mirror of
https://github.com/JeffersGlass/DDS_VFO.git
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114 lines
4.9 KiB
Plaintext
114 lines
4.9 KiB
Plaintext
/* Encoder Library - SpeedTest - for measuring maximum Encoder speed
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* http://www.pjrc.com/teensy/td_libs_Encoder.html
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*
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* This example code is in the public domain.
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*/
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// This SpeedTest example provides a simple way to verify how much
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// CPU time Encoder is consuming. Connect a DC voltmeter to the
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// output pin and measure the voltage while the encoder is stopped
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// or running at a very slow speed. Even though the pin is rapidly
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// pulsing, a DC voltmeter will show the average voltage. Due to
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// software timing, it will read a number much less than a steady
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// logic high, but this number will give you a baseline reading
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// for output with minimal interrupt overhead. Then increase the
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// encoder speed. The voltage will decrease as the processor spends
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// more time in Encoder's interrupt routines counting the pulses
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// and less time pulsing the output pin. When the voltage is
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// close to zero and will not decrease any farther, you have reached
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// the absolute speed limit. Or, if using a mechanical system where
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// you reach a speed limit imposed by your motors or other hardware,
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// the amount this voltage has decreased, compared to the baseline,
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// should give you a good approximation of the portion of available
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// CPU time Encoder is consuming at your maximum speed.
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// Encoder requires low latency interrupt response. Available CPU
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// time does NOT necessarily prove or guarantee correct performance.
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// If another library, like NewSoftSerial, is disabling interrupts
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// for lengthy periods of time, Encoder can be prevented from
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// properly counting the intput signals while interrupt are disabled.
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// This optional setting causes Encoder to use more optimized code,
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// but the downside is a conflict if any other part of your sketch
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// or any other library you're using requires attachInterrupt().
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// It must be defined before Encoder.h is included.
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//#define ENCODER_OPTIMIZE_INTERRUPTS
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#include <Encoder.h>
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#include "pins_arduino.h"
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// Change these two numbers to the pins connected to your encoder
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// or shift register circuit which emulates a quadrature encoder
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// case 1: both pins are interrupts
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// case 2: only first pin used as interrupt
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Encoder myEnc(5, 6);
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// Connect a DC voltmeter to this pin.
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const int outputPin = 12;
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/* This simple circuit, using a Dual Flip-Flop chip, can emulate
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quadrature encoder signals. The clock can come from a fancy
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function generator or a cheap 555 timer chip. The clock
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frequency can be measured with another board running FreqCount
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http://www.pjrc.com/teensy/td_libs_FreqCount.html
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+5V
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| Quadrature Encoder Signal Emulator
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Clock |
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Input o----*-------------------------- ---------------------------o Output1
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| |14 | |
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| _______|_______ | | _______________
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| | CD4013 | | | | CD4013 |
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| 5 | | 1 | | 9 | | 13
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---------| D Q |-----|----*----| D Q |------o Output2
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| | | | | | |
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| | 3 | | | 11 | |
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| ----|> Clk | ---------|> Clk |
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| | | | |
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| 6 | | 8 | |
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| ----| S | ----| S |
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| | | | | | |
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| | 4 | _ | 2 | 10 | _ | 12
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| *----| R Q |--- *----| R Q |----
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| | | | | | | |
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| | |_______________| | |_______________| |
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| | | 7 | |
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--------------------------------------------------------------
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----- ----- -----
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--- --- ---
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- - -
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*/
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void setup() {
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pinMode(outputPin, OUTPUT);
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}
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#if defined(__AVR__)
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#define REGTYPE unsigned char
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#elif defined(__PIC32MX__)
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#define REGTYPE unsigned long
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#endif
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void loop() {
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volatile int count = 0;
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volatile REGTYPE *reg = portOutputRegister(digitalPinToPort(outputPin));
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REGTYPE mask = digitalPinToBitMask(outputPin);
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while (1) {
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myEnc.read(); // Read the encoder while interrupts are enabled.
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noInterrupts();
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*reg |= mask; // Pulse the pin high, while interrupts are disabled.
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count = count + 1;
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*reg &= ~mask;
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interrupts();
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}
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}
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