49 lines
1.4 KiB
C++
49 lines
1.4 KiB
C++
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#include "usart.h"
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#include "print.h"
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#include "adcdma.h"
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#include "oneway.h"
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#include "fifo.h"
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////////////////////////////////////////////////////////
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/* Voltmetr měří na pinu PA2 napětí a vypisuje v mV.
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* Frekvence vzorkování je 1kHz, průměruje se to a
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* zobrazuje jednou za 120 ms (9600 Bd). */
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////////////////////////////////////////////////////////
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class Meassure : public OneWay {
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FIFO<unsigned, 8u> fifo;
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unsigned avg;
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public:
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explicit Meassure () noexcept : OneWay(), fifo(), avg(0u) {}
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unsigned int Send (uint16_t * const ptr, const unsigned int len) override;
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void out ();
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};
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////////////////////////////////////////////////////////
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static Usart serial (9600u);
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static Print cout (DEC);
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static AdcDma adc;
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static Meassure meas;
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////////////////////////////////////////////////////////
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int main () {
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cout += serial;
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adc.attach (meas);
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for (;;) {
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meas.out();
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}
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return 0;
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}
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////////////////////////////////////////////////////////
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static constexpr unsigned BK = 3316u << 4; // Mělo by to být přesně 3300.
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unsigned int Meassure::Send(uint16_t * const ptr, const unsigned int len) {
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for (unsigned n=0; n<len; n++) {
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const unsigned mv = (BK * ptr [n]) >> 16;
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avg = (avg * 15 + mv) >> 4; // klouzavý průměr s postupným zapomínáním
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}
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fifo.Write (avg);
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return 0;
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}
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void Meassure::out() {
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unsigned t;
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if (fifo.Read (t)) {
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cout << t << " mV\r\n";
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}
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}
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