Adjust the control mapping from DSM receivers to correspond to the standard PPM control mapping for channels 0-4.

1 files changed, 22 insertions, 4 deletions

diff --git a/apps/px4io/dsm.c b/apps/px4io/dsm.c
index 04aca709b..2611f3a03 100644
--- a/apps/px4io/dsm.c
+++ b/apps/px4io/dsm.c
@@ -322,10 +322,28 @@ dsm_decode(hrt_abstime frame_time)
 		/* convert 0-1024 / 0-2048 values to 1000-2000 ppm encoding in a very sloppy fashion */
 		if (channel_shift == 11)
 			value /= 2;
-
-		/* stuff the decoded channel into the PPM input buffer */
-		/* XXX check actual values */
-		system_state.rc_channel_data[channel] = 988 + value;
+		value += 998;
+
+		/* 
+		 * Store the decoded channel into the R/C input buffer, taking into
+		 * account the different ideas about channel assignement that we have.
+		 *
+		 * Specifically, the first four channels in rc_channel_data are roll, pitch, thrust, yaw,
+		 * but the first four channels from the DSM receiver are thrust, roll, pitch, yaw.
+		 */
+		switch (channel) {
+		case 0:
+			channel = 2;
+			break;
+		case 1:
+			channel = 0;
+			break;
+		case 2:
+			channel = 1;
+		default:
+			break;
+		}
+		system_state.rc_channel_data[channel] = value;
 	}
 
 	/* and note that we have received data from the R/C controller */