Lib to read the MCP9808 over Initialized I2C bus
Diff: MCP9808.cpp
- Revision:
- 0:46326feade89
diff -r 000000000000 -r 46326feade89 MCP9808.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MCP9808.cpp Tue Apr 12 09:02:48 2016 +0000 @@ -0,0 +1,60 @@ +#include "MCP9808.h" + +//***********************************/************************************ +// Constant // +//***********************************/************************************ +#define MCP9808_I2C_ADDR 0x30 //( 18<<1) + +#define MCP9808_REG_CONFIG 0x01 +#define MCP9808_REG_TUPPER 0x02 +#define MCP9808_REG_TLOWER 0x03 +#define MCP9808_REG_TCRIT 0x04 +#define MCP9808_REG_TAMB 0x05 +#define MCP9808_REG_MANID 0x06 +#define MCP9808_REG_DEVID 0x07 +#define MCP9808_REG_RESOL 0x08 + +#define MCP9808_TAMB_MASK 0x0F +#define MCP9808_SIGN_POS 0x03 + +//***********************************/************************************ +// Constructors // +//***********************************/************************************ +MCP9808::MCP9808(I2C *i2c, bool a0, bool a1, bool a2):_i2c(i2c) +{ + _addr = (MCP9808_I2C_ADDR | (a2<<3) | (a1<<2) | (a0<<1)); +} + +float MCP9808::getTemp(void) +{ + char reg = MCP9808_REG_TAMB; + float ta; + char buf[2]; + + _i2c->write(_addr, ®, 1); + _i2c->read(_addr, buf, 2); + + /* + if(buf[0] & (1<<MCP9808_SIGN_POS)) + { + buf[0] &= MCP9808_TAMB_MASK; + + ta = 256 - (buf[0]*16 + buf[1]*0.0625); + } + else + { + buf[0] &= MCP9808_TAMB_MASK; + ta = (buf[0]*16 + buf[1]*0.0625); + }*/ + + ta = ((buf[0]&MCP9808_TAMB_MASK) << 8) | buf[1]; + ta /= 16.0; + + if(buf[0] & (1<<MCP9808_SIGN_POS)) + { + ta -= 256; + } + + return ta; +} +