Soheil Novinfard
/
DACandticker_modified_2
Digital To Analogue Converter
Fork of ADCandticker_sample by
Diff: main.cpp
- Revision:
- 2:9e3a110b66ee
- Parent:
- 1:126dd2f5fc2d
diff -r 126dd2f5fc2d -r 9e3a110b66ee main.cpp --- a/main.cpp Wed Jan 24 21:55:43 2018 +0000 +++ b/main.cpp Fri Feb 09 15:57:42 2018 +0000 @@ -3,29 +3,82 @@ // Revised for mbed 5 #include "mbed.h" +#include "sineTable.h" + Ticker tick; // Ticker for reading analog AnalogIn ain(A0) ; // Analog input -DigitalOut led1(LED_RED); // Red LED +DigitalOut led1(PTA12); +DigitalOut led2(PTA4); +DigitalOut led3(PTA5); +DigitalOut led4(PTC8); +DigitalOut led5(PTC9); +Serial pc(USBTX, USBRX); // tx, rx, for debugging + +DigitalIn b1(PTD0, PullUp); + +volatile int pressEvent = 0 ; // Variabe set by the polling thread + +AnalogOut ao(PTE30) ; // Analog output + +// Function called periodically +// Write new value to AnalogOut +volatile int index = 0 ; // index into array of sin values +void writeAout() { + ao.write_u16(sine[index]) ; + index = (index + 1) % 64 ; +} -Serial pc(USBTX, USBRX); // tx, rx, for debugging +enum buttonPos { up, down, bounce }; // Button positions +void polling() +{ + buttonPos pos = up ; + int bcounter = 0 ; + + switch (pos) { + case up : + if (!b1.read()) { // now down + pressEvent = 1 ; // transition occurred + pos = down ; + } + break ; + case down : + if (b1 == 1) { // no longer down + bcounter = 3 ; // wait four cycles + pos = bounce ; + } + break ; + case bounce : + if (b1 == 0) { // down again - button has bounced + pos = down ; // no event + } else if (bcounter == 0) { + pos = up ; // delay passed - reset to up + } else { + bcounter-- ; // continue waiting + } + break ; + + } +} // Message type typedef struct { - uint16_t analog; /* Analog input value */ + uint16_t analog; /* Analog input value */ } message_t; // Mail box Mail<message_t, 2> mailbox; // Function called every 10ms to read ADC -// Low pass filter +// Low pass filter // Every 10th value is sent to mailbox volatile int samples = 0 ; -volatile uint16_t smoothed = 0 ; -void readA0() { - smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ; +volatile uint16_t smoothed = 0 ; +void readA0() +{ + polling(); + smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ; // divided by 2 - reduce the signal noise samples++ ; if (samples == 10) { // send to thread @@ -35,12 +88,13 @@ mailbox.put(mess); // fails but does not block if full } samples = 0; - } + } } // Write voltage digits // v Voltage as scale int, e.g. 3.30 is 330 -void vToString(int v, char* s) { +void vToString(int v, char* s) +{ s[3] = '0' + (v % 10) ; v = v / 10 ; s[2] = '0' + (v % 10) ; @@ -51,24 +105,94 @@ // Main program // Initialise variables // Attach ISR for ticker -// Procss messages from mailbox -int main() { - led1 = 1 ; // turn off +// Procss messages from mailbox +int main() +{ + led1 = 1 ; // turn off int volts = 0 ; - const int threshold = 100 ; + int threshold = 100 ; // 1 vol int counter = 0 ; char vstring[] = "X.XX\r\n" ; + + int update_us = 1000 ; // 1ms - tick.attach_us(callback(&readA0), 10000); // ticks every 10ms + tick.attach_us(callback(&readA0), 10000); // ticks every 10ms -> 10000 micro second + + while (true) { - osEvent evt = mailbox.get(); // wait for mail + + + + osEvent evt = mailbox.get(); // wait for mail + + if (pressEvent) { + pressEvent = 0 ; // clear the event variable + threshold = volts; + + } + + // every 100 ms this loop operates if (evt.status == osEventMail) { message_t* mess = (message_t*)evt.value.p ; - volts = (mess->analog * 330) / 0xffff ; + volts = (mess->analog * 330) / 0xffff ; // 2 ^ 16 mailbox.free(mess) ; // free the message space - if (volts > threshold) led1 = 0 ; else led1 = 1 ; + + int f = (1+49*volts/threshold); + if(f<1) + f =1; + else if(f>50) + f=50; + + update_us = 1/(64*f); + tick.attach_us(callback(&writeAout), update_us); // setup ticker to write to AnalogOut + + + if(volts < (threshold / 6)) { + led1 = 1; + led2 = 1; + led3 = 1; + led4 = 1; + led5 = 1; + } + if((volts > (threshold * 1/ 6))&&(volts < (threshold * 2/ 6))) { + led1 = 0; + led2 = 1; + led3 = 1; + led4 = 1; + led5 = 1; + } + if((volts > (threshold * 2/ 6))&&(volts < (threshold * 3/ 6))) { + led1 = 0; + led2 = 0; + led3 = 1; + led4 = 1; + led5 = 1; + } + if((volts > (threshold * 3/ 6))&&(volts < (threshold * 4/ 6))) { + led1 = 0; + led2 = 0; + led3 = 0; + led4 = 1; + led5 = 1; + } + if((volts > (threshold * 4/ 6))&&(volts < (threshold * 5/ 6))) { + led1 = 0; + led2 = 0; + led3 = 0; + led4 = 0; + led5 = 1; + } + if(volts > (threshold * 5/ 6)) { + led1 = 0; + led2 = 0; + led3 = 0; + led4 = 0; + led5 = 0; + } vToString(volts, vstring) ; counter++ ; + + // every 1 s this loop will operate if (counter == 10) { // limit bandwidth of serial pc.printf(vstring) ; counter = 0 ;