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Cleanup 3rd party samples; update README.md; add some missing copyright, fix builds for boards without certain pin definitions

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This commit is contained in:
Graham Sanderson
2021-10-28 14:56:05 -05:00
committed by GitHub
parent 1300621684
commit fa09f2c88e
16 changed files with 111 additions and 117 deletions
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50
pio/quadrature_encoder/quadrature_encoder.c
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@@ -1,3 +1,9 @@
/**
* Copyright (c) 2021 pmarques-dev @ github
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/pio.h"
@@ -13,7 +19,7 @@
// updated. At any point, the main code can query the current count by using
// the quadrature_encoder_*_count functions. The counter is kept in a full
// 32 bit register that just wraps around. Two's complement arithmetic means
// that it can be interpreted as a 32 bit signed or unsigned value and it will
// that it can be interpreted as a 32-bit signed or unsigned value, and it will
// work anyway.
//
// As an example, a two wheel robot being controlled at 100Hz, can use two
@@ -26,34 +32,30 @@
// encoder count updated and because of that it supports very high step rates.
//
int main() {
int new_value, delta, old_value = 0;
int main()
{
int new_value, delta, old_value = 0;
// Base pin to connect the A phase of the encoder.
// The B phase must be connected to the next pin
const uint PIN_AB = 10;
// Base pin to connect the A phase of the encoder.
// The B phase must be connected to the next pin
const uint PIN_AB = 10;
stdio_init_all();
stdio_init_all();
PIO pio = pio0;
const uint sm = 0;
PIO pio = pio0;
const uint sm = 0;
uint offset = pio_add_program(pio, &quadrature_encoder_program);
quadrature_encoder_program_init(pio, sm, offset, PIN_AB, 0);
uint offset = pio_add_program(pio, &quadrature_encoder_program);
quadrature_encoder_program_init(pio, sm, offset, PIN_AB, 0);
while (1) {
// note: thanks to two's complement arithmetic delta will always
// be correct even when new_value wraps around MAXINT / MININT
new_value = quadrature_encoder_get_count(pio, sm);
delta = new_value - old_value;
old_value = new_value;
while (1) {
// note: thanks to two's complement arithmetic delta will always
// be correct even when new_value wraps around MAXINT / MININT
new_value = quadrature_encoder_get_count(pio, sm);
delta = new_value - old_value;
old_value = new_value;
printf("position %8d, delta %6d\n", new_value, delta);
sleep_ms(100);
}
return 0;
printf("position %8d, delta %6d\n", new_value, delta);
sleep_ms(100);
}
}

7
pio/quadrature_encoder/quadrature_encoder.pio
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@@ -1,3 +1,8 @@
;
; Copyright (c) 2021 pmarques-dev @ github
;
; SPDX-License-Identifier: BSD-3-Clause
;
.program quadrature_encoder
@@ -6,7 +11,7 @@
.origin 0
; the code works by running a loop that contiously shifts the 2 phase pins into
; the code works by running a loop that continuously shifts the 2 phase pins into
; ISR and looks at the lower 4 bits to do a computed jump to an instruction that
; does the proper "do nothing" | "increment" | "decrement" action for that pin
; state change (or no change)