#include <bcm2835.h>
#include <stdint.h>
#include <stdio.h>

void init() {
	bcm2835_init();
	bcm2835_i2c_begin();
	bcm2835_i2c_set_baudrate(10000); /* 10 kHz */
	bcm2835_i2c_setSlaveAddress(0xB8);
}

void end() {
	bcm2835_i2c_end();
	bcm2835_close();
}

int readData(char buf[4]) {
	const static char cmd[3] = "\x03\x00\x04";
	char response[7];

	for(int i = 0; i < 7; i++) {
		response[i] = 0xFF;
	}
	
	printf("%d ", bcm2835_i2c_write(cmd, 3));
	printf("%d ", bcm2835_i2c_write(cmd, 3));
	printf("%d\n", bcm2835_i2c_read(response, 1));

	for(int i = 0; i < 7; i++) {
		printf("%02x ", response[i]);
	}
	printf("\n");
	
	if(response[0] != 0x03 ||
	   response[1] != 0x04) {
		return 0;
	} else {
		buf[0] = response[2];
		buf[1] = response[3];
		buf[2] = response[4];
		buf[3] = response[5];
	}

	return 1;
}

int main(int argc, char **argv) {
	char data[4];

	init();
	
	for(int i = 0; i < 10; i++) {
		if(!readData(data)) {
			continue;
		}
		int32_t rh = data[0] << 8 | data[1],
			    tm = data[2] << 8 | data[3];

		if(tm & (1<<15)) {
			tm = -(tm^~(1<<15));
		}

		printf("%02x %02x %02x %02x\n", data[0], data[1], data[2], data[3]);
		printf("%d %d\n", rh, tm);
	}

	end();
}