LM75B I2C temperature sensor
Dependencies: mbed
LM75B.cpp
- Committer:
- wataaki
- Date:
- 2015-02-04
- Revision:
- 0:00a546855093
File content as of revision 0:00a546855093:
#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); } }