumed	= "6597eeff-4bda-4c1e-af4b-551c4cf74769";
const char* uuid_str_tempK	= "6597edec-4bda-4c1e-af4b-551c4cf74769";
const char* uuid_str_t2go	= "65970ffe-4bda-4c1e-af4b-551c4cf74769";

#define MINS_PER_HOUR ((int16_t)(60 ))
#define MINS_PER_DAY  ((int16_t)(MINS_PER_HOUR * 24 ))


static  void breakDuration(int16_t minutesIn, 
		int16_t *days, int16_t *hours, int16_t *mins ){

	uint16_t remainingMinutes = minutesIn;
		
	*days =  (remainingMinutes/ MINS_PER_DAY);
	remainingMinutes = minutesIn - (*days * MINS_PER_DAY);

	*hours =  (remainingMinutes / MINS_PER_HOUR) ;
	remainingMinutes = minutesIn -  ( (*days * MINS_PER_DAY) + (*hours * MINS_PER_HOUR));
	
	*mins = remainingMinutes;
}


static void connect_cb(gatt_connection_t* connection,  void* user_data) {
	if (connection != NULL) {
 		
		 uuid_t uuid;
 		int err = GATTLIB_SUCCESS;

		 printf("Connected \n");

// get SOC
		 if ( gattlib_string_to_uuid(uuid_str_SOC, strlen(uuid_str_SOC) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){
				int16_t i = (buffer[1] << 8) | buffer[0];
				double val = (double) (i) / 100.0;
				printf("\t%-10s: %0.2f%%\n", "SOC", val);
				free(buffer);
			}
		 }

// Get Battery Voltage
	 if ( gattlib_string_to_uuid(uuid_str_V, strlen(uuid_str_V) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){
				int16_t i = (buffer[1] << 8) | buffer[0];
				double val = (double) (i) / 100.0;
				printf("\t%-10s: %0.2fV\n", "Voltage", val);
				free(buffer);
			}
		 }

// Get Battery Current
	 if ( gattlib_string_to_uuid(uuid_str_A, strlen(uuid_str_A) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){
				uint16_t i = (buffer[1] << 8) | buffer[0];
				double val = (double) (i) / 1000.0;
				printf("\t%-10s: %0.2fA\n", "Current", val);
				free(buffer);
			}
		 }

// Get Battery Power
	 if ( gattlib_string_to_uuid(uuid_str_P, strlen(uuid_str_P) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){
				int16_t i = (buffer[1] << 8) | buffer[0];
				double val = (double) (i);
				printf("\t%-10s: %0.2fW\n", "Power", val);
				free(buffer);
			}
		 }
		 // Consumed Ah
	 if ( gattlib_string_to_uuid(uuid_str_Consumed, strlen(uuid_str_Consumed) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){
				int16_t i = (buffer[1] << 8) | buffer[0];
				double val = (double) (i) / 10.0;
					printf("\t%-10s: %0.2fAh\n", "Consumed", val);
				free(buffer);
			}
		 }

// Time remaining
	 if ( gattlib_string_to_uuid(uuid_str_t2go, strlen(uuid_str_t2go) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){

				int16_t i = (buffer[1] << 8) | buffer[0];
				if(i == -1)
					printf("\t%-10s: %s\n", "Time 2 Go", "Infinite");
				else 
				{ 
					int16_t  days, hours, mins;

					breakDuration(i, &days, &hours, &mins);
					//printf("%02x %02x  " , buffer[0],buffer[1]);

					printf("\t%-10s: ","Time 2 Go");
					if(days > 0) printf("%d Days ",days);
					if(hours > 0) printf("%d Hours ", hours);
					 printf("%d Mins ", mins);
					 printf("\n");
			}
				free(buffer);
			}
		 }

	 // Temperaure in Kelvin Ah
	 if ( gattlib_string_to_uuid(uuid_str_tempK, strlen(uuid_str_tempK) + 1, &uuid) == 0){
			 size_t len;
			 uint8_t *buffer = NULL;

			err =  gattlib_read_char_by_uuid(connection, &uuid, (void **)&buffer, &len);
			if(err == GATTLIB_SUCCESS){
				int16_t i = (buffer[1] << 8) | buffer[0];
				double val = (double) (i) / 100.0;
				val = (val - 273.15)* 1.8000 + 32.00;
				printf("\t%-10s: %0.2f°F\n", "Bat Temp", val);
				free(buffer);
			}
		 }
 


    }

		g_operation_completed = true;
}

int main(int argc, char *arg[]) {
	gatt_connection_t* con;

    const char* deviceID = "CA:9C:B9:8D:E3:70";

 	g_operation_completed = false;

 	con = gattlib_connect_async(NULL, deviceID, BDADDR_LE_RANDOM,  connect_cb, 0);
	if (con == NULL) {
			fprintf(stderr, "Fail to connect to the bluetooth device %s.\n",deviceID);
			return 1;
		} else {
			while (!g_operation_completed);
			gattlib_disconnect(con);
			printf("Disconnected \n");
		}
    return 0;
}