jim hamblen
I2C debug program for use with RealTerm. Sends I2C commands to P9 and P10. Run program on mbed. Start RealTerm, select the mbed virtual com port under the port tab, then open RealTerm's I2C command tab. Reset mbed. See http://mbed.org/users/4180_1/notebook/i2c-debug-for-realterm/ for instructions
main.cpp@0:0c54b73b002c, 2011-03-08 (annotated)
- Committer:
- 4180_1
- Date:
- Tue Mar 08 03:16:34 2011 +0000
- Revision:
- 0:0c54b73b002c
- Child:
- 1:be1498ba7fb4
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| 4180_1 | 0:0c54b73b002c | 1 | #include "mbed.h" |
| 4180_1 | 0:0c54b73b002c | 2 | |
| 4180_1 | 0:0c54b73b002c | 3 | // The program sends and receives I2C commands using RealTerm's I2C tab feature |
| 4180_1 | 0:0c54b73b002c | 4 | // Run Realterm on PC and this program on mbed |
| 4180_1 | 0:0c54b73b002c | 5 | // In RealTerm connect to the mbed's USB virtual COM port |
| 4180_1 | 0:0c54b73b002c | 6 | // Switch to I2C tab |
| 4180_1 | 0:0c54b73b002c | 7 | // Type in I2C address & data to read and write and see the response |
| 4180_1 | 0:0c54b73b002c | 8 | // It is handy to debug complex I2C hardware setups |
| 4180_1 | 0:0c54b73b002c | 9 | // Prints "noack!" when no I2C device responds |
| 4180_1 | 0:0c54b73b002c | 10 | DigitalOut myled(LED1); |
| 4180_1 | 0:0c54b73b002c | 11 | Serial pc(USBTX, USBRX); |
| 4180_1 | 0:0c54b73b002c | 12 | I2C i2c(p9,p10); |
| 4180_1 | 0:0c54b73b002c | 13 | |
| 4180_1 | 0:0c54b73b002c | 14 | char data_length=0; |
| 4180_1 | 0:0c54b73b002c | 15 | int read=0; |
| 4180_1 | 0:0c54b73b002c | 16 | int write=0; |
| 4180_1 | 0:0c54b73b002c | 17 | |
| 4180_1 | 0:0c54b73b002c | 18 | //ugly code structure - should start over and fix this later |
| 4180_1 | 0:0c54b73b002c | 19 | //now that I understand syntax for command strings a bit more - but it works |
| 4180_1 | 0:0c54b73b002c | 20 | // Read in two ASCII characters and convert to a byte |
| 4180_1 | 0:0c54b73b002c | 21 | // ...unless a command character is found |
| 4180_1 | 0:0c54b73b002c | 22 | int getbyte(char *data) { |
| 4180_1 | 0:0c54b73b002c | 23 | char charin=0; |
| 4180_1 | 0:0c54b73b002c | 24 | charin = pc.getc(); |
| 4180_1 | 0:0c54b73b002c | 25 | if (charin == 'R') { |
| 4180_1 | 0:0c54b73b002c | 26 | read=1; |
| 4180_1 | 0:0c54b73b002c | 27 | if (getbyte(&data_length)==0) pc.printf("error"); |
| 4180_1 | 0:0c54b73b002c | 28 | return 2; |
| 4180_1 | 0:0c54b73b002c | 29 | } |
| 4180_1 | 0:0c54b73b002c | 30 | if (charin == 'P') return 3; |
| 4180_1 | 0:0c54b73b002c | 31 | if (charin > 'F') return 0; |
| 4180_1 | 0:0c54b73b002c | 32 | if (charin <='9') charin = charin - '0'; |
| 4180_1 | 0:0c54b73b002c | 33 | else charin = charin +10 - 'A'; |
| 4180_1 | 0:0c54b73b002c | 34 | *data = charin << 4; |
| 4180_1 | 0:0c54b73b002c | 35 | charin = pc.getc(); |
| 4180_1 | 0:0c54b73b002c | 36 | if (charin > 'F') return 0; |
| 4180_1 | 0:0c54b73b002c | 37 | if (charin <='9') charin = charin - '0'; |
| 4180_1 | 0:0c54b73b002c | 38 | else charin = charin +10 - 'A'; |
| 4180_1 | 0:0c54b73b002c | 39 | *data = *data | charin; |
| 4180_1 | 0:0c54b73b002c | 40 | return 1; |
| 4180_1 | 0:0c54b73b002c | 41 | } |
| 4180_1 | 0:0c54b73b002c | 42 | int main() { |
| 4180_1 | 0:0c54b73b002c | 43 | |
| 4180_1 | 0:0c54b73b002c | 44 | char command=0; |
| 4180_1 | 0:0c54b73b002c | 45 | char address=0x40; |
| 4180_1 | 0:0c54b73b002c | 46 | char data[255]; |
| 4180_1 | 0:0c54b73b002c | 47 | char cmd[255]; |
| 4180_1 | 0:0c54b73b002c | 48 | int cmd_count=0; |
| 4180_1 | 0:0c54b73b002c | 49 | int more_cmd = 0; |
| 4180_1 | 0:0c54b73b002c | 50 | int i=0; |
| 4180_1 | 0:0c54b73b002c | 51 | myled=1; |
| 4180_1 | 0:0c54b73b002c | 52 | data[0]=0; |
| 4180_1 | 0:0c54b73b002c | 53 | data[1]=0; |
| 4180_1 | 0:0c54b73b002c | 54 | i2c.frequency(75000); |
| 4180_1 | 0:0c54b73b002c | 55 | i2c.start(); |
| 4180_1 | 0:0c54b73b002c | 56 | i2c.start(); |
| 4180_1 | 0:0c54b73b002c | 57 | pc.printf("\fmbed I2C ready\n\r"); |
| 4180_1 | 0:0c54b73b002c | 58 | // loop forever waiting for PC serial commands |
| 4180_1 | 0:0c54b73b002c | 59 | while (1) { |
| 4180_1 | 0:0c54b73b002c | 60 | command = pc.getc(); |
| 4180_1 | 0:0c54b73b002c | 61 | switch (command) { |
| 4180_1 | 0:0c54b73b002c | 62 | case 'S': |
| 4180_1 | 0:0c54b73b002c | 63 | //Start - automatic start sent on read or write |
| 4180_1 | 0:0c54b73b002c | 64 | data_length=0; |
| 4180_1 | 0:0c54b73b002c | 65 | cmd_count=0; |
| 4180_1 | 0:0c54b73b002c | 66 | read=0; |
| 4180_1 | 0:0c54b73b002c | 67 | write=0; |
| 4180_1 | 0:0c54b73b002c | 68 | // in case of multiple starts |
| 4180_1 | 0:0c54b73b002c | 69 | while (getbyte(&address)==0) {i2c.start();}; |
| 4180_1 | 0:0c54b73b002c | 70 | pc.printf(" - I2C address=%2.2X ", address); |
| 4180_1 | 0:0c54b73b002c | 71 | //odd address means a read, otherwise a write |
| 4180_1 | 0:0c54b73b002c | 72 | if ((address & 0x01) == 1) read=1; |
| 4180_1 | 0:0c54b73b002c | 73 | else write=1; |
| 4180_1 | 0:0c54b73b002c | 74 | if (read ==1) { |
| 4180_1 | 0:0c54b73b002c | 75 | //read number of bytes to read |
| 4180_1 | 0:0c54b73b002c | 76 | if (getbyte(&data_length)==0) break; |
| 4180_1 | 0:0c54b73b002c | 77 | } |
| 4180_1 | 0:0c54b73b002c | 78 | if (write==1) { |
| 4180_1 | 0:0c54b73b002c | 79 | more_cmd =1; |
| 4180_1 | 0:0c54b73b002c | 80 | while (more_cmd==1) { |
| 4180_1 | 0:0c54b73b002c | 81 | if (getbyte(&cmd[cmd_count])>=2) { |
| 4180_1 | 0:0c54b73b002c | 82 | pc.printf(" write "); |
| 4180_1 | 0:0c54b73b002c | 83 | // write I2C command(s) |
| 4180_1 | 0:0c54b73b002c | 84 | if (i2c.write(address, cmd, cmd_count)!=0) pc.printf(" noack! "); |
| 4180_1 | 0:0c54b73b002c | 85 | for (i=0; i<cmd_count; i++) |
| 4180_1 | 0:0c54b73b002c | 86 | pc.printf(" command=%2.2X ", cmd[i]); |
| 4180_1 | 0:0c54b73b002c | 87 | cmd_count=0; |
| 4180_1 | 0:0c54b73b002c | 88 | more_cmd=0; |
| 4180_1 | 0:0c54b73b002c | 89 | write = 0; |
| 4180_1 | 0:0c54b73b002c | 90 | } else cmd_count++; |
| 4180_1 | 0:0c54b73b002c | 91 | } |
| 4180_1 | 0:0c54b73b002c | 92 | if (read==0) pc.printf("\n\r");; |
| 4180_1 | 0:0c54b73b002c | 93 | } |
| 4180_1 | 0:0c54b73b002c | 94 | break; |
| 4180_1 | 0:0c54b73b002c | 95 | case 'P': |
| 4180_1 | 0:0c54b73b002c | 96 | //Stop |
| 4180_1 | 0:0c54b73b002c | 97 | if (read == 1) { |
| 4180_1 | 0:0c54b73b002c | 98 | pc.printf(" read "); |
| 4180_1 | 0:0c54b73b002c | 99 | // read I2C data |
| 4180_1 | 0:0c54b73b002c | 100 | if (i2c.read(address, data, data_length)!=0) pc.printf(" noack! "); |
| 4180_1 | 0:0c54b73b002c | 101 | read = 0; |
| 4180_1 | 0:0c54b73b002c | 102 | write = 0; |
| 4180_1 | 0:0c54b73b002c | 103 | // send I2C data back to PC serial port |
| 4180_1 | 0:0c54b73b002c | 104 | for (i=0; i<data_length; i++) |
| 4180_1 | 0:0c54b73b002c | 105 | pc.printf(" data=%2.2X ",data[i]); |
| 4180_1 | 0:0c54b73b002c | 106 | } |
| 4180_1 | 0:0c54b73b002c | 107 | pc.printf("\n\r"); |
| 4180_1 | 0:0c54b73b002c | 108 | data_length=0; |
| 4180_1 | 0:0c54b73b002c | 109 | cmd_count=0; |
| 4180_1 | 0:0c54b73b002c | 110 | i2c.stop(); |
| 4180_1 | 0:0c54b73b002c | 111 | break; |
| 4180_1 | 0:0c54b73b002c | 112 | case 'R': |
| 4180_1 | 0:0c54b73b002c | 113 | //automatic read after write - read number of bytes to read |
| 4180_1 | 0:0c54b73b002c | 114 | if (getbyte(&data_length)==0) break; |
| 4180_1 | 0:0c54b73b002c | 115 | break; |
| 4180_1 | 0:0c54b73b002c | 116 | case '?': |
| 4180_1 | 0:0c54b73b002c | 117 | //Status |
| 4180_1 | 0:0c54b73b002c | 118 | pc.printf(" mbed ready \n\r"); |
| 4180_1 | 0:0c54b73b002c | 119 | break; |
| 4180_1 | 0:0c54b73b002c | 120 | default: |
| 4180_1 | 0:0c54b73b002c | 121 | |
| 4180_1 | 0:0c54b73b002c | 122 | myled = 0; |
| 4180_1 | 0:0c54b73b002c | 123 | break; |
| 4180_1 | 0:0c54b73b002c | 124 | } |
| 4180_1 | 0:0c54b73b002c | 125 | |
| 4180_1 | 0:0c54b73b002c | 126 | |
| 4180_1 | 0:0c54b73b002c | 127 | } |
| 4180_1 | 0:0c54b73b002c | 128 | } |