From 3bbb76672a4ec76e1b2043cb2f4f29ea098caf02 Mon Sep 17 00:00:00 2001
From: Pavel Brychta <pavel.brychta@post.cz>
Date: Fri, 4 Sep 2020 11:21:26 +0200
Subject: [PATCH] Pouziti RMT periferie pro ESP32

---
 src/wsLED.cpp | 63 +++++++++++++++++++++++++++++++++++++++++----------
 src/wsLED.h   |  3 +++
 2 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/src/wsLED.cpp b/src/wsLED.cpp
index 0e735f3..fab08c4 100644
--- a/src/wsLED.cpp
+++ b/src/wsLED.cpp
@@ -1,11 +1,25 @@
 // Ovladani signalizacni chytre LED diody
 #include "wsLED.h"
-//#if defined(ARDUINO_ARCH_ESP32)
+#if defined(ARDUINO_ARCH_ESP32)
 //# include "esp_task.h"
-//#endif
+// https://github.com/JSchaenzle/ESP32-NeoPixel-WS2812-RMT/blob/master/ws2812_control.c
+#  include <driver/rmt.h>
+#  include <set>
+#  ifndef LED_RMT_TX_CHANNEL
+#    define LED_RMT_TX_CHANNEL RMT_CHANNEL_0
+#  endif
+#  define BITS_PER_LED_CMD 24
+#  define LED_BUFFER_ITEMS ((1 * BITS_PER_LED_CMD))
+// These values are determined by measuring pulse timing with logic analyzer and adjusting to match datasheet.
+#  define T0H 14  // 0 bit high time
+#  define T1H 52  // 1 bit high time
+#  define TL  52  // low time for either bit
+#endif
+#if defined(ARDUINO_ARCH_ESP8266)
 // due to linker overriding the ICACHE_RAM_ATTR for cpp files, these methods are
 // moved into a C file so the attribute will be applied correctly
 extern "C" void ICACHE_RAM_ATTR send_pixels_800(uint8_t* pixel, size_t count, uint8_t pin);
+#endif
 
 #define countof(a) (sizeof(a) / sizeof(a[0]))
 
@@ -35,16 +49,20 @@ void wsLED::show(void)
     while (!canShow())
         __asm__ volatile ("nop");
 #if defined(ARDUINO_ARCH_ESP32)
-//    uint32_t volatile register ilevel = XTOS_DISABLE_ALL_INTERRUPTS;
-    portENTER_CRITICAL(&_mux);
+    rmt_item32_t led_data_buffer[LED_BUFFER_ITEMS];
+
+    uint32_t bits_to_send = ((uint32_t)color[0] << 16) | ((uint32_t)color[1] << 8) | (uint32_t)color[2];
+    uint32_t mask = 1 << (BITS_PER_LED_CMD - 1);
+    for (uint32_t bit = 0; bit < BITS_PER_LED_CMD; bit++) {
+        uint32_t bit_is_set = bits_to_send & mask;
+        led_data_buffer[bit] = bit_is_set ? (rmt_item32_t) {{{T1H, 1, TL, 0}}} : (rmt_item32_t) {{{T0H, 1, TL, 0}}};
+        mask >>= 1;
+    }
+    ESP_ERROR_CHECK(rmt_write_items(LED_RMT_TX_CHANNEL, led_data_buffer, LED_BUFFER_ITEMS, false));
+    ESP_ERROR_CHECK(rmt_wait_tx_done(LED_RMT_TX_CHANNEL, portMAX_DELAY));
 #else
     noInterrupts();
-#endif
     send_pixels_800(color, 1, _pin);
-#if defined(ARDUINO_ARCH_ESP32)
-//    XTOS_RESTORE_INTLEVEL(ilevel);
-    portEXIT_CRITICAL(&_mux);
-#else
     interrupts();
 #endif
     _endtime = micros();
@@ -61,9 +79,28 @@ wsLED::wsLED(int pin, int order)
 void wsLED::begin(void)
 {
 
-  pinMode(_pin, OUTPUT);
-  _color[0] = _color[1] = _color[2] = 0;
-  show();
+#if defined(ARDUINO_ARCH_ESP8266)
+    pinMode(_pin, OUTPUT);
+#endif
+#if defined(ARDUINO_ARCH_ESP32)
+// TODO: mozna nejak zkusit najit volny RMT kanal?
+    rmt_config_t config;
+
+    config.rmt_mode = RMT_MODE_TX;
+    config.channel = LED_RMT_TX_CHANNEL;
+    config.gpio_num = (gpio_num_t)_pin;
+    config.mem_block_num = 3;
+    config.tx_config.loop_en = false;
+    config.tx_config.carrier_en = false;
+    config.tx_config.idle_output_en = true;
+    config.tx_config.idle_level = RMT_IDLE_LEVEL_LOW;
+    config.clk_div = 2;
+
+    ESP_ERROR_CHECK(rmt_config(&config));
+    ESP_ERROR_CHECK(rmt_driver_install(config.channel, 0, 0));
+#endif
+    _color[0] = _color[1] = _color[2] = 0;
+    show();
 }
 
 void wsLED::setColor(LEDRGB &color)
@@ -146,3 +183,5 @@ void wsLED::setOrder(int neworder)
 
     _order = neworder;
 }
+
+
diff --git a/src/wsLED.h b/src/wsLED.h
index 3590e09..781db78 100644
--- a/src/wsLED.h
+++ b/src/wsLED.h
@@ -131,6 +131,9 @@ protected:
         LED_PATTERN,
     } _ledState; // stav LEDky (blika, dycha, ...)
     int _subState; // pomocny stav/index v poli dychani
+#if defined(ARDUINO_ARCH_ESP32)
+    int _rmtChannel;
+#endif
 
     bool canShow(void);
     void show(void);