doc: explain why RMT encoder may result in more data transmitting

Closes https://github.com/espressif/esp-idf/issues/11468

components/driver/test_apps/rmt/main/test_rmt_common.c

@@ -13,7 +13,7 @@
 #include "driver/rmt_rx.h"
 #include "soc/soc_caps.h"
 
-TEST_CASE("rmt_channel_install_uninstall", "[rmt]")
+TEST_CASE("rmt channel install & uninstall", "[rmt]")
 {
     rmt_tx_channel_config_t tx_channel_cfg = {
         .mem_block_symbols = SOC_RMT_MEM_WORDS_PER_CHANNEL,

components/driver/test_apps/rmt/main/test_rmt_iram.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -78,17 +78,14 @@ static void test_rmt_tx_iram_safe(size_t mem_block_symbols, bool with_dma)
     TEST_ESP_OK(rmt_del_encoder(led_strip_encoder));
 }
 
-TEST_CASE("rmt_tx_iram_safe_no_dma", "[rmt]")
+TEST_CASE("rmt tx iram safe", "[rmt]")
 {
     test_rmt_tx_iram_safe(SOC_RMT_MEM_WORDS_PER_CHANNEL, false);
+#if SOC_RMT_SUPPORT_DMA
+    test_rmt_tx_iram_safe(1024, true);
+#endif
 }
 
-#if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_tx_iram_safe_with_dma", "[rmt]")
-{
-    test_rmt_tx_iram_safe(1024, true);
-}
-#endif
 
 
 static void IRAM_ATTR test_simulate_input_post_cache_disable(void *args)
@@ -169,14 +166,10 @@ static void test_rmt_rx_iram_safe(size_t mem_block_symbols, bool with_dma, rmt_c
     TEST_ESP_OK(rmt_del_channel(rx_channel));
 }
 
-TEST_CASE("rmt_rx_iram_safe_no_dma", "[rmt]")
+TEST_CASE("rmt rx iram safe", "[rmt]")
 {
     test_rmt_rx_iram_safe(SOC_RMT_MEM_WORDS_PER_CHANNEL, false, RMT_CLK_SRC_DEFAULT);
-}
-
 #if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_rx_iram_safe_with_dma", "[rmt]")
-{
     test_rmt_rx_iram_safe(128, true, RMT_CLK_SRC_DEFAULT);
-}
 #endif
+}

components/driver/test_apps/rmt/main/test_rmt_rx.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -185,18 +185,14 @@ static void test_rmt_rx_nec_carrier(size_t mem_block_symbols, bool with_dma, rmt
     TEST_ESP_OK(rmt_del_encoder(nec_encoder));
 }
 
-TEST_CASE("rmt_rx_nec_carrier_no_dma", "[rmt]")
+TEST_CASE("rmt rx nec with carrier", "[rmt]")
 {
     // test width different clock sources
     rmt_clock_source_t clk_srcs[] = SOC_RMT_CLKS;
     for (size_t i = 0; i < sizeof(clk_srcs) / sizeof(clk_srcs[0]); i++) {
         test_rmt_rx_nec_carrier(SOC_RMT_MEM_WORDS_PER_CHANNEL, false, clk_srcs[i]);
     }
-}
-
 #if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_rx_nec_carrier_with_dma", "[rmt]")
-{
     test_rmt_rx_nec_carrier(128, true, RMT_CLK_SRC_DEFAULT);
-}
 #endif
+}

components/driver/test_apps/rmt/main/test_rmt_tx.c

@@ -20,6 +20,63 @@
 #define TEST_RMT_CALLBACK_ATTR
 #endif
 
+TEST_CASE("rmt bytes encoder", "[rmt]")
+{
+    rmt_tx_channel_config_t tx_channel_cfg = {
+        .mem_block_symbols = SOC_RMT_MEM_WORDS_PER_CHANNEL,
+        .clk_src = RMT_CLK_SRC_DEFAULT,
+        .resolution_hz = 1000000, // 1MHz, 1 tick = 1us
+        .trans_queue_depth = 4,
+        .gpio_num = 0,
+    };
+    printf("install tx channel\r\n");
+    rmt_channel_handle_t tx_channel = NULL;
+    TEST_ESP_OK(rmt_new_tx_channel(&tx_channel_cfg, &tx_channel));
+    printf("install bytes encoder\r\n");
+    rmt_encoder_handle_t bytes_encoder = NULL;
+    rmt_bytes_encoder_config_t bytes_enc_config = {
+        .bit0 = {
+            .level0 = 1,
+            .duration0 = 3, // 3us
+            .level1 = 0,
+            .duration1 = 9, // 9us
+        },
+        .bit1 = {
+            .level0 = 1,
+            .duration0 = 9, // 9us
+            .level1 = 0,
+            .duration1 = 3, // 3us
+        },
+    };
+    TEST_ESP_OK(rmt_new_bytes_encoder(&bytes_enc_config, &bytes_encoder));
+    printf("enable tx channel\r\n");
+    TEST_ESP_OK(rmt_enable(tx_channel));
+
+    printf("start transaction\r\n");
+    rmt_transmit_config_t transmit_config = {
+        .loop_count = 0, // no loop
+    };
+    TEST_ESP_OK(rmt_transmit(tx_channel, bytes_encoder, (uint8_t[]) {
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05
+    }, 6, &transmit_config));
+    // adding extra delay here for visualizing
+    vTaskDelay(pdMS_TO_TICKS(500));
+    TEST_ESP_OK(rmt_transmit(tx_channel, bytes_encoder, (uint8_t[]) {
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06
+    }, 7, &transmit_config));
+    vTaskDelay(pdMS_TO_TICKS(500));
+    TEST_ESP_OK(rmt_transmit(tx_channel, bytes_encoder, (uint8_t[]) {
+        0x00, 0x01, 0x02, 0x03, 0x04
+    }, 5, &transmit_config));
+    vTaskDelay(pdMS_TO_TICKS(500));
+
+    printf("disable tx channel\r\n");
+    TEST_ESP_OK(rmt_disable(tx_channel));
+    printf("remove tx channel and encoder\r\n");
+    TEST_ESP_OK(rmt_del_channel(tx_channel));
+    TEST_ESP_OK(rmt_del_encoder(bytes_encoder));
+}
+
 static void test_rmt_channel_single_trans(size_t mem_block_symbols, bool with_dma)
 {
     rmt_tx_channel_config_t tx_channel_cfg = {
@@ -66,17 +123,13 @@ static void test_rmt_channel_single_trans(size_t mem_block_symbols, bool with_dm
     TEST_ESP_OK(rmt_del_encoder(led_strip_encoder));
 }
 
-TEST_CASE("rmt_single_trans_no_dma", "[rmt]")
+TEST_CASE("rmt single transaction", "[rmt]")
 {
     test_rmt_channel_single_trans(SOC_RMT_MEM_WORDS_PER_CHANNEL, false);
-}
-
 #if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_single_trans_with_dma", "[rmt]")
-{
     test_rmt_channel_single_trans(512, true);
-}
 #endif
+}
 
 static void test_rmt_ping_pong_trans(size_t mem_block_symbols, bool with_dma)
 {
@@ -147,17 +200,14 @@ static void test_rmt_ping_pong_trans(size_t mem_block_symbols, bool with_dma)
 #undef TEST_LED_NUM
 }
 
-TEST_CASE("rmt_ping_pong_trans_no_dma", "[rmt]")
+TEST_CASE("rmt ping-pong transaction", "[rmt]")
 {
     test_rmt_ping_pong_trans(SOC_RMT_MEM_WORDS_PER_CHANNEL, false);
+#if SOC_RMT_SUPPORT_DMA
+    test_rmt_ping_pong_trans(1024, true);
+#endif
 }
 
-#if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_ping_pong_trans_with_dma", "[rmt]")
-{
-    test_rmt_ping_pong_trans(1024, true);
-}
-#endif
 
 TEST_RMT_CALLBACK_ATTR
 static bool test_rmt_tx_done_cb_check_event_data(rmt_channel_handle_t channel, const rmt_tx_done_event_data_t *edata, void *user_data)
@@ -222,17 +272,13 @@ static void test_rmt_trans_done_event(size_t mem_block_symbols, bool with_dma)
 #undef TEST_LED_NUM
 }
 
-TEST_CASE("rmt_trans_done_event_callback_no_dma", "[rmt]")
+TEST_CASE("rmt trans_done event callback", "[rmt]")
 {
     test_rmt_trans_done_event(SOC_RMT_MEM_WORDS_PER_CHANNEL, false);
-}
-
 #if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_trans_done_event_callback_with_dma", "[rmt]")
-{
     test_rmt_trans_done_event(332, true);
-}
 #endif
+}
 
 #if SOC_RMT_SUPPORT_TX_LOOP_COUNT
 
@@ -294,20 +340,17 @@ static void test_rmt_loop_trans(size_t mem_block_symbols, bool with_dma)
 #undef TEST_LED_NUM
 }
 
-TEST_CASE("rmt_loop_trans_no_dma", "[rmt]")
+TEST_CASE("rmt finite loop transaction", "[rmt]")
 {
     test_rmt_loop_trans(SOC_RMT_MEM_WORDS_PER_CHANNEL * 2, false);
+#if SOC_RMT_SUPPORT_DMA
+    test_rmt_loop_trans(128, true);
+#endif
 }
 
-#if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_loop_trans_with_dma", "[rmt]")
-{
-    test_rmt_loop_trans(128, true);
-}
-#endif // SOC_RMT_SUPPORT_DMA
 #endif // SOC_RMT_SUPPORT_TX_LOOP_COUNT
 
-TEST_CASE("rmt_infinite_loop_trans", "[rmt]")
+TEST_CASE("rmt infinite loop transaction", "[rmt]")
 {
     rmt_tx_channel_config_t tx_channel_cfg = {
         .clk_src = RMT_CLK_SRC_DEFAULT,
@@ -441,17 +484,14 @@ static void test_rmt_tx_nec_carrier(size_t mem_block_symbols, bool with_dma)
     TEST_ESP_OK(rmt_del_encoder(nec_encoder));
 }
 
-TEST_CASE("rmt_tx_nec_carrier_no_dma", "[rmt]")
+TEST_CASE("rmt tx nec with carrier", "[rmt]")
 {
     test_rmt_tx_nec_carrier(SOC_RMT_MEM_WORDS_PER_CHANNEL, false);
+#if SOC_RMT_SUPPORT_DMA
+    test_rmt_tx_nec_carrier(128, true);
+#endif
 }
 
-#if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_tx_nec_carrier_with_dma", "[rmt]")
-{
-    test_rmt_tx_nec_carrier(128, true);
-}
-#endif
 
 TEST_RMT_CALLBACK_ATTR
 static bool test_rmt_tx_done_cb_record_time(rmt_channel_handle_t channel, const rmt_tx_done_event_data_t *edata, void *user_data)
@@ -596,14 +636,10 @@ static void test_rmt_multi_channels_trans(size_t channel0_mem_block_symbols, siz
 #undef TEST_RMT_CHANS
 }
 
-TEST_CASE("rmt_multi_channels_trans_no_dma", "[rmt]")
+TEST_CASE("rmt multiple channels transaction", "[rmt]")
 {
     test_rmt_multi_channels_trans(SOC_RMT_MEM_WORDS_PER_CHANNEL, SOC_RMT_MEM_WORDS_PER_CHANNEL, false, false);
-}
-
 #if SOC_RMT_SUPPORT_DMA
-TEST_CASE("rmt_multi_channels_trans_with_dma", "[rmt]")
-{
     test_rmt_multi_channels_trans(1024, SOC_RMT_MEM_WORDS_PER_CHANNEL, true, false);
-}
 #endif
+}