Buelmann: new implementation for ceiling Since my first functional fix in the ceiling computation in commit ceecabfddb57, I noticed that the computation used a linear search, that became rather computational expensive after that commit. The simple question is: why not a binary search? So, this commit implements the binary search. But there is a long story attached to this. Comparing ceiling results from hwOS and this OSTC4 code were very different. Basically, the original OSTC4 algorithm computed the ceiling using the same GFlow to GFhigh slope, in such a way, that the ceiling was in sync with the presented deco stops, where the hwOS code presents a GFhigh based ceiling. This said, it is more logical when the OSTC4 and hwOS code give similar results. This new recursive algorithm gives very similar results for the ceiling compared to hwOS. To be complete here, the Buelmann ceiling is the depth to which you can ascend, so that the leading tissue reaches GFhigh. This also explains why the deepest deco stop is normally deeper than the ceiling (unless one dives with GF like 80/80). The code implemented here is rather straightforward recursion. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>

/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef PRESSURE_H
#define PRESSURE_H

#include <stdint.h>

uint8_t init_pressure(void);
uint8_t pressure_update(void);

uint8_t is_init_pressure_done(void);

void  pressure_sensor_get_pressure_raw(void);
void  pressure_sensor_get_temperature_raw(void);
void pressure_calculation(void);

float get_temperature(void);
float get_pressure_mbar(void);
float get_surface_mbar(void);

void init_surface_ring(void);
void update_surface_pressure(uint8_t call_rhythm_seconds);

uint32_t demo_modify_temperature_and_pressure(int32_t divetime_in_seconds, uint8_t subseconds, float ceiling_mbar);

#endif /* PRESSURE_H */