move to new esp rmt device driver: resolves DavidAntliff#28

include/owb.h

@@ -125,23 +125,17 @@ typedef enum
 /** NOTE: Driver assumes that (*init) was called prior to any other methods */
 struct owb_driver
 {
-    /** Driver identification **/
     const char* name;
-
-    /** Pointer to driver uninitialization function **/
     owb_status (*uninitialize)(const OneWireBus * bus);
-
-    /** Pointer to driver reset functio **/
-    owb_status (*reset)(const OneWireBus * bus, bool *is_present);
-
-    /** NOTE: The data is shifted out of the low bits, eg. it is written in the order of lsb to msb */
+    owb_status (*reset)(const OneWireBus *bus, bool *is_present);
     owb_status (*write_bits)(const OneWireBus *bus, uint8_t out, int number_of_bits_to_write);
-
-    /** NOTE: Data is read into the high bits, eg. each bit read is shifted down before the next bit is read */
+    owb_status (*write_bytes)(const OneWireBus *bus, uint8_t *bytes, int number_of_bytes_to_write);     // new addition to the API
     owb_status (*read_bits)(const OneWireBus *bus, uint8_t *in, int number_of_bits_to_read);
+    owb_status (*read_bytes)(const OneWireBus *bus, uint64_t *in, int number_of_bytes_to_read);         // new addition to the API
 };
 
 /// @cond ignore
+// note: the new owb_rmt driver uses the ESP-IDF's built-in `__containerof()` macro instead of this
 #define container_of(ptr, type, member) ({                      \
         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
         (type *)( (char *)__mptr - offsetof(type,member) );})

include/owb_rmt.h

@@ -37,8 +37,11 @@
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/queue.h"
-#include "freertos/ringbuf.h"
-#include "driver/rmt.h"
+
+#include "driver/rmt_tx.h"
+#include "driver/rmt_rx.h"
+
+#include "owb.h"  // for tyoe OneWireBus
 
 #ifdef __cplusplus
 extern "C" {
@@ -49,25 +52,51 @@ extern "C" {
  */
 typedef struct
 {
-  int tx_channel;     ///< RMT channel to use for TX
-  int rx_channel;     ///< RMT channel to use for RX
-  RingbufHandle_t rb; ///< Ring buffer handle
-  int gpio;           ///< OneWireBus GPIO
-  OneWireBus bus;     ///< OneWireBus instance
+  rmt_channel_handle_t tx_channel_handle;     ///< RMT transmit channel, allocated by RMT driver
+  rmt_channel_handle_t rx_channel_handle;     ///< RMT receive channel, allocated by RMT driver
+  rmt_encoder_handle_t copy_encoder_handle;   ///< RMT built-in data encoder that sends pre-defined symbols
+  rmt_encoder_handle_t bytes_encoder_handle;  ///< RMT built-in data encoder that converts bits into symbols
+  rmt_symbol_word_t *rx_buffer;               ///< RMT receive channel symbol buffer
+  size_t rx_buffer_size_in_bytes;             ///< Size of the RMT received buffer, in bytes
+  QueueHandle_t rx_queue;                     ///< xQueue to receive RMT symbols from the `on_recv_done` callback
+  int gpio;                                   ///< OneWireBus GPIO
+OneWireBus bus;                               ///< OneWireBus instance (see owb.h)
 } owb_rmt_driver_info;
 
 /**
  * @brief Initialise the RMT driver.
  * @param[in] info Pointer to an uninitialized owb_rmt_driver_info structure.
  *                 Note: the structure must remain in scope for the lifetime of this component.
  * @param[in] gpio_num The GPIO number to use as the One Wire bus data line.
- * @param[in] tx_channel The RMT channel to use for transmitting data to bus devices.
- * @param[in] rx_channel the RMT channel to use for receiving data from bus devices.
+ * @param tx_channel NOW IGNORED: the new RMT driver allocates channels dynamically.
+ * @param rx_channel NOW IGNORED: the new RMT driver allocates channels dynamically.
  * @return OneWireBus *, pass this into the other OneWireBus public API functions
  */
 OneWireBus* owb_rmt_initialize(owb_rmt_driver_info * info, gpio_num_t gpio_num,
                                rmt_channel_t tx_channel, rmt_channel_t rx_channel);
 
+
+/**
+ * @brief Legacy RMT channel IDs.
+ * 
+ * These are no longer used for anything. They are defined here purely so
+ * that code written for the old rmt driver can still compile.
+ */
+typedef enum {
+    RMT_CHANNEL_0,  /*!< RMT channel number 0 */
+    RMT_CHANNEL_1,  /*!< RMT channel number 1 */
+    RMT_CHANNEL_2,  /*!< RMT channel number 2 */
+    RMT_CHANNEL_3,  /*!< RMT channel number 3 */
+#if SOC_RMT_CHANNELS_PER_GROUP > 4
+    RMT_CHANNEL_4,  /*!< RMT channel number 4 */
+    RMT_CHANNEL_5,  /*!< RMT channel number 5 */
+    RMT_CHANNEL_6,  /*!< RMT channel number 6 */
+    RMT_CHANNEL_7,  /*!< RMT channel number 7 */
+#endif
+    RMT_CHANNEL_MAX /*!< Number of RMT channels */
+} rmt_channel_t;
+
+
 #ifdef __cplusplus
 }
 #endif

include/owb_rmt_bus_symbols.h

@@ -0,0 +1,41 @@
+/**
+ * Copyright (c) 2023 mjcross
+ *
+ * SPDX-License-Identifier: MIT
+**/
+
+#include "owb_rmt_bus_timings.h"
+
+// RMT transmit channel symbols for the onewire bus signals and conditions
+//
+
+// basic bus levels
+// ----------------
+// note: we configure the transmit channel to be hardware inverted,
+//       so that the bus initialises in the 'released' state
+#define OWB_RMT_BUS_ASSERTED 1
+#define OWB_RMT_BUS_RELEASED 0
+
+// bus symbols as `rmt_symbol_word_t`
+// ----------------------------------
+
+// send 'zero' bit
+#define OWB_RMT_SYMBOL_0BIT { \
+    .level0 = OWB_RMT_BUS_ASSERTED, \
+    .duration0 = OWB_TIMING_PARAM_C, \
+    .level1 = OWB_RMT_BUS_RELEASED, \
+    .duration1 = OWB_TIMING_PARAM_D }
+
+// send 'one' bit
+#define OWB_RMT_SYMBOL_1BIT { \
+    .level0 = OWB_RMT_BUS_ASSERTED, \
+    .duration0 = OWB_TIMING_PARAM_A, \
+    .level1 = OWB_RMT_BUS_RELEASED, \
+    .duration1 = OWB_TIMING_PARAM_B }
+
+// send bus reset 
+#define OWB_RMT_SYMBOL_RESET { \
+    .level0 = OWB_RMT_BUS_ASSERTED, \
+    .duration0 = OWB_TIMING_PARAM_H, \
+    .level1 = OWB_RMT_BUS_RELEASED, \
+    .duration1 = OWB_TIMING_PARAM_I + OWB_TIMING_PARAM_J }

include/owb_rmt_bus_timings.h

@@ -0,0 +1,19 @@
+// onewire bus master timings
+
+// standard rate master timings recommended in the 1-Wire specification
+// the values below are the ones recommended by the specification.
+
+// for the meaning of each parameter, see the following document:
+// https://www.analog.com/en/technical-articles/1wire-communication-through-software.html
+
+// all values in microsec
+#define OWB_TIMING_PARAM_A  6 
+#define OWB_TIMING_PARAM_B  64
+#define OWB_TIMING_PARAM_C  60
+#define OWB_TIMING_PARAM_D  10
+#define OWB_TIMING_PARAM_E  9
+#define OWB_TIMING_PARAM_F  55
+#define OWB_TIMING_PARAM_G  0
+#define OWB_TIMING_PARAM_H  480
+#define OWB_TIMING_PARAM_I  70
+#define OWB_TIMING_PARAM_J  410