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I2C_2 bus scanner for STM32L476RG.
main.cpp@6:02a058f2ec6f, 2016-03-21 (annotated)
- Committer:
- joeata2wh
- Date:
- Mon Mar 21 04:17:13 2016 +0000
- Revision:
- 6:02a058f2ec6f
- Parent:
- 5:a4fddd74263c
- Child:
- 7:5962e77516ac
updated comments
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
joeata2wh | 0:befb557584fb | 1 | /* Scan I2C bus on specified pins and prints out |
joeata2wh | 6:02a058f2ec6f | 2 | * the all address where an active device responds. |
joeata2wh | 0:befb557584fb | 3 | * |
joeata2wh | 0:befb557584fb | 4 | * By Joe Elsworth CTO of A2WH |
joeata2wh | 3:8def8fb70765 | 5 | * Free use for all but no warranty, no promises. |
joeata2wh | 6:02a058f2ec6f | 6 | * Don't forget 3K pull-up resistors on sda,scl |
joeata2wh | 2:e90c47d4f358 | 7 | * |
joeata2wh | 2:e90c47d4f358 | 8 | * I tested this by soldering in a I2C chip known to respond at |
joeata2wh | 2:e90c47d4f358 | 9 | * address dec=120 hex=70 and the utility got the ack as expected. |
joeata2wh | 2:e90c47d4f358 | 10 | * when the chip was de-soldered it was no longer detected. |
joeata2wh | 2:e90c47d4f358 | 11 | */ |
joeata2wh | 0:befb557584fb | 12 | |
joeata2wh | 0:befb557584fb | 13 | #include "mbed.h" |
joeata2wh | 0:befb557584fb | 14 | |
joeata2wh | 0:befb557584fb | 15 | Serial pc(USBTX, USBRX); |
joeata2wh | 0:befb557584fb | 16 | |
joeata2wh | 1:2363995f603f | 17 | #define D_SDA PB_7 |
joeata2wh | 0:befb557584fb | 18 | #define D_SCL PB_6 |
joeata2wh | 0:befb557584fb | 19 | // sda=PB7, scl=PB_6 Pins specific to Nucleo-F303K8 |
joeata2wh | 0:befb557584fb | 20 | // must change pins to match your board. |
joeata2wh | 0:befb557584fb | 21 | |
joeata2wh | 0:befb557584fb | 22 | I2C i2c(D_SDA, D_SCL); |
joeata2wh | 0:befb557584fb | 23 | |
joeata2wh | 0:befb557584fb | 24 | DigitalOut myled(LED1); |
joeata2wh | 0:befb557584fb | 25 | |
joeata2wh | 4:ad1195c10812 | 26 | int ack; |
joeata2wh | 6:02a058f2ec6f | 27 | int address; |
joeata2wh | 0:befb557584fb | 28 | void scanI2C() { |
joeata2wh | 0:befb557584fb | 29 | for(address=1;address<127;address++) { |
joeata2wh | 0:befb557584fb | 30 | ack = i2c.write(address, "11", 1); |
joeata2wh | 0:befb557584fb | 31 | if (ack == 0) { |
joeata2wh | 0:befb557584fb | 32 | pc.printf("\tFound at %3d -- %3x\r\n", address,address); |
joeata2wh | 0:befb557584fb | 33 | } |
joeata2wh | 0:befb557584fb | 34 | wait(0.05); |
joeata2wh | 0:befb557584fb | 35 | } |
joeata2wh | 0:befb557584fb | 36 | } |
joeata2wh | 0:befb557584fb | 37 | |
joeata2wh | 0:befb557584fb | 38 | int main() { |
joeata2wh | 0:befb557584fb | 39 | pc.baud(9600); |
joeata2wh | 0:befb557584fb | 40 | pc.printf("I2C scanner \r\n"); |
joeata2wh | 0:befb557584fb | 41 | scanI2C(); |
joeata2wh | 0:befb557584fb | 42 | pc.printf("Finished Scan\r\n"); |
joeata2wh | 5:a4fddd74263c | 43 | // just blink to let us know the CPU is alive |
joeata2wh | 0:befb557584fb | 44 | while(1) { |
joeata2wh | 0:befb557584fb | 45 | wait(5.0); |
joeata2wh | 0:befb557584fb | 46 | myled = !myled; |
joeata2wh | 0:befb557584fb | 47 | } |
joeata2wh | 0:befb557584fb | 48 | } |
joeata2wh | 0:befb557584fb | 49 |