drive build in led

.gitignore

@@ -1,3 +1,2 @@
 
 /build
-

CMakeLists.txt

@@ -4,17 +4,23 @@ cmake_minimum_required(VERSION 3.13)
 # note: this must happen before project()
 include(libs/pico-sdk/pico_sdk_init.cmake)
 
-project(my_project)
+project(stofzuiger CXX C ASM)
+
+set(PICO_CXX_ENABLE_EXCEPTIONS 1)
+set(PICO_CXX_ENABLE_RTTI 1)
 
 # initialize the Raspberry Pi Pico SDK
 pico_sdk_init()
 
-add_executable(my_project
-    src/main.c
-)
+add_executable(stofzuiger src/main.c)
 
-# Add pico_stdlib library which aggregates commonly used features
-target_link_libraries(my_project pico_stdlib)
+# pico_generate_pio_header(stofzuiger ${CMAKE_CURRENT_LIST_DIR}/src/ws2812.pio)
+pico_generate_pio_header(stofzuiger ${CMAKE_CURRENT_LIST_DIR}/src/ws2812.pio OUTPUT_DIR ${CMAKE_CURRENT_LIST_DIR}/src/generated)
+
+target_link_libraries(stofzuiger pico_stdlib hardware_pio)
+
+pico_enable_stdio_uart(stofzuiger 0)
+pico_enable_stdio_usb(stofzuiger 1)
 
 # create map/bin/hex/uf2 file in addition to ELF.
-pico_add_extra_outputs(my_project)
+pico_add_extra_outputs(stofzuiger)

libs/pico-sdk

@@ -0,0 +1 @@
+Subproject commit 95ea6acad131124694cda1c162c52cd30e0aece0

src/generated/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

src/main.c

@@ -1,36 +1,50 @@
 #include <stdio.h>
-#include "pico/stdlib.h"
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
 
-// pin rgb led on Seeed XIAO RP2040
-#define PIN_RGB_R 17
-#define PIN_RGB_G 16
-#define PIN_RGB_B 25
+#include <pico/stdlib.h>
+#include <hardware/pio.h>
+#include <hardware/clocks.h>
+#include "generated/ws2812.pio.h"
 
-int main() {
-  setup_default_uart();
-  printf("Hello, world!\n");
+#define IS_RGBW false
+#define NUM_PIXELS 1
+#define WS2812_PIN 16
 
-  gpio_init(PIN_RGB_R);
-  gpio_set_dir(PIN_RGB_R, GPIO_OUT);
-  gpio_init(PIN_RGB_G);
-  gpio_set_dir(PIN_RGB_G, GPIO_OUT);
-  gpio_init(PIN_RGB_B);
-  gpio_set_dir(PIN_RGB_B, GPIO_OUT);
-  while (true)
-  {
-    gpio_put(PIN_RGB_G, 1);
-    sleep_ms(250);
-    gpio_put(PIN_RGB_R, 0);
-    sleep_ms(250);
-    gpio_put(PIN_RGB_B, 1);
-    sleep_ms(250);
-    gpio_put(PIN_RGB_G, 0);
-    sleep_ms(250);
-    gpio_put(PIN_RGB_R, 1);
-    sleep_ms(250);
-    gpio_put(PIN_RGB_B, 0);
-    sleep_ms(250);
-  }
-  return 0;
+static inline void put_pixel(PIO pio, uint sm, uint32_t pixel_grb) {
+    pio_sm_put_blocking(pio, sm, pixel_grb << 8u);
 }
 
+static inline uint32_t urgb_u32(uint8_t r, uint8_t g, uint8_t b) {
+    return ((uint32_t) (r) << 8) | ((uint32_t) (g) << 16) | (uint32_t) (b);
+}
+
+int main() {
+    //set_sys_clock_48();
+    stdio_init_all();
+    printf("WS2812 test %d\n", WS2812_PIN);
+
+    // todo get free sm
+    PIO pio;
+    uint sm;
+    uint offset;
+
+    // This will find a free pio and state machine for our program and load it for us
+    // We use pio_claim_free_sm_and_add_program_for_gpio_range (for_gpio_range variant)
+    // so we will get a PIO instance suitable for addressing gpios >= 32 if needed and supported by the hardware
+    bool success = pio_claim_free_sm_and_add_program_for_gpio_range(&ws2812_program, &pio, &sm, &offset, WS2812_PIN, 1, false);
+    if (success == false)
+    {
+        printf("Faild to claim PIO or SM");
+        return -1;
+    }
+    ws2812_program_init(pio, sm, offset, WS2812_PIN, 800000, false);
+
+    put_pixel(pio, sm, urgb_u32(50, 50, 50));
+
+    // This will free resources and unload our program
+    pio_remove_program_and_unclaim_sm(&ws2812_program, pio, sm, offset);
+
+    return 0;
+}

src/ws2812.pio

@@ -0,0 +1,53 @@
+;
+; Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+;
+; SPDX-License-Identifier: BSD-3-Clause
+;
+.pio_version 0 // only requires PIO version 0
+
+.program ws2812
+.side_set 1
+
+; The following constants are selected for broad compatibility with WS2812,
+; WS2812B, and SK6812 LEDs. Other constants may support higher bandwidths for
+; specific LEDs, such as (7,10,8) for WS2812B LEDs.
+
+.define public T1 3
+.define public T2 3
+.define public T3 4
+
+.lang_opt python sideset_init = pico.PIO.OUT_HIGH
+.lang_opt python out_init     = pico.PIO.OUT_HIGH
+.lang_opt python out_shiftdir = 1
+
+.wrap_target
+bitloop:
+    out x, 1       side 0 [T3 - 1] ; Side-set still takes place when instruction stalls
+    jmp !x do_zero side 1 [T1 - 1] ; Branch on the bit we shifted out. Positive pulse
+do_one:
+    jmp  bitloop   side 1 [T2 - 1] ; Continue driving high, for a long pulse
+do_zero:
+    nop            side 0 [T2 - 1] ; Or drive low, for a short pulse
+.wrap
+
+% c-sdk {
+#include "hardware/clocks.h"
+
+static inline void ws2812_program_init(PIO pio, uint sm, uint offset, uint pin, float freq, bool rgbw) {
+
+    pio_gpio_init(pio, pin);
+    pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
+
+    pio_sm_config c = ws2812_program_get_default_config(offset);
+    sm_config_set_sideset_pins(&c, pin);
+    sm_config_set_out_shift(&c, false, true, rgbw ? 32 : 24);
+    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+
+    int cycles_per_bit = ws2812_T1 + ws2812_T2 + ws2812_T3;
+    float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
+    sm_config_set_clkdiv(&c, div);
+
+    pio_sm_init(pio, sm, offset, &c);
+    pio_sm_set_enabled(pio, sm, true);
+}
+%}