Cameron/pico-examples
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

PIO WS2812 Sample: Change 'string' to 'strip' (#279)

Browse Source
This commit is contained in:
Henry Gabryjelski
2023-02-02 11:03:43 -08:00
committed by GitHub
parent a7ad17156b
commit f6ac6f5b49
1 changed files with 37 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

74
pio/ws2812/ws2812_parallel.c
View File

@@ -20,15 +20,15 @@
#define WS2812_PIN_BASE 2
// horrible temporary hack to avoid changing pattern code
static uint8_t *current_string_out;
static bool current_string_4color;
static uint8_t *current_strip_out;
static bool current_strip_4color;
static inline void put_pixel(uint32_t pixel_grb) {
*current_string_out++ = pixel_grb & 0xffu;
*current_string_out++ = (pixel_grb >> 8u) & 0xffu;
*current_string_out++ = (pixel_grb >> 16u) & 0xffu;
if (current_string_4color) {
*current_string_out++ = 0; // todo adjust?
*current_strip_out++ = pixel_grb & 0xffu;
*current_strip_out++ = (pixel_grb >> 8u) & 0xffu;
*current_strip_out++ = (pixel_grb >> 16u) & 0xffu;
if (current_strip_4color) {
*current_strip_out++ = 0; // todo adjust?
}
}
@@ -83,9 +83,9 @@ void pattern_solid(uint len, uint t) {
}
}
int level = 8;
void pattern_fade(uint len, uint t) {
const int level = 8;
uint shift = 4;
uint max = 16; // let's not draw too much current!
@@ -95,7 +95,7 @@ void pattern_fade(uint len, uint t) {
slow_t = level;
slow_t %= max;
static int error;
static int error = 0;
slow_t += error;
error = slow_t & ((1u << shift) - 1);
slow_t >>= shift;
@@ -121,7 +121,7 @@ const struct {
#define VALUE_PLANE_COUNT (8 + FRAC_BITS)
// we store value (8 bits + fractional bits of a single color (R/G/B/W) value) for multiple
// strings, in bit planes. bit plane N has the Nth bit of each string.
// strips of pixels, in bit planes. bit plane N has the Nth bit of each strip of pixels.
typedef struct {
// stored MSB first
uint32_t planes[VALUE_PLANE_COUNT];
@@ -149,17 +149,17 @@ typedef struct {
uint8_t *data;
uint data_len;
uint frac_brightness; // 256 = *1.0;
} string_t;
} strip_t;
// takes 8 bit color values, multiply by brightness and store in bit planes
void transform_strings(string_t **strings, uint num_strings, value_bits_t *values, uint value_length,
void transform_strips(strip_t **strips, uint num_strips, value_bits_t *values, uint value_length,
uint frac_brightness) {
for (uint v = 0; v < value_length; v++) {
memset(&values[v], 0, sizeof(values[v]));
for (int i = 0; i < num_strings; i++) {
if (v < strings[i]->data_len) {
for (int i = 0; i < num_strips; i++) {
if (v < strips[i]->data_len) {
// todo clamp?
uint32_t value = (strings[i]->data[v] * strings[i]->frac_brightness) >> 8u;
uint32_t value = (strips[i]->data[v] * strips[i]->frac_brightness) >> 8u;
value = (value * frac_brightness) >> 8u;
for (int j = 0; j < VALUE_PLANE_COUNT && value; j++, value >>= 1u) {
if (value & 1u) values[v].planes[VALUE_PLANE_COUNT - 1 - j] |= 1u << i;
@@ -177,29 +177,29 @@ void dither_values(const value_bits_t *colors, value_bits_t *state, const value_
// requested colors * 4 to allow for RGBW
static value_bits_t colors[NUM_PIXELS * 4];
// double buffer the state of the string, since we update next version in parallel with DMAing out old version
// double buffer the state of the pixel strip, since we update next version in parallel with DMAing out old version
static value_bits_t states[2][NUM_PIXELS * 4];
// example - string 0 is RGB only
static uint8_t string0_data[NUM_PIXELS * 3];
// example - string 1 is RGBW
static uint8_t string1_data[NUM_PIXELS * 4];
// example - strip 0 is RGB only
static uint8_t strip0_data[NUM_PIXELS * 3];
// example - strip 1 is RGBW
static uint8_t strip1_data[NUM_PIXELS * 4];
string_t string0 = {
.data = string0_data,
.data_len = sizeof(string0_data),
strip_t strip0 = {
.data = strip0_data,
.data_len = sizeof(strip0_data),
.frac_brightness = 0x40,
};
string_t string1 = {
.data = string1_data,
.data_len = sizeof(string1_data),
strip_t strip1 = {
.data = strip1_data,
.data_len = sizeof(strip1_data),
.frac_brightness = 0x100,
};
string_t *strings[] = {
&string0,
&string1,
strip_t *strips[] = {
&strip0,
&strip1,
};
// bit plane content dma channel
@@ -266,7 +266,7 @@ void dma_init(PIO pio, uint sm) {
irq_set_enabled(DMA_IRQ_0, true);
}
void output_strings_dma(value_bits_t *bits, uint value_length) {
void output_strips_dma(value_bits_t *bits, uint value_length) {
for (uint i = 0; i < value_length; i++) {
fragment_start[i] = (uintptr_t) bits[i].planes; // MSB first
}
@@ -285,7 +285,7 @@ int main() {
int sm = 0;
uint offset = pio_add_program(pio, &ws2812_parallel_program);
ws2812_parallel_program_init(pio, sm, offset, WS2812_PIN_BASE, count_of(strings), 800000);
ws2812_parallel_program_init(pio, sm, offset, WS2812_PIN_BASE, count_of(strips), 800000);
sem_init(&reset_delay_complete_sem, 1, 1); // initially posted so we don't block first time
dma_init(pio, sm);
@@ -299,17 +299,17 @@ int main() {
int brightness = 0;
uint current = 0;
for (int i = 0; i < 1000; ++i) {
current_string_out = string0.data;
current_string_4color = false;
current_strip_out = strip0.data;
current_strip_4color = false;
pattern_table[pat].pat(NUM_PIXELS, t);
current_string_out = string1.data;
current_string_4color = true;
current_strip_out = strip1.data;
current_strip_4color = true;
pattern_table[pat].pat(NUM_PIXELS, t);
transform_strings(strings, count_of(strings), colors, NUM_PIXELS * 4, brightness);
transform_strips(strips, count_of(strips), colors, NUM_PIXELS * 4, brightness);
dither_values(colors, states[current], states[current ^ 1], NUM_PIXELS * 4);
sem_acquire_blocking(&reset_delay_complete_sem);
output_strings_dma(states[current], NUM_PIXELS * 4);
output_strips_dma(states[current], NUM_PIXELS * 4);
current ^= 1;
t += dir;