From 66af3d0672fc085d999d5432d110a674e0b9f35b Mon Sep 17 00:00:00 2001
From: "R.P.Clark" <robin@scientificdatasystems.co.uk>
Date: Mon, 18 Sep 2023 16:56:45 +0100
Subject: [PATCH] utility for hedgehog image

---
 Makefile   |  2 ++
 hedgehog.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100644 hedgehog.c

diff --git a/Makefile b/Makefile
index 7534cf2..e64594a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,2 +1,4 @@
 all:
 	gcc -O2 -std=gnu99 -Wall -Wextra main.c bme680.c i2c.c -o bme680
+hedgehog:
+	gcc -O2 -std=gnu99 -Wall -Wextra hedgehog.c bme680.c i2c.c -o hedgehog
diff --git a/hedgehog.c b/hedgehog.c
new file mode 100644
index 0000000..461c93f
--- /dev/null
+++ b/hedgehog.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include "bme680.h"
+#include "i2c.h"
+#include <unistd.h>
+
+#define DEVICE "/dev/i2c-1"
+#define ADDRESS 0x77
+
+int main(){
+	
+	int fd = i2c_init(DEVICE, ADDRESS);
+	bme680_t bme680;
+
+	//printf("%X\n", i2c_read_reg2(fd, 0xD0));
+	if (bme680_calibrate(fd, &bme680.cal) != 0) {
+	       fprintf(stderr, "error bme680 calibration\n");
+	} else {
+ 		//print_calibration(&bme680.cal);
+	}		
+
+
+
+	//1. write osrs fields to diff regs
+	uint8_t ctrl_meas, ctrl_hum;
+
+	uint8_t osrs_t, osrs_p, osrs_h, ctrl_mode;
+	osrs_t = osrs_p = osrs_h = 0b110;
+	ctrl_mode = 0;
+
+	ctrl_meas = (osrs_t << 5) | (osrs_p << 2) | ctrl_mode;
+	ctrl_hum = osrs_h;
+
+	i2c_write_reg(fd, 0x74, ctrl_meas);
+	i2c_write_reg(fd, 0x72, ctrl_hum);
+
+	// set filter mode 
+	
+	uint8_t filter_reg = 0b101 << 2;
+	i2c_write_reg(fd, 0x75, filter_reg);
+	
+	// todo gas stuff
+	
+	// resend ctrl_meas but with ctrl_mode set to 0b01 in it, then it should work
+	ctrl_meas |= 1;
+	i2c_write_reg(fd,  0x74, ctrl_meas);
+
+	// poll reg `meas_status_0 bit 5. It will be 0 when all scheduled conversions are done.
+	uint8_t qq;
+	while ((qq = i2c_read_reg2(fd, 0x1D)) >> 4) {
+		usleep(2000); // 2 ms
+	}
+
+	// now read the temp/press/hum adc and convert in order.
+	uint32_t temp_adc, press_adc, hum_adc;
+
+
+	uint8_t buffer[3];
+
+	i2c_read_reg(fd, 0x22, 3, buffer);
+	temp_adc = (buffer[0] << 12) | (buffer[1] << 4) | (buffer[2] >> 4);
+
+	i2c_read_reg(fd, 0x1F, 3, buffer);
+	press_adc = (buffer[0] << 12) | (buffer[1] << 4) | (buffer[2] >> 4);
+
+	i2c_read_reg(fd, 0x25, 2, buffer);
+	hum_adc = (buffer[0] << 8) | buffer[1];
+
+	// adc readings are only 20-bit when the IIR filter is enabled, otherwise
+	// the size depends on the oversample settings (osrs_X).
+	
+	double temperature = calc_temp_comp_1 ( temp_adc ,  &bme680 );
+	
+	double pressure = calc_press_comp_1 ( press_adc  , &bme680 );
+
+	double humidity = calc_hum_comp_1 ( hum_adc, &bme680 );
+
+	if (humidity > 100.0) humidity = 100.0;
+	if (humidity < 0.0) humidity = 0.0;
+
+	printf("%.1lfoC    %.2lf hPa    %.1lf %%RH\n", temperature, pressure/100, humidity);
+
+	close(fd);
+	return 0;
+}