1 files changed, 41 insertions, 10 deletions

diff --git a/main/drv/ws2812b.c b/main/drv/ws2812b.c
index 3ab6b41..d0699ee 100644
--- a/main/drv/ws2812b.c
+++ b/main/drv/ws2812b.c
@@ -1,12 +1,19 @@
 #include <drv/ws2812b.h>
+#include <memory.h>
+
+#define WS2812B_FLAG_DIRTY 1
 
 struct WS2812B {
   spi_device_handle_t spi_handle;
+  spi_transaction_t spi_transaction;
+
+  uint8_t flags;
 };
 
 ws2812b_t* ws2812b_init(spi_device_handle_t spi)
 {
   ws2812b_t* ret = heap_caps_malloc(sizeof(ws2812b_t), MALLOC_CAP_DEFAULT);
+  memset(ret, 0, sizeof(*ret));
   ret->spi_handle = spi;
 
   return ret;
@@ -27,6 +34,12 @@ static inline void byte_compile(uint8_t byte, uint8_t compl [3])
 
 static inline void compile(ws2812b_buffer_t* buffer)
 {
+  if (buffer->buf_ == buffer->buf_1) {
+    buffer->buf_ = buffer->buf_2;
+  } else {
+    buffer->buf_ = buffer->buf_1;
+  }
+
   for (size_t i = 0; i < buffer->n_rgb; ++i) {
     byte_compile(buffer->rgb[i].g, buffer->buf_ + i * 9 + 0);
     byte_compile(buffer->rgb[i].r, buffer->buf_ + i * 9 + 3);
@@ -38,31 +51,49 @@ ws2812b_buffer_t* ws2812b_new_buffer(uint32_t n)
 {
   ws2812b_buffer_t* ret = heap_caps_malloc(
       sizeof(ws2812b_buffer_t) + sizeof(ws2812b_rgb_t) * n, MALLOC_CAP_DEFAULT);
-  ret->buf_ = heap_caps_malloc(n * 9, MALLOC_CAP_DMA);
+  ret->buf_1 = heap_caps_malloc(n * 9, MALLOC_CAP_DMA);
+  ret->buf_2 = heap_caps_malloc(n * 9, MALLOC_CAP_DMA);
+  ret->buf_ = ret->buf_1;
   ret->n_rgb = n;
   return ret;
 }
 
-esp_err_t ws2812b_write_sync(ws2812b_t* drv, ws2812b_buffer_t* buffer)
+esp_err_t ws2812b_wait(ws2812b_t* drv)
 {
   esp_err_t err;
 
-  compile(buffer);
-  spi_transaction_t t = {0};
   spi_transaction_t* rt;
-
-  t.tx_buffer = buffer->buf_;
-  t.length = buffer->n_rgb * 9 * 8;
-
-  err = spi_device_queue_trans(drv->spi_handle, &t, portMAX_DELAY);
+  err = spi_device_get_trans_result(
+      drv->spi_handle, &rt, 10 / portTICK_PERIOD_MS);
+  drv->flags &= ~WS2812B_FLAG_DIRTY;
   if (err != ESP_OK) {
     return err;
   }
 
-  err = spi_device_get_trans_result(drv->spi_handle, &rt, portMAX_DELAY);
+  return ESP_OK;
+}
+
+esp_err_t ws2812b_write(ws2812b_t* drv, ws2812b_buffer_t* buffer)
+{
+  compile(buffer);
+
+  if (drv->flags & WS2812B_FLAG_DIRTY) {
+    ws2812b_wait(drv);
+  }
+
+  esp_err_t err;
+
+  memset(&drv->spi_transaction, 0, sizeof(drv->spi_transaction));
+
+  drv->spi_transaction.tx_buffer = buffer->buf_;
+  drv->spi_transaction.length = buffer->n_rgb * 9 * 8;
+
+  err = spi_device_queue_trans(
+      drv->spi_handle, &drv->spi_transaction, portMAX_DELAY);
   if (err != ESP_OK) {
     return err;
   }
+  drv->flags |= WS2812B_FLAG_DIRTY;
 
   return ESP_OK;
 }