[Sponsored by ARK] Bidirectional DShot

boards/ark/fmu-v6x/src/board_config.h

@@ -420,6 +420,9 @@
 /* This board provides a DMA pool and APIs */
 #define BOARD_DMA_ALLOC_POOL_SIZE 5120
 
+/* This board has 4 DMA channels available for bidirectional dshot */
+#define BOARD_DMA_NUM_DSHOT_CHANNELS 4
+
 /* This board provides the board_on_reset interface */
 
 #define BOARD_HAS_ON_RESET 1

boards/ark/fpv/src/board_config.h

@@ -307,6 +307,9 @@
 /* This board provides a DMA pool and APIs */
 #define BOARD_DMA_ALLOC_POOL_SIZE 5120
 
+/* This board has 3 DMA channels available for bidirectional dshot */
+#define BOARD_DMA_NUM_DSHOT_CHANNELS 3
+
 /* This board provides the board_on_reset interface */
 
 #define BOARD_HAS_ON_RESET 1

boards/ark/fpv/src/timer_config.cpp

@@ -58,7 +58,7 @@
 constexpr io_timers_t io_timers[MAX_IO_TIMERS] = {
 	initIOTimer(Timer::Timer5, DMA{DMA::Index1}),
 	initIOTimer(Timer::Timer8, DMA{DMA::Index1}),
-	initIOTimer(Timer::Timer4, DMA{DMA::Index1}),
+	initIOTimer(Timer::Timer4),
 };
 
 constexpr timer_io_channels_t timer_io_channels[MAX_TIMER_IO_CHANNELS] = {

boards/ark/pi6x/src/board_config.h

@@ -309,6 +309,9 @@
 /* This board provides a DMA pool and APIs */
 #define BOARD_DMA_ALLOC_POOL_SIZE 5120
 
+/* This board has 4 DMA channels available for bidirectional dshot */
+#define BOARD_DMA_NUM_DSHOT_CHANNELS 4
+
 /* This board provides the board_on_reset interface */
 
 #define BOARD_HAS_ON_RESET 1

platforms/nuttx/src/px4/nxp/imxrt/dshot/dshot.c

@@ -418,6 +418,21 @@ void up_bdshot_erpm(void)
 }
 
 
+int up_bdshot_num_erpm_ready(void)
+{
+	int num_ready = 0;
+
+	for (unsigned i = 0; i < DSHOT_TIMERS; ++i) {
+		// We only check that data has been received, rather than if it's valid.
+		// This ensures data is published even if one channel has bit errors.
+		if (bdshot_recv_mask & (1 << i)) {
+			++num_ready;
+		}
+	}
+
+	return num_ready;
+}
+
 
 int up_bdshot_get_erpm(uint8_t channel, int *erpm)
 {

platforms/nuttx/src/px4/rpi/rpi_common/include/px4_arch/io_timer.h

@@ -151,9 +151,6 @@ __EXPORT int io_timer_free_channel(unsigned channel);
 __EXPORT int io_timer_get_channel_mode(unsigned channel);
 __EXPORT int io_timer_get_mode_channels(io_timer_channel_mode_t mode);
 __EXPORT extern void io_timer_trigger(void);
-__EXPORT void io_timer_update_dma_req(uint8_t timer, bool enable);
-
-__EXPORT extern int io_timer_set_dshot_mode(uint8_t timer, unsigned dshot_pwm_rate, uint8_t dma_burst_length);
 
 /**
  * Returns the pin configuration for a specific channel, to be used as GPIO output.