Martin Smith
Interfacing the AS5045 using SPI
main.cpp@0:ce4a539ca1d4, 2010-10-22 (annotated)
- Committer:
- ms523
- Date:
- Fri Oct 22 17:36:47 2010 +0000
- Revision:
- 0:ce4a539ca1d4
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| ms523 | 0:ce4a539ca1d4 | 1 | /* This program is designed to interface with the AS5045 IC encoder |
| ms523 | 0:ce4a539ca1d4 | 2 | It calls a function to read the encoder value every second |
| ms523 | 0:ce4a539ca1d4 | 3 | The program then prints the vaule to a PC screen via hyperterminal*/ |
| ms523 | 0:ce4a539ca1d4 | 4 | |
| ms523 | 0:ce4a539ca1d4 | 5 | #include "mbed.h" |
| ms523 | 0:ce4a539ca1d4 | 6 | |
| ms523 | 0:ce4a539ca1d4 | 7 | Serial pc(USBTX, USBRX); |
| ms523 | 0:ce4a539ca1d4 | 8 | SPI spi(p5, p6, p7); // mosi, miso, sclk |
| ms523 | 0:ce4a539ca1d4 | 9 | DigitalOut cs(p25); |
| ms523 | 0:ce4a539ca1d4 | 10 | |
| ms523 | 0:ce4a539ca1d4 | 11 | long EncoderValue; |
| ms523 | 0:ce4a539ca1d4 | 12 | int Encoder; |
| ms523 | 0:ce4a539ca1d4 | 13 | |
| ms523 | 0:ce4a539ca1d4 | 14 | Ticker ReadEncoder; |
| ms523 | 0:ce4a539ca1d4 | 15 | |
| ms523 | 0:ce4a539ca1d4 | 16 | void Read(){ |
| ms523 | 0:ce4a539ca1d4 | 17 | |
| ms523 | 0:ce4a539ca1d4 | 18 | spi.format(9,2); // Setup the spi for 9 bit data, high steady state clock, |
| ms523 | 0:ce4a539ca1d4 | 19 | spi.frequency(500000); |
| ms523 | 0:ce4a539ca1d4 | 20 | cs = 0; // Select the device by seting chip select low |
| ms523 | 0:ce4a539ca1d4 | 21 | |
| ms523 | 0:ce4a539ca1d4 | 22 | // Send a dummy byte to receive the contents encoder |
| ms523 | 0:ce4a539ca1d4 | 23 | int upper = spi.write(0x00); |
| ms523 | 0:ce4a539ca1d4 | 24 | int lower = spi.write(0x00); |
| ms523 | 0:ce4a539ca1d4 | 25 | lower = lower >> 6; |
| ms523 | 0:ce4a539ca1d4 | 26 | upper = (upper << 6)+lower; |
| ms523 | 0:ce4a539ca1d4 | 27 | cs = 1; |
| ms523 | 0:ce4a539ca1d4 | 28 | |
| ms523 | 0:ce4a539ca1d4 | 29 | pc.printf("%d \r", upper); |
| ms523 | 0:ce4a539ca1d4 | 30 | } |
| ms523 | 0:ce4a539ca1d4 | 31 | |
| ms523 | 0:ce4a539ca1d4 | 32 | |
| ms523 | 0:ce4a539ca1d4 | 33 | int main() { |
| ms523 | 0:ce4a539ca1d4 | 34 | pc.printf("Hello World!\n"); |
| ms523 | 0:ce4a539ca1d4 | 35 | ReadEncoder.attach_us(&Read, 100000); // call flip every 100 milli-seconds |
| ms523 | 0:ce4a539ca1d4 | 36 | |
| ms523 | 0:ce4a539ca1d4 | 37 | while(1) { |
| ms523 | 0:ce4a539ca1d4 | 38 | } |
| ms523 | 0:ce4a539ca1d4 | 39 | } |
| ms523 | 0:ce4a539ca1d4 | 40 |