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gestion encodeur 5048 par spi
Diff: as5048spi.cpp
- Revision:
- 0:5a1830df0b66
diff -r 000000000000 -r 5a1830df0b66 as5048spi.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/as5048spi.cpp Tue Oct 08 14:59:11 2019 +0000 @@ -0,0 +1,132 @@ +#include "as5048spi.h" + +As5048Spi::As5048Spi(PinName mosi, PinName miso, PinName sclk, PinName chipselect, int ndevices) : + _nDevices(ndevices), + _chipSelectN(chipselect), + _spi(mosi, miso, sclk) +{ + _chipSelectN.write(1); + // AS5048 needs 16-bits for is commands + // Mode = 1: + // clock polarity = 0 --> clock pulse is high + // clock phase = 1 --> sample on falling edge of clock pulse + _spi.format(16, 1); + + // Set clock frequency to 1 MHz (max is 10Mhz) + _spi.frequency(1000000); + + _readBuffer = new int[ndevices]; +} + +As5048Spi::~As5048Spi() +{ + delete [] _readBuffer; +} + +int As5048Spi::degrees(int sensor_result) +{ + return mask(sensor_result) * 36000 / 0x4000; +} + + +int As5048Spi::radian(int sensor_result) +{ + return mask(sensor_result) * 62832 / 0x4000; +} + +bool As5048Spi::error(int device) +{ + if( device == -1 ) { + for(int i = 0; i < _nDevices; ++i) { + if( _readBuffer[i] & 0x4000 ) { + return true; + } + } + } else if( device < _nDevices ) { + return (_readBuffer[device] & 0x4000) == 0x4000; + } + return false; +} + + +void As5048Spi::frequency(int hz) +{ + _spi.frequency(hz); +} + +int As5048Spi::mask(int sensor_result) +{ + return sensor_result & 0x3FFF; // return lowest 14-bits +} + + +void As5048Spi::mask(int* sensor_results, int n) +{ + for(int i = 0; i < n; ++i) { + sensor_results[i] &= 0x3FFF; + } +} + + +bool As5048Spi::parity_check(int sensor_result) +{ + // Use the LSb of result to keep track of parity (0 = even, 1 = odd) + int result = sensor_result; + + for(int i = 1; i <= 15; ++i) { + sensor_result >>= 1; + result ^= sensor_result; + } + // Parity should be even + return (result & 0x0001) == 0; +} + +const int* As5048Spi::read(As5048Command command) +{ + _read(command); // Send command to device(s) + return _read(AS_CMD_NOP); // Read-out device(s) +} + +const int* As5048Spi::read_sequential(As5048Command command) +{ + return _read(command); +} + +const int* As5048Spi::read_angle() +{ + _read(AS_CMD_ANGLE); // Send command to device(s) + return _read(AS_CMD_NOP); // Read-out device(s) +} + +const int* As5048Spi::read_angle_sequential() +{ + return _read(AS_CMD_ANGLE); +} + + +int* As5048Spi::_read(As5048Command command) +{ + if(_nDevices == 1) + { + // Give command to start reading the angle + _chipSelectN.write(0); + wait_us(1); // Wait at least 350ns after chip select + _readBuffer[0] = _spi.write(command); + _chipSelectN.write(1); + wait_us(1); // Wait at least 350ns after chip select + } else + { + // Enable the sensor on the chain + _chipSelectN.write(0); + wait_us(1); // Wait at least 350ns after chip select + for(int i = 0; i < _nDevices; ++i) + { + _readBuffer[i] = _spi.write(command); + } + _chipSelectN.write(1); + wait_us(1); // Wait at least 350ns after chip select + } + return _readBuffer; +} + +