LM75B I2C temperature sensor
Dependencies: mbed
Diff: LM75B.cpp
- Revision:
- 0:00a546855093
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/LM75B.cpp Wed Feb 04 05:47:22 2015 +0000 @@ -0,0 +1,78 @@ +#include "mbed.h" +#include "stdint.h" +#include "LM75B.h" + +I2C i2c(p28,p27); // sda, scl +Serial pc(USBTX, USBRX); // tx, rx +char cmd[32]; +int i; +short T; + +void set_ch(char sel) +{ // PCA9541のサンプル + // MST_0側の自分にスレーブ側の制御権を得る場合 + cmd[0] = 1; // PCA9541 コマンドコード Cont Reg + i2c.write( 0xe2, cmd, 1); // Cont Regを指定 + i2c.read( 0xe2, cmd, 1); // Cont Regを読込み + wait(0.1); // 0.1s待つ + switch(cmd[0] & 0xf) + { + case 0: // bus off, has control + case 1: // bus off, no control + case 5: // bus on, no control + cmd[0] = 1; // PCA9541 コマンドコード Cont Reg + cmd[1] = 4; // bus on, has control + i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み + i2c.read( 0xe2, cmd, 1); // Cont Regを読込み + break; + case 2: // bus off, no control + case 3: // bus off, has control + case 6: // bus on, no control + cmd[0] = 1; // PCA9541 コマンドコード Cont Reg + cmd[1] = 5; // bus on, has control + i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み + i2c.read( 0xe2, cmd, 1); // Cont Regを読込み + break; + case 9: // bus on, no control + case 0xc: // bus on, no control + case 0xd: // bus off, no control + cmd[0] = 1; // PCA9541 コマンドコード Cont Reg + cmd[1] = 0; // bus on, has control + i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み + i2c.read( 0xe2, cmd, 1); // Cont Regを読込み + break; + case 0xa: // bus on, no control + case 0xe: // bus off, no control + case 0xf: // bus on, has control + cmd[0] = 1; // PCA9541 コマンドコード Cont Reg + cmd[1] = 1; // bus on, has control + i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み + i2c.read( 0xe2, cmd, 1); // Cont Regを読込み + break; + default: + break; + } + + cmd[0] = sel; // PCA9546 Cont Reg sel channel enabled + i2c.write( 0xe8, cmd, 1); // Send command string +} + +int main () +{ + i2c.frequency(100000); + pc.printf("LM75B Sample Program\r\n"); + set_ch(2); // LM75Bはch1に接続 + + // LM75B + while(1) + { + cmd[0] = Temp; + i2c.write(LM75_ADDR, cmd, 1, true); // pointer = Temp + i2c.read(LM75_ADDR, cmd, 2); // Read Temp register + T = (cmd[0]<<8) | cmd[1]; // calculate temperature + pc.printf("%.2f ℃\r\n", T / 256.0); + wait(2.0); + } +} + +