lm75.c

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00001 
00039 #include "lm75.h"
00040 
00041 #include "hw/hw_lm75.h"
00042 
00043 #include "cfg/cfg_lm75.h"
00044 
00045 #include <cfg/debug.h>
00046 #include <cfg/module.h>
00047 
00048 // Define logging setting (for cfg/log.h module).
00049 #define LOG_LEVEL   LM75_LOG_LEVEL
00050 #define LOG_FORMAT  LM75_LOG_FORMAT
00051 
00052 #include <cfg/log.h>
00053 
00054 #include <drv/i2c.h>
00055 #include <drv/ntc.h> // Macro and data type to manage celsius degree
00056 
00057 #define SELECT_ADDRESS(addr)   LM75_ADDRESS_BYTE | (addr << 1)
00058 #define LM75_ADDRESS_BYTE    0x91
00059 #define LM75_PAD_BYTE        0x0
00060 
00061 
00062 #if !CONFIG_I2C_DISABLE_OLD_API
00063 
00064 deg_t lm75_read_1(uint8_t sens_addr)
00065 {
00066     return lm75_read_2(&local_i2c_old_api, sens_addr);
00067 }
00068 #endif /* !CONFIG_I2C_DISABLE_OLD_API */
00069 
00070 
00071 /*
00072  * New API
00073  */
00074 deg_t lm75_read_2(I2c *i2c, uint8_t sens_addr)
00075 {
00076     uint8_t data[2];
00077     int16_t degree;
00078     int16_t deci_degree;
00079 
00080     i2c_start_w(i2c, SELECT_ADDRESS(sens_addr), 1, I2C_NOSTOP);
00081     i2c_putc(i2c, LM75_PAD_BYTE);
00082     i2c_start_r(i2c, SELECT_ADDRESS(sens_addr), sizeof(data), I2C_STOP);
00083     i2c_read(i2c, data, sizeof(data));
00084 
00085     if (i2c_error(i2c))
00086         return EOF;
00087 
00088     degree = (int16_t)data[0];
00089     deci_degree = (int16_t)(((data[1] >> 7) & 1 ) * 5);
00090 
00091     LOG_INFO("[%d.%d C]\n", degree, deci_degree);
00092 
00093     return degree * 10 + deci_degree;
00094 }