noop din
/
ADCandticker_sample
the code for Lab3
Fork of ADCandticker_sample by
main.cpp
- Committer:
- toh2018
- Date:
- 2018-02-09
- Revision:
- 4:8edcd6d3c39f
- Parent:
- 3:2db0cd79282b
- Child:
- 5:3bd67c8bb0ee
File content as of revision 4:8edcd6d3c39f:
// LAB 3 SAMPLE PROGRAM 1 // Revised for mbed 5 #include "mbed.h" Ticker tick; // Ticker for reading analog AnalogIn ain(A0) ; // Analog input DigitalOut led1(D8); // Red LED DigitalOut led2(D9); DigitalOut led3(D10); DigitalOut led4(D11); DigitalOut led5(D12); Serial pc(USBTX, USBRX); // tx, rx, for debugging DigitalIn b1(PTE1,PullUp); Thread pollT ; // thread to poll volatile int pressEvent = 0 ; // Variabe set by the polling thread volatile int maxvolt = 330; /// implement the botton here ///////////////////////////////////// enum buttonPos { up, down, bounce }; // Button positions void polling() { buttonPos pos = up ; int bcounter = 0 ; while (true) { 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 ; } Thread::wait(30); } } // end the button ////////////////////////////////////////////////// // Message type typedef struct { 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 // 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) ; samples++ ; if (samples == 10) { // send to thread message_t *mess = mailbox.alloc() ; // may fail but does not block if (mess) { mess->analog = smoothed ; 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) { s[3] = '0' + (v % 10) ; v = v / 10 ; s[2] = '0' + (v % 10) ; v = v / 10 ; s[0] = '0' + (v % 10) ; } // Main program // Initialise variables // Attach ISR for ticker // Procss messages from mailbox int main() { led1 = 1 ; // turn off led2 = 1; led3 = 1; led4 = 1; led5 = 1; int volts = 0 ; //const int threshold = 100 ; const int threshold1 = 55 ; const int threshold2 = 110 ; const int threshold3 = 165 ; const int threshold4 = 220 ; const int threshold5 = 275 ; int counter = 0 ; char vstring[] = "X.XX\r\n" ; tick.attach_us(callback(&readA0), 10000); // ticks every 10ms while (true) { osEvent evt = mailbox.get(); // wait for mail if (evt.status == osEventMail) { message_t* mess = (message_t*)evt.value.p ; volts = (mess->analog * 330) / 0xffff ; mailbox.free(mess) ; // free the message space ////press event //////////////////////////////////// if(pressEvent) { pressEvent =0; maxvolt = volts; /// update the threshold here } // End of the pressEvent //////////////////////////// if (volts > threshold1) led1 = 1 ; else led1 = 0 ; if (volts > threshold2) led2 = 1 ; else led2 = 0 ; if (volts > threshold3) led3 = 1 ; else led3 = 0 ; if (volts > threshold4) led4 = 1 ; else led4 = 0 ; if (volts > threshold5) led5 = 1 ; else led5 = 0 ; vToString(volts, vstring) ; counter++ ; if (counter == 10) { // limit bandwidth of serial pc.printf(vstring) ; counter = 0 ; } } } }