Add asynchronous DMA support and fix timing issues

main/leds.cpp

@@ -37,8 +37,19 @@ void Pattern::step(Color pixels[], int len, int64_t &last_us, Fixed &offset) con
     last_us = now_us;
     //ESP_LOGI(TAG, "duration %d", duration_us);
 
+    /*
+    int period_us = 1000000 / 60;
+    int n_skipped = (duration_us - period_us / 2) / period_us;
+    if (n_skipped) {
+        ESP_LOGW(TAG, "Skipped %d frames", n_skipped);
+    }
+    */
+    // Don't make a major animation jump if it's been terribly long
+    if (duration_us > 100000) duration_us = 100000;
+
+
     int offset_delta = (duration_us << shift) / (cycle_time_ms * 1000);
-    if (reverse) offset -= offset_delta; else offset += offset_delta;
+    if (reverse) offset += offset_delta; else offset -= offset_delta;
     Fixed off = march ?
             (((int)offset * cycle_length) & ~((1 << shift) - 1)) / cycle_length :
             offset;
@@ -73,7 +84,7 @@ static std::string termcolor(Color c) {
             std::to_string((int)c.b) + "m";
 }
 
-void TerminalLEDs::show() const {
+void TerminalLEDs::show() {
     std::string line;
     for (int i = 0; i < length; i++) {
         line += termcolor(pixels[i]) + " ";

main/leds.hpp

@@ -36,7 +36,7 @@ public:
 
     void step();
 
-    virtual void show() const = 0;
+    virtual void show() = 0;
     virtual void length_changing(int) {};
 
     void setPattern(const Pattern *_pattern) { pattern = _pattern; }
@@ -58,5 +58,5 @@ private:
 class TerminalLEDs : public LEDStrip {
 public:
     TerminalLEDs(int length = 0) : LEDStrip(length) {}
-    void show() const;
+    void show();
 };

main/main.cpp

@@ -131,6 +131,7 @@ std::string gen_config(bool is_on, const std::string &effect) {
 
 constexpr char config_path[] = "/spiffs/blinky.json";
 
+//#define PROFILE
 
 // Entry Point
 
@@ -214,16 +215,16 @@ extern "C" void app_main(void) {
             int period_us = 1000000 / 60;
             int64_t start = time_us();
             int64_t target_us = start;
-/*
+#ifdef PROFILE
             int64_t total_delay_us = 0;
             int n_delays = 0;
             int64_t after_sleep_us = 0;
             int n_processes = 0;
             int64_t total_process_us = 0;
-*/
+#endif // PROFILE
             while (true) {
                 int64_t now = time_us();
-/*
+#ifdef PROFILE
                 if (after_sleep_us > 0) {
                     total_process_us += now - after_sleep_us;
                     ++n_processes;
@@ -240,23 +241,23 @@ extern "C" void app_main(void) {
 
                     start = now;
                 }
-*/
+#endif // PROFILE
                 int64_t delay_us = target_us - now;
                 if (delay_us < 0) delay_us = 0;
                 if (device.wait(delay_us / 1000)) {
                     // If the semaphore is set, go back to top of outer loop
                     break;
                 }
-/*
+
+                target_us = now + delay_us + period_us;
+#ifdef PROFILE
                 after_sleep_us = time_us();
 
                 total_delay_us += (after_sleep_us - now);
                 ++n_delays;
-*/
+#endif // PROFILE
                 LEDs->step();
                 LEDs->show();
-
-                target_us += period_us;
             }
         }
     }

main/spi_leds.cpp

@@ -16,7 +16,8 @@ static const char *TAG = "spi_leds";
 SPI_LEDs::SPI_LEDs(int _gpio, int length) :
             LEDStrip(length),
             host(SPI3_HOST), gpio(_gpio), device(NULL),
-            out_buf(NULL) {
+            out_buf(NULL)
+        {
     int ret;
 
     spi_bus_config_t buscfg = {
@@ -53,7 +54,7 @@ SPI_LEDs::SPI_LEDs(int _gpio, int length) :
         .cs_ena_posttrans = 0, // moot
         // Datasheet implies 3.2 MHz => 1.25 us / 4
         // We can get away with 4.4_ MHz => 900 ns / 4
-        .clock_speed_hz = 4444444,
+        .clock_speed_hz = 3200000,
         .input_delay_ns = 0, // moot
         .spics_io_num = -1,
         .flags = 0, // Keep it MSB first
@@ -77,6 +78,19 @@ void SPI_LEDs::configure(int len) {
     if (len <= 0) return;
 
     out_buf = (uint8_t*)heap_caps_malloc(tx_len(len), MALLOC_CAP_DMA);
+
+    memset(out_buf + tx_len(len) - reset_bytes, 0, reset_bytes);
+
+    transaction = {
+        .flags = 0,
+        .cmd = 0,
+        .addr = 0,
+        .length = tx_len(len) * 8,
+        .rxlength = 0,
+        .user = NULL,
+        .tx_buffer = out_buf,
+        .rx_buffer = NULL,
+    };
 }
 
 // Inverted
@@ -92,7 +106,8 @@ static uint8_t* encode_byte(uint8_t *out, uint8_t in) {
     return out;
 }
 
-void SPI_LEDs::show() const {
+void SPI_LEDs::show() {
+    static int index = 0;
     int ret;
     const Color *pixel = pixels;
     uint8_t *out = out_buf;
@@ -104,24 +119,24 @@ void SPI_LEDs::show() const {
         ++pixel;
     }
 
-    // TODO: Reset pad?  Or should we check clocks?
-
-    spi_transaction_ext_t transaction_ext = {
-        .base = {
-            .flags = 0,
-            .cmd = 0,
-            .addr = 0,
-            .length = tx_len(length) * 8,
-            .rxlength = 0,
-            .user = NULL,
-            .tx_buffer = out_buf,
-            .rx_buffer = NULL,
-        },
-        .command_bits = 160,
-        .address_bits = 0,
-        .dummy_bits = 160,
-    };
+    ++index;
 
-    ret = spi_device_transmit(device, &transaction_ext.base);
-    RET_ON_ERR(spi_device_transmit, ret);
+    ret = spi_device_queue_trans(device, &transaction, portMAX_DELAY);
+    RET_ON_ERR(spi_device_queue_trans, ret);
+
+/*
+    while ((ret = spi_device_queue_trans(device, &transaction, 0)) != ESP_OK) {
+        if (ret == ESP_ERR_TIMEOUT) {
+            // Wait for the previous transaction to finish
+            ESP_LOGI(TAG, "SPI transaction collision (# %d)", index);
+            spi_transaction_t *ret_trans;
+            ret = spi_device_get_trans_result(device, &ret_trans, portMAX_DELAY);
+            RET_ON_ERR(spi_device_get_trans_result, ret);
+            ESP_LOGI(TAG, "Transaction complete (# %d)", index);
+
+        } else {
+            RET_ON_ERR(spi_device_queue_trans, ret);
+        }
+    }
+*/
 }

main/spi_leds.hpp

@@ -8,7 +8,7 @@
 class SPI_LEDs : public LEDStrip {
 public:
     SPI_LEDs(int gpio, int length = 0);
-    void show() const;
+    void show();
     void length_changing(int len) { configure(len); }
 
 private:
@@ -16,8 +16,10 @@ private:
     int gpio;
     spi_device_handle_t device;
     uint8_t *out_buf;
+    spi_transaction_t transaction;
 
-    static size_t tx_len(int len) { return (len * 3) * 4; }
+    static constexpr int reset_bytes = 30;
+    static size_t tx_len(int len) { return (len * 3) * 4 + reset_bytes; }
 
     void configure(int length);
 };

main/utils.cpp

@@ -4,7 +4,10 @@
 
 
 int64_t time_us() {
-    struct timeval tv_now;
+    /*struct timeval tv_now;
     gettimeofday(&tv_now, NULL);
-    return (int64_t)tv_now.tv_sec * 1000000L + (int64_t)tv_now.tv_usec;
+    return (int64_t)tv_now.tv_sec * 1000000L + (int64_t)tv_now.tv_usec;*/
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return (int64_t)ts.tv_sec * 1000000L + (int64_t)ts.tv_nsec / 1000L;
 }