Jeroen Lodder
/
max11626_example
Simple test code with an max11626eee
main.cpp
- Committer:
- jeroen3
- Date:
- 2016-07-27
- Revision:
- 0:afa6a5e2d11a
File content as of revision 0:afa6a5e2d11a:
#include "mbed.h" DigitalOut myled(LED1); DigitalOut convst(p18); // Conversion Start (active low) DigitalOut cs(p16); // Chip Select (active low) DigitalIn eoc(p20); // End of Conversion (active low) SPI spi(p11, p12, p13); // mosi, miso, sclk Serial pc(USBTX, USBRX); // tx, rx #define AIN0 0u #define AIN1 1u #define AIN2 2u #define AIN3 3u #define AIN4 4u #define AIN5 5u #define AIN6 6u #define AIN7 7u #define AIN8 8u #define AIN9 9u #define AIN10 10u #define AIN11 11u #define AIN12 12u #define AIN13 13u #define AIN14 14u #define AIN15 15u #define SCAN_TO_N 0u // Scans channels 0 through N. #define SCAN_N_TO 1u // Scans channels N through the highest numbered channel. #define SCAN_N_AVG 2u // Scans channel N repeatedly. The averaging register sets the number of results. #define SCAN_OFF 3u // No scan. Converts channel N once only #define CLKSEL_INT_INT_CNVST 0u // Internal clock, internal aqcuisition, convst #define CLKSEL_INT_EXT_CNVST 1u // Internal clock, external aqcuisition convst, convst #define CLKSEL_INT_INT_ADC 2u // Internal clock, internal aqcuisition, extra channel #define CLKSEL_EXT_EXT_ADC 3u // External clock, external aqcuisition sclk, extra channel #define REFSEL_INT_SLEEP 0u // Reference off after scan; need wake-up delay #define REFSEL_EXT 1u // Reference off; no wake-up delay. #define REFSEL_INT_NOSLEEP 2u // Reference always on; no wake-up delay. #define REFSEL_RESERVED 3u // Reserved. Do not use. #define NAVG_4 0u // Performs four conversions and returns the average for each requested result. #define NAVG_8 1u // Performs eight conversions and returns the average for each requested result. #define NAVG_16 2u // Performs 16 conversions and returns the average for each requested result. #define NAVG_32 3u // Performs 32 conversions and returns the average for each requested result. #define NSCAN_4 0u // Scans channel N and returns four results. #define NSCAN_8 1u // Scans channel N and returns eight results. #define NSCAN_12 2u // Scans channel N and returns 12 results. #define NSCAN_16 3u // Scans channel N and returns 16 results. uint8_t compile_reset(bool fifo_only){ if(fifo_only) return 0x18; else return 0x10; } uint8_t compile_conversion(uint8_t ch, uint8_t scan){ return 0x80 | ((ch&0xF)<<3)|((scan&0x3)<<1); } uint8_t compile_setup(uint8_t clk, uint8_t ref){ return 0x40 | ((clk&0x3)<<4)|((ref&0x3)<<2); } uint8_t compile_avg(bool avgon, uint8_t navg, uint8_t nscan){ uint8_t y = 0x20; if(avgon) y |= 0x10; y |= ((navg&0x3)<<2)|(nscan&0x3); return y; } int main() { int data[4]; convst = 1; cs = 1; // The max11626 uses normal 8 bit spi for the registers. // However, >8 bit reads can be used to read the data (mosi would be 0 during read). spi.format(8,3); spi.frequency(10000); // MAX11626 addressing. // Addressing is performed by the leading zeros. // - no leading zero (0x80) would be the conversion register. // - one leading zeros (0x40) would be the setup register. // - two leading zeros (0x20) would be the averaging register. // - 3 leading zeros (0x10) would be the reset register. // Transfers are MSB first. // Reading data is always safe when you set MOSI to 0. // Let the scope settle after reset wait(1); while(1) { // Write reset full. cs = 0; spi.write(compile_reset(0)); cs = 1; wait_us(100); // Write conversion cs = 0; spi.write(compile_conversion(AIN3, SCAN_TO_N)); cs = 1; wait_us(100); convst = 0; wait_us(100); convst = 1; wait_us(100); cs = 0; // Read 4 for(int i=0; i<4; i++){ data[i] = 0; data[i] = spi.write(0); data[i] <<= 8; data[i] |= spi.write(0); } cs = 1; pc.printf("%05d, %05d, %05d, %05d\n",data[0],data[1],data[2],data[3]); wait(0.2); myled = !myled; } }