CQ_I2C_book / Mbed 2 deprecated LM75B

LM75B I2C temperature sensor

Dependencies:   mbed

LM75B.cpp@0:00a546855093, 2015-02-04 (annotated)

Committer:
wataaki
Date:
Wed Feb 04 05:47:22 2015 +0000
Revision:
0:00a546855093
initial version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wataaki 0:00a546855093 1 #include "mbed.h"
wataaki 0:00a546855093 2 #include "stdint.h"
wataaki 0:00a546855093 3 #include "LM75B.h"
wataaki 0:00a546855093 4
wataaki 0:00a546855093 5 I2C i2c(p28,p27); // sda, scl
wataaki 0:00a546855093 6 Serial pc(USBTX, USBRX); // tx, rx
wataaki 0:00a546855093 7 char cmd[32];
wataaki 0:00a546855093 8 int i;
wataaki 0:00a546855093 9 short T;
wataaki 0:00a546855093 10
wataaki 0:00a546855093 11 void set_ch(char sel)
wataaki 0:00a546855093 12 { // PCA9541のサンプル
wataaki 0:00a546855093 13 // MST_0側の自分にスレーブ側の制御権を得る場合
wataaki 0:00a546855093 14 cmd[0] = 1; // PCA9541 コマンドコード Cont Reg
wataaki 0:00a546855093 15 i2c.write( 0xe2, cmd, 1); // Cont Regを指定
wataaki 0:00a546855093 16 i2c.read( 0xe2, cmd, 1); // Cont Regを読込み
wataaki 0:00a546855093 17 wait(0.1); // 0.1s待つ
wataaki 0:00a546855093 18 switch(cmd[0] & 0xf)
wataaki 0:00a546855093 19 {
wataaki 0:00a546855093 20 case 0: // bus off, has control
wataaki 0:00a546855093 21 case 1: // bus off, no control
wataaki 0:00a546855093 22 case 5: // bus on, no control
wataaki 0:00a546855093 23 cmd[0] = 1; // PCA9541 コマンドコード Cont Reg
wataaki 0:00a546855093 24 cmd[1] = 4; // bus on, has control
wataaki 0:00a546855093 25 i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み
wataaki 0:00a546855093 26 i2c.read( 0xe2, cmd, 1); // Cont Regを読込み
wataaki 0:00a546855093 27 break;
wataaki 0:00a546855093 28 case 2: // bus off, no control
wataaki 0:00a546855093 29 case 3: // bus off, has control
wataaki 0:00a546855093 30 case 6: // bus on, no control
wataaki 0:00a546855093 31 cmd[0] = 1; // PCA9541 コマンドコード Cont Reg
wataaki 0:00a546855093 32 cmd[1] = 5; // bus on, has control
wataaki 0:00a546855093 33 i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み
wataaki 0:00a546855093 34 i2c.read( 0xe2, cmd, 1); // Cont Regを読込み
wataaki 0:00a546855093 35 break;
wataaki 0:00a546855093 36 case 9: // bus on, no control
wataaki 0:00a546855093 37 case 0xc: // bus on, no control
wataaki 0:00a546855093 38 case 0xd: // bus off, no control
wataaki 0:00a546855093 39 cmd[0] = 1; // PCA9541 コマンドコード Cont Reg
wataaki 0:00a546855093 40 cmd[1] = 0; // bus on, has control
wataaki 0:00a546855093 41 i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み
wataaki 0:00a546855093 42 i2c.read( 0xe2, cmd, 1); // Cont Regを読込み
wataaki 0:00a546855093 43 break;
wataaki 0:00a546855093 44 case 0xa: // bus on, no control
wataaki 0:00a546855093 45 case 0xe: // bus off, no control
wataaki 0:00a546855093 46 case 0xf: // bus on, has control
wataaki 0:00a546855093 47 cmd[0] = 1; // PCA9541 コマンドコード Cont Reg
wataaki 0:00a546855093 48 cmd[1] = 1; // bus on, has control
wataaki 0:00a546855093 49 i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み
wataaki 0:00a546855093 50 i2c.read( 0xe2, cmd, 1); // Cont Regを読込み
wataaki 0:00a546855093 51 break;
wataaki 0:00a546855093 52 default:
wataaki 0:00a546855093 53 break;
wataaki 0:00a546855093 54 }
wataaki 0:00a546855093 55
wataaki 0:00a546855093 56 cmd[0] = sel; // PCA9546 Cont Reg sel channel enabled
wataaki 0:00a546855093 57 i2c.write( 0xe8, cmd, 1); // Send command string
wataaki 0:00a546855093 58 }
wataaki 0:00a546855093 59
wataaki 0:00a546855093 60 int main ()
wataaki 0:00a546855093 61 {
wataaki 0:00a546855093 62 i2c.frequency(100000);
wataaki 0:00a546855093 63 pc.printf("LM75B Sample Program\r\n");
wataaki 0:00a546855093 64 set_ch(2); // LM75Bはch1に接続
wataaki 0:00a546855093 65
wataaki 0:00a546855093 66 // LM75B
wataaki 0:00a546855093 67 while(1)
wataaki 0:00a546855093 68 {
wataaki 0:00a546855093 69 cmd[0] = Temp;
wataaki 0:00a546855093 70 i2c.write(LM75_ADDR, cmd, 1, true); // pointer = Temp
wataaki 0:00a546855093 71 i2c.read(LM75_ADDR, cmd, 2); // Read Temp register
wataaki 0:00a546855093 72 T = (cmd[0]<<8) | cmd[1]; // calculate temperature
wataaki 0:00a546855093 73 pc.printf("%.2f ℃\r\n", T / 256.0);
wataaki 0:00a546855093 74 wait(2.0);
wataaki 0:00a546855093 75 }
wataaki 0:00a546855093 76 }
wataaki 0:00a546855093 77
wataaki 0:00a546855093 78