I2C-bus master selector with interrupt logic and reset
Dependencies: mbed
PCA9541A.cpp@0:62f897b8acfa, 2015-02-04 (annotated)
- Committer:
- wataaki
- Date:
- Wed Feb 04 06:01:04 2015 +0000
- Revision:
- 0:62f897b8acfa
initial version
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
wataaki | 0:62f897b8acfa | 1 | #include "mbed.h" |
wataaki | 0:62f897b8acfa | 2 | |
wataaki | 0:62f897b8acfa | 3 | I2C i2c(p28,p27); // sda, scl |
wataaki | 0:62f897b8acfa | 4 | Serial pc(USBTX, USBRX); // tx, rx |
wataaki | 0:62f897b8acfa | 5 | char cmd[32]; |
wataaki | 0:62f897b8acfa | 6 | int i, j, k; |
wataaki | 0:62f897b8acfa | 7 | int sw; |
wataaki | 0:62f897b8acfa | 8 | |
wataaki | 0:62f897b8acfa | 9 | void set_ch(char sel) |
wataaki | 0:62f897b8acfa | 10 | { // PCA9541のサンプル |
wataaki | 0:62f897b8acfa | 11 | // MST_0側の自分にスレーブ側の制御権を得る場合 |
wataaki | 0:62f897b8acfa | 12 | cmd[0] = 1; // PCA9541 コマンドコード Cont Reg |
wataaki | 0:62f897b8acfa | 13 | i2c.write( 0xe2, cmd, 1); // Cont Regを指定 |
wataaki | 0:62f897b8acfa | 14 | i2c.read( 0xe2, cmd, 1); // Cont Regを読込み |
wataaki | 0:62f897b8acfa | 15 | wait(0.1); // 0.1s待つ |
wataaki | 0:62f897b8acfa | 16 | switch(cmd[0] & 0xf) |
wataaki | 0:62f897b8acfa | 17 | { |
wataaki | 0:62f897b8acfa | 18 | case 0: // bus off, has control |
wataaki | 0:62f897b8acfa | 19 | case 1: // bus off, no control |
wataaki | 0:62f897b8acfa | 20 | case 5: // bus on, no control |
wataaki | 0:62f897b8acfa | 21 | cmd[0] = 1; // PCA9541 コマンドコード Cont Reg |
wataaki | 0:62f897b8acfa | 22 | cmd[1] = 4; // bus on, has control |
wataaki | 0:62f897b8acfa | 23 | i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み |
wataaki | 0:62f897b8acfa | 24 | i2c.read( 0xe2, cmd, 1); // Cont Regを読込み |
wataaki | 0:62f897b8acfa | 25 | break; |
wataaki | 0:62f897b8acfa | 26 | case 2: // bus off, no control |
wataaki | 0:62f897b8acfa | 27 | case 3: // bus off, has control |
wataaki | 0:62f897b8acfa | 28 | case 6: // bus on, no control |
wataaki | 0:62f897b8acfa | 29 | cmd[0] = 1; // PCA9541 コマンドコード Cont Reg |
wataaki | 0:62f897b8acfa | 30 | cmd[1] = 5; // bus on, has control |
wataaki | 0:62f897b8acfa | 31 | i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み |
wataaki | 0:62f897b8acfa | 32 | i2c.read( 0xe2, cmd, 1); // Cont Regを読込み |
wataaki | 0:62f897b8acfa | 33 | break; |
wataaki | 0:62f897b8acfa | 34 | case 9: // bus on, no control |
wataaki | 0:62f897b8acfa | 35 | case 0xc: // bus on, no control |
wataaki | 0:62f897b8acfa | 36 | case 0xd: // bus off, no control |
wataaki | 0:62f897b8acfa | 37 | cmd[0] = 1; // PCA9541 コマンドコード Cont Reg |
wataaki | 0:62f897b8acfa | 38 | cmd[1] = 0; // bus on, has control |
wataaki | 0:62f897b8acfa | 39 | i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み |
wataaki | 0:62f897b8acfa | 40 | i2c.read( 0xe2, cmd, 1); // Cont Regを読込み |
wataaki | 0:62f897b8acfa | 41 | break; |
wataaki | 0:62f897b8acfa | 42 | case 0xa: // bus on, no control |
wataaki | 0:62f897b8acfa | 43 | case 0xe: // bus off, no control |
wataaki | 0:62f897b8acfa | 44 | case 0xf: // bus on, has control |
wataaki | 0:62f897b8acfa | 45 | cmd[0] = 1; // PCA9541 コマンドコード Cont Reg |
wataaki | 0:62f897b8acfa | 46 | cmd[1] = 1; // bus on, has control |
wataaki | 0:62f897b8acfa | 47 | i2c.write( 0xe2, cmd, 2); // Cont Regにcmd[1]を書込み |
wataaki | 0:62f897b8acfa | 48 | i2c.read( 0xe2, cmd, 1); // Cont Regを読込み |
wataaki | 0:62f897b8acfa | 49 | break; |
wataaki | 0:62f897b8acfa | 50 | default: |
wataaki | 0:62f897b8acfa | 51 | break; |
wataaki | 0:62f897b8acfa | 52 | } |
wataaki | 0:62f897b8acfa | 53 | |
wataaki | 0:62f897b8acfa | 54 | cmd[0] = sel; // PCA9546 Cont Reg sel channel enabled |
wataaki | 0:62f897b8acfa | 55 | i2c.write( 0xe8, cmd, 1); // Send command string |
wataaki | 0:62f897b8acfa | 56 | } |
wataaki | 0:62f897b8acfa | 57 | |
wataaki | 0:62f897b8acfa | 58 | int main () |
wataaki | 0:62f897b8acfa | 59 | { |
wataaki | 0:62f897b8acfa | 60 | i2c.frequency(100000); |
wataaki | 0:62f897b8acfa | 61 | pc.printf("PCA9541A Sample Program\r\n"); |
wataaki | 0:62f897b8acfa | 62 | |
wataaki | 0:62f897b8acfa | 63 | set_ch(1); // PCA9541Aによりマスターを選択後 |
wataaki | 0:62f897b8acfa | 64 | // PCA9546によりchnに接続 |
wataaki | 0:62f897b8acfa | 65 | |
wataaki | 0:62f897b8acfa | 66 | // PCA9541A |
wataaki | 0:62f897b8acfa | 67 | while(1); |
wataaki | 0:62f897b8acfa | 68 | } |