Oliver Broad / Mbed 2 deprecated MIC5821

Control of MIC5821 octal driver using a SPI port (port1) and I/O pin (p21)

Dependencies:   mbed

main.cpp@0:986765bd4f9e, 2012-07-08 (annotated)

Committer:
oliverb
Date:
Sun Jul 08 18:51:51 2012 +0000
Revision:
0:986765bd4f9e
Tested

Who changed what in which revision?

UserRevisionLine numberNew contents of line
oliverb 0:986765bd4f9e 1 #include "mbed.h"
oliverb 0:986765bd4f9e 2 // Use SPI port to write an 8 bit pattern to MIC5821 open collector driver device.
oliverb 0:986765bd4f9e 3 // MBED led1 lights if pattern read back from MIC5821 matches pattern written
oliverb 0:986765bd4f9e 4 // Ordinarily the device would be write-only but loopback may be usefull in testing.
oliverb 0:986765bd4f9e 5 // Cascade output is NOT tristate. Strobe is NOT a CS/SS signal, needs a pulse.
oliverb 0:986765bd4f9e 6 //
oliverb 0:986765bd4f9e 7 // Note that the MIC has a speed limit, 3.3MHz at 5v, mine works OK at 1MHz at 3.3v
oliverb 0:986765bd4f9e 8 // Also input has CMOS thresholds so it may not recognise MBED logic HI when powered
oliverb 0:986765bd4f9e 9 // from 5v so power it from Vout.
oliverb 0:986765bd4f9e 10 //
oliverb 0:986765bd4f9e 11 // Data is clocked in on rising edges so SPI 0,0 or SPI 1,1.
oliverb 0:986765bd4f9e 12
oliverb 0:986765bd4f9e 13 SPI spi(p5, p6, p7); // mosi, miso, sclk
oliverb 0:986765bd4f9e 14
oliverb 0:986765bd4f9e 15 DigitalOut strobe(p21);
oliverb 0:986765bd4f9e 16 DigitalOut led(LED1);
oliverb 0:986765bd4f9e 17
oliverb 0:986765bd4f9e 18 int main() {
oliverb 0:986765bd4f9e 19 spi.format(8,0);
oliverb 0:986765bd4f9e 20 spi.frequency(1000000);
oliverb 0:986765bd4f9e 21 char leds,prev;
oliverb 0:986765bd4f9e 22 leds=0;
oliverb 0:986765bd4f9e 23 while(1) {
oliverb 0:986765bd4f9e 24 prev=spi.write(leds)+1;
oliverb 0:986765bd4f9e 25 led=(prev == leds);
oliverb 0:986765bd4f9e 26 leds++;
oliverb 0:986765bd4f9e 27 strobe=1;
oliverb 0:986765bd4f9e 28 wait_us(1);
oliverb 0:986765bd4f9e 29 strobe=0;
oliverb 0:986765bd4f9e 30 wait(0.5);
oliverb 0:986765bd4f9e 31 }
oliverb 0:986765bd4f9e 32 }