quadrature_encoder.pio.h

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// -------------------------------------------------- //
// This file is autogenerated by pioasm; do not edit! //
// -------------------------------------------------- //
 
#pragma once
 
#if !PICO_NO_HARDWARE
#include "hardware/pio.h"
#endif
 
// ------------------ //
// quadrature_encoder //
// ------------------ //
 
#define quadrature_encoder_wrap_target 15
#define quadrature_encoder_wrap 28
 
static const uint16_t quadrature_encoder_program_instructions[] = {
    0x000f, //  0: jmp    15                         
    0x000e, //  1: jmp    14                         
    0x001a, //  2: jmp    26                         
    0x000f, //  3: jmp    15                         
    0x001a, //  4: jmp    26                         
    0x000f, //  5: jmp    15                         
    0x000f, //  6: jmp    15                         
    0x000e, //  7: jmp    14                         
    0x000e, //  8: jmp    14                         
    0x000f, //  9: jmp    15                         
    0x000f, // 10: jmp    15                         
    0x001a, // 11: jmp    26                         
    0x000f, // 12: jmp    15                         
    0x001a, // 13: jmp    26                         
    0x008f, // 14: jmp    y--, 15                    
            //     .wrap_target
    0xe020, // 15: set    x, 0                       
    0x8080, // 16: pull   noblock                    
    0xa027, // 17: mov    x, osr                     
    0xa0e6, // 18: mov    osr, isr                   
    0x0036, // 19: jmp    !x, 22                     
    0xa0c2, // 20: mov    isr, y                     
    0x8020, // 21: push   block                      
    0xa0c3, // 22: mov    isr, null                  
    0x40e2, // 23: in     osr, 2                     
    0x4002, // 24: in     pins, 2                    
    0xa0a6, // 25: mov    pc, isr                    
    0xa02a, // 26: mov    x, !y                      
    0x005c, // 27: jmp    x--, 28                    
    0xa049, // 28: mov    y, !x                      
            //     .wrap
};
 
#if !PICO_NO_HARDWARE
static const struct pio_program quadrature_encoder_program = {
    .instructions = quadrature_encoder_program_instructions,
    .length = 29,
    .origin = 0,
};
 
static inline pio_sm_config quadrature_encoder_program_get_default_config(uint offset) {
    pio_sm_config c = pio_get_default_sm_config();
    sm_config_set_wrap(&c, offset + quadrature_encoder_wrap_target, offset + quadrature_encoder_wrap);
    return c;
}
 
#include "hardware/clocks.h"
#include "hardware/gpio.h"
// max_step_rate is used to lower the clock of the state machine to save power
// if the application doesn't require a very high sampling rate. Passing zero
// will set the clock to the maximum, which gives a max step rate of around
// 8.9 Msteps/sec at 125MHz
static inline void quadrature_encoder_program_init(PIO pio, uint sm, uint offset, uint pin, int max_step_rate)
{
    pio_sm_set_consecutive_pindirs(pio, sm, pin, 2, false);
    gpio_pull_up(pin);
    gpio_pull_up(pin + 1);
    pio_sm_config c = quadrature_encoder_program_get_default_config(offset);
    sm_config_set_in_pins(&c, pin); // for WAIT, IN
    sm_config_set_jmp_pin(&c, pin); // for JMP
    // shift to left, autopull disabled
    sm_config_set_in_shift(&c, false, false, 32);
    // don't join FIFO's
    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_NONE);
    // passing "0" as the sample frequency,
    if (max_step_rate == 0) {
        sm_config_set_clkdiv(&c, 1.0);
    } else {
        // one state machine loop takes at most 14 cycles
        float div = (float)clock_get_hz(clk_sys) / (14 * max_step_rate);
        sm_config_set_clkdiv(&c, div);
    }
    pio_sm_init(pio, sm, offset, &c);
    pio_sm_set_enabled(pio, sm, true);
}
// When requesting the current count we may have to wait a few cycles (average
// ~11 sysclk cycles) for the state machine to reply. If we are reading multiple
// encoders, we may request them all in one go and then fetch them all, thus
// avoiding doing the wait multiple times. If we are reading just one encoder,
// we can use the "get_count" function to request and wait
static inline void quadrature_encoder_request_count(PIO pio, uint sm)
{
    pio->txf[sm] = 1;
}
static inline int32_t quadrature_encoder_fetch_count(PIO pio, uint sm)
{
    while (pio_sm_is_rx_fifo_empty(pio, sm));
    return pio->rxf[sm];
}
static inline int32_t quadrature_encoder_get_count(PIO pio, uint sm)
{
    quadrature_encoder_request_count(pio, sm);
    return quadrature_encoder_fetch_count(pio, sm);
}
 
#endif