Sebastian Barrera
/
Lab3_ADC
Proposed solution to lab 3
main.cpp@6:a5841dd9e3b2, 2020-02-27 (annotated)
- Committer:
- sebbarpar
- Date:
- Thu Feb 27 09:47:08 2020 +0000
- Revision:
- 6:a5841dd9e3b2
- Parent:
- 4:ebd00f94455a
Lab 3;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
WilliamMarshQMUL | 0:ad3cdc525b99 | 1 | |
sebbarpar | 6:a5841dd9e3b2 | 2 | // LAB 3 |
sebbarpar | 6:a5841dd9e3b2 | 3 | //After pressing the button, maximum voltage is set. |
sebbarpar | 6:a5841dd9e3b2 | 4 | //Divided by 5(5 LEDs) and each LED assigned a threshold. |
sebbarpar | 6:a5841dd9e3b2 | 5 | //LED is turned on when threshold is surpassed. |
WilliamMarshQMUL | 0:ad3cdc525b99 | 6 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 7 | #include "mbed.h" |
sebbarpar | 6:a5841dd9e3b2 | 8 | #include "sineTable.h" |
WilliamMarshQMUL | 1:126dd2f5fc2d | 9 | |
sebbarpar | 6:a5841dd9e3b2 | 10 | class AnalogOut_unsafe : public AnalogOut { |
sebbarpar | 6:a5841dd9e3b2 | 11 | public: |
sebbarpar | 6:a5841dd9e3b2 | 12 | AnalogOut_unsafe (PinName pin) : AnalogOut (pin) {} |
sebbarpar | 6:a5841dd9e3b2 | 13 | protected: |
sebbarpar | 6:a5841dd9e3b2 | 14 | virtual void lock() {} |
sebbarpar | 6:a5841dd9e3b2 | 15 | virtual void unlock() {} |
sebbarpar | 6:a5841dd9e3b2 | 16 | }; |
sebbarpar | 6:a5841dd9e3b2 | 17 | // -------------------------- |
sebbarpar | 6:a5841dd9e3b2 | 18 | |
sebbarpar | 6:a5841dd9e3b2 | 19 | Ticker tick ; // Creates periodic interrupt |
sebbarpar | 6:a5841dd9e3b2 | 20 | AnalogOut_unsafe ao(PTE30) ; // Analog output |
WilliamMarshQMUL | 0:ad3cdc525b99 | 21 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 22 | AnalogIn ain(A0) ; // Analog input |
sebbarpar | 6:a5841dd9e3b2 | 23 | //Connected LEDs |
sebbarpar | 6:a5841dd9e3b2 | 24 | DigitalOut led1(PTE1); |
sebbarpar | 6:a5841dd9e3b2 | 25 | DigitalOut led2(PTE0); |
sebbarpar | 6:a5841dd9e3b2 | 26 | DigitalOut led3(PTD7); |
sebbarpar | 6:a5841dd9e3b2 | 27 | DigitalOut led4(PTD6); |
sebbarpar | 6:a5841dd9e3b2 | 28 | DigitalOut led5(PTE31); |
sebbarpar | 6:a5841dd9e3b2 | 29 | //Button to set maximum voltage |
sebbarpar | 6:a5841dd9e3b2 | 30 | InterruptIn button(PTD5); //Button 1 |
sebbarpar | 6:a5841dd9e3b2 | 31 | |
WilliamMarshQMUL | 4:ebd00f94455a | 32 | EventQueue queue; // creates an event queue, to call read ADC |
WilliamMarshQMUL | 0:ad3cdc525b99 | 33 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 34 | Serial pc(USBTX, USBRX); // tx, rx, for debugging |
WilliamMarshQMUL | 0:ad3cdc525b99 | 35 | |
WilliamMarshQMUL | 4:ebd00f94455a | 36 | // This thread runs the event queue |
WilliamMarshQMUL | 4:ebd00f94455a | 37 | Thread eventThread ; |
WilliamMarshQMUL | 3:f5d7fddeef39 | 38 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 39 | // Message type |
WilliamMarshQMUL | 0:ad3cdc525b99 | 40 | typedef struct { |
WilliamMarshQMUL | 0:ad3cdc525b99 | 41 | uint16_t analog; /* Analog input value */ |
WilliamMarshQMUL | 0:ad3cdc525b99 | 42 | } message_t; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 43 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 44 | // Mail box |
WilliamMarshQMUL | 0:ad3cdc525b99 | 45 | Mail<message_t, 2> mailbox; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 46 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 47 | // Function called every 10ms to read ADC |
WilliamMarshQMUL | 4:ebd00f94455a | 48 | // Average using a low pass filter |
WilliamMarshQMUL | 0:ad3cdc525b99 | 49 | // Every 10th value is sent to mailbox |
WilliamMarshQMUL | 4:ebd00f94455a | 50 | volatile int samples = 0 ; |
WilliamMarshQMUL | 4:ebd00f94455a | 51 | volatile uint16_t smoothed = 0 ; |
sebbarpar | 6:a5841dd9e3b2 | 52 | volatile int buttonEvent=0; |
sebbarpar | 6:a5841dd9e3b2 | 53 | |
sebbarpar | 6:a5841dd9e3b2 | 54 | //Interrupt to detect button switch |
sebbarpar | 6:a5841dd9e3b2 | 55 | void buttonCallback(){ |
sebbarpar | 6:a5841dd9e3b2 | 56 | buttonEvent=1; |
sebbarpar | 6:a5841dd9e3b2 | 57 | } |
WilliamMarshQMUL | 4:ebd00f94455a | 58 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 59 | void readA0() { |
WilliamMarshQMUL | 4:ebd00f94455a | 60 | smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ; |
WilliamMarshQMUL | 4:ebd00f94455a | 61 | samples++ ; |
WilliamMarshQMUL | 4:ebd00f94455a | 62 | if (samples == 10) { |
WilliamMarshQMUL | 4:ebd00f94455a | 63 | // send to thread |
WilliamMarshQMUL | 4:ebd00f94455a | 64 | message_t *mess = mailbox.alloc() ; // may fail but does not block |
WilliamMarshQMUL | 4:ebd00f94455a | 65 | if (mess) { |
WilliamMarshQMUL | 4:ebd00f94455a | 66 | mess->analog = smoothed ; |
WilliamMarshQMUL | 4:ebd00f94455a | 67 | mailbox.put(mess); // fails but does not block if full |
WilliamMarshQMUL | 0:ad3cdc525b99 | 68 | } |
WilliamMarshQMUL | 4:ebd00f94455a | 69 | samples = 0; |
WilliamMarshQMUL | 4:ebd00f94455a | 70 | } |
WilliamMarshQMUL | 0:ad3cdc525b99 | 71 | } |
WilliamMarshQMUL | 0:ad3cdc525b99 | 72 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 73 | // Write voltage digits |
WilliamMarshQMUL | 0:ad3cdc525b99 | 74 | // v Voltage as scale int, e.g. 3.30 is 330 |
WilliamMarshQMUL | 0:ad3cdc525b99 | 75 | void vToString(int v, char* s) { |
WilliamMarshQMUL | 0:ad3cdc525b99 | 76 | s[3] = '0' + (v % 10) ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 77 | v = v / 10 ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 78 | s[2] = '0' + (v % 10) ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 79 | v = v / 10 ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 80 | s[0] = '0' + (v % 10) ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 81 | } |
WilliamMarshQMUL | 0:ad3cdc525b99 | 82 | |
sebbarpar | 6:a5841dd9e3b2 | 83 | |
sebbarpar | 6:a5841dd9e3b2 | 84 | |
sebbarpar | 6:a5841dd9e3b2 | 85 | |
sebbarpar | 6:a5841dd9e3b2 | 86 | // Function called periodically |
sebbarpar | 6:a5841dd9e3b2 | 87 | // Write new value to AnalogOut |
sebbarpar | 6:a5841dd9e3b2 | 88 | volatile int index = 0 ; // index into array of sin values |
sebbarpar | 6:a5841dd9e3b2 | 89 | void writeAout() { |
sebbarpar | 6:a5841dd9e3b2 | 90 | ao.write_u16(sine[index]) ; |
sebbarpar | 6:a5841dd9e3b2 | 91 | index = (index + 1) % 64 ; |
sebbarpar | 6:a5841dd9e3b2 | 92 | } |
sebbarpar | 6:a5841dd9e3b2 | 93 | |
sebbarpar | 6:a5841dd9e3b2 | 94 | volatile int t=312; |
sebbarpar | 6:a5841dd9e3b2 | 95 | volatile int freq=1; |
sebbarpar | 6:a5841dd9e3b2 | 96 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 97 | // Main program |
WilliamMarshQMUL | 0:ad3cdc525b99 | 98 | // Initialise variables |
WilliamMarshQMUL | 0:ad3cdc525b99 | 99 | // Attach ISR for ticker |
WilliamMarshQMUL | 0:ad3cdc525b99 | 100 | // Procss messages from mailbox |
WilliamMarshQMUL | 0:ad3cdc525b99 | 101 | int main() { |
sebbarpar | 6:a5841dd9e3b2 | 102 | led1=0 ; // turn off |
sebbarpar | 6:a5841dd9e3b2 | 103 | led2=0; |
sebbarpar | 6:a5841dd9e3b2 | 104 | led3=0; |
sebbarpar | 6:a5841dd9e3b2 | 105 | led4=0; |
sebbarpar | 6:a5841dd9e3b2 | 106 | led5=0; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 107 | int volts = 0 ; |
sebbarpar | 6:a5841dd9e3b2 | 108 | int i=0; |
sebbarpar | 6:a5841dd9e3b2 | 109 | int threshold[5]={400,400,400,400,400}; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 110 | int counter = 0 ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 111 | char vstring[] = "X.XX\r\n" ; |
sebbarpar | 6:a5841dd9e3b2 | 112 | char max[] = "X.XX\r\n" ;//For debugging |
sebbarpar | 6:a5841dd9e3b2 | 113 | int maxvalue=1; |
sebbarpar | 6:a5841dd9e3b2 | 114 | button.fall(&buttonCallback) ; |
WilliamMarshQMUL | 3:f5d7fddeef39 | 115 | |
WilliamMarshQMUL | 4:ebd00f94455a | 116 | // Start the event queue |
WilliamMarshQMUL | 4:ebd00f94455a | 117 | eventThread.start(callback(&queue, &EventQueue::dispatch_forever)); |
WilliamMarshQMUL | 4:ebd00f94455a | 118 | // call the readA0 function every 10ms |
WilliamMarshQMUL | 4:ebd00f94455a | 119 | queue.call_every(10, readA0) ; |
sebbarpar | 6:a5841dd9e3b2 | 120 | |
WilliamMarshQMUL | 0:ad3cdc525b99 | 121 | while (true) { |
WilliamMarshQMUL | 0:ad3cdc525b99 | 122 | osEvent evt = mailbox.get(); // wait for mail |
sebbarpar | 6:a5841dd9e3b2 | 123 | tick.attach_us(callback(&writeAout), t); // setup ticker to write to AnalogOut |
sebbarpar | 6:a5841dd9e3b2 | 124 | //pc.printf("%d",t); //For debugging |
WilliamMarshQMUL | 0:ad3cdc525b99 | 125 | if (evt.status == osEventMail) { |
WilliamMarshQMUL | 0:ad3cdc525b99 | 126 | message_t* mess = (message_t*)evt.value.p ; |
sebbarpar | 6:a5841dd9e3b2 | 127 | if (buttonEvent==1){//When button is pressed establish maximum value and thresholds |
sebbarpar | 6:a5841dd9e3b2 | 128 | buttonEvent=0; |
sebbarpar | 6:a5841dd9e3b2 | 129 | maxvalue=(mess->analog * 330) / 0xffff; |
sebbarpar | 6:a5841dd9e3b2 | 130 | for (i=1;i<=5;i++){ |
sebbarpar | 6:a5841dd9e3b2 | 131 | threshold[i-1]=maxvalue*i/5;//Set values for thresholds |
sebbarpar | 6:a5841dd9e3b2 | 132 | } |
sebbarpar | 6:a5841dd9e3b2 | 133 | } |
WilliamMarshQMUL | 0:ad3cdc525b99 | 134 | volts = (mess->analog * 330) / 0xffff ; |
sebbarpar | 6:a5841dd9e3b2 | 135 | //Calculate frequency to call the function to write the DAC |
sebbarpar | 6:a5841dd9e3b2 | 136 | freq=1+(49*volts/maxvalue); |
sebbarpar | 6:a5841dd9e3b2 | 137 | if (freq>50) freq=50; |
sebbarpar | 6:a5841dd9e3b2 | 138 | t=(1000000/(freq*64)); |
WilliamMarshQMUL | 0:ad3cdc525b99 | 139 | mailbox.free(mess) ; // free the message space |
sebbarpar | 6:a5841dd9e3b2 | 140 | //Turn on LEDs depending on the range of voltage |
sebbarpar | 6:a5841dd9e3b2 | 141 | if (volts < threshold[0]) led1 = 0 ; else led1 = 1 ; |
sebbarpar | 6:a5841dd9e3b2 | 142 | if (volts < threshold[1]) led2 = 0 ; else led2 = 1 ; |
sebbarpar | 6:a5841dd9e3b2 | 143 | if (volts < threshold[2]) led3 = 0 ; else led3 = 1 ; |
sebbarpar | 6:a5841dd9e3b2 | 144 | if (volts < threshold[3]) led4 = 0 ; else led4 = 1 ; |
sebbarpar | 6:a5841dd9e3b2 | 145 | if (volts < threshold[4]) led5 = 0 ; else led5 = 1 ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 146 | vToString(volts, vstring) ; |
sebbarpar | 6:a5841dd9e3b2 | 147 | vToString(maxvalue, max) ; |
WilliamMarshQMUL | 0:ad3cdc525b99 | 148 | counter++ ; |
sebbarpar | 6:a5841dd9e3b2 | 149 | /*if (counter == 10) { // limit bandwidth of serial |
sebbarpar | 6:a5841dd9e3b2 | 150 | //pc.printf(vstring) ; |
sebbarpar | 6:a5841dd9e3b2 | 151 | pc.printf("%d \n",freq); |
sebbarpar | 6:a5841dd9e3b2 | 152 | pc.printf("%d \n",t); |
WilliamMarshQMUL | 0:ad3cdc525b99 | 153 | counter = 0 ; |
sebbarpar | 6:a5841dd9e3b2 | 154 | }*/ //For debugging |
WilliamMarshQMUL | 0:ad3cdc525b99 | 155 | } |
WilliamMarshQMUL | 0:ad3cdc525b99 | 156 | } |
WilliamMarshQMUL | 0:ad3cdc525b99 | 157 | } |