4 files changed, 84 insertions, 2 deletions

diff --git a/src/modules/px4iofirmware/mixer.cpp b/src/modules/px4iofirmware/mixer.cpp
index a2193b526..e257e7cb8 100644
--- a/src/modules/px4iofirmware/mixer.cpp
+++ b/src/modules/px4iofirmware/mixer.cpp
@@ -59,6 +59,11 @@ extern "C" {
  */
 #define FMU_INPUT_DROP_LIMIT_US		200000
 
+/*
+ * Time that the ESCs need to initialize
+ */
+ #define ESC_INIT_TIME_US		500000
+
 /* XXX need to move the RC_CHANNEL_FUNCTION out of rc_channels.h and into systemlib */
 #define ROLL     0
 #define PITCH    1
@@ -69,6 +74,8 @@ extern "C" {
 /* current servo arm/disarm state */
 static bool mixer_servos_armed = false;
 
+static uint64_t time_armed;
+
 /* selected control values and count for mixing */
 enum mixer_source {
 	MIX_NONE,
@@ -176,8 +183,16 @@ mixer_tick(void)
 			/* save actuator values for FMU readback */
 			r_page_actuators[i] = FLOAT_TO_REG(outputs[i]);
 
-			/* scale to servo output */
-			r_page_servos[i] = (outputs[i] * 600.0f) + 1500;
+			/* scale to control range after init time */
+			if (mixer_servos_armed && (hrt_elapsed_time(&time_armed) > ESC_INIT_TIME_US)) {
+				r_page_servos[i] = (outputs[i]
+					* (r_page_servo_control_max[i] - r_page_servo_control_min[i])/2
+					+ (r_page_servo_control_max[i] + r_page_servo_control_min[i])/2);
+
+			/* but use init range from 900 to 2100 right after arming */
+			} else {
+				r_page_servos[i] = (outputs[i] * 600 + 1500);
+			}
 
 		}
 		for (unsigned i = mixed; i < IO_SERVO_COUNT; i++)
@@ -206,6 +221,7 @@ mixer_tick(void)
 		/* need to arm, but not armed */
 		up_pwm_servo_arm(true);
 		mixer_servos_armed = true;
+		time_armed = hrt_absolute_time();
 
 	} else if (!should_arm && mixer_servos_armed) {
 		/* armed but need to disarm */
diff --git a/src/modules/px4iofirmware/protocol.h b/src/modules/px4iofirmware/protocol.h
index 674f9dddd..1c9715451 100644
--- a/src/modules/px4iofirmware/protocol.h
+++ b/src/modules/px4iofirmware/protocol.h
@@ -183,6 +183,12 @@
 /* PWM failsafe values - zero disables the output */
 #define PX4IO_PAGE_FAILSAFE_PWM			105	/* 0..CONFIG_ACTUATOR_COUNT-1 */
 
+/* PWM minimum values for certain ESCs */
+#define PX4IO_PAGE_CONTROL_MIN_PWM		106	/* 0..CONFIG_ACTUATOR_COUNT-1 */
+
+ /* PWM maximum values for certain ESCs */
+#define PX4IO_PAGE_CONTROL_MAX_PWM		107	/* 0..CONFIG_ACTUATOR_COUNT-1 */
+
 /**
  * As-needed mixer data upload.
  *
diff --git a/src/modules/px4iofirmware/px4io.h b/src/modules/px4iofirmware/px4io.h
index 272cdb7bf..3e4027c9b 100644
--- a/src/modules/px4iofirmware/px4io.h
+++ b/src/modules/px4iofirmware/px4io.h
@@ -77,6 +77,8 @@ extern volatile uint16_t	r_page_setup[];		/* PX4IO_PAGE_SETUP */
 extern volatile uint16_t	r_page_controls[];	/* PX4IO_PAGE_CONTROLS */
 extern uint16_t			r_page_rc_input_config[]; /* PX4IO_PAGE_RC_INPUT_CONFIG */
 extern uint16_t			r_page_servo_failsafe[]; /* PX4IO_PAGE_FAILSAFE_PWM */
+extern uint16_t			r_page_servo_control_min[]; /* PX4IO_PAGE_CONTROL_MIN_PWM */
+extern uint16_t			r_page_servo_control_max[]; /* PX4IO_PAGE_CONTROL_MAX_PWM */
 
 /*
  * Register aliases.
diff --git a/src/modules/px4iofirmware/registers.c b/src/modules/px4iofirmware/registers.c
index df7d6dcd3..1fcfb2906 100644
--- a/src/modules/px4iofirmware/registers.c
+++ b/src/modules/px4iofirmware/registers.c
@@ -184,6 +184,22 @@ uint16_t		r_page_rc_input_config[MAX_CONTROL_CHANNELS * PX4IO_P_RC_CONFIG_STRIDE
  */
 uint16_t		r_page_servo_failsafe[IO_SERVO_COUNT] = { 0 };
 
+/**
+ * PAGE 106
+ *
+ * minimum PWM values when armed
+ *
+ */
+uint16_t		r_page_servo_control_min[IO_SERVO_COUNT] = { 900, 900, 900, 900, 900, 900, 900, 900 };
+
+/**
+ * PAGE 107
+ *
+ * maximum PWM values when armed
+ *
+ */
+uint16_t		r_page_servo_control_max[IO_SERVO_COUNT] = { 2100, 2100, 2100, 2100, 2100, 2100, 2100, 2100 };
+
 void
 registers_set(uint8_t page, uint8_t offset, const uint16_t *values, unsigned num_values)
 {
@@ -247,6 +263,42 @@ registers_set(uint8_t page, uint8_t offset, const uint16_t *values, unsigned num
 		}
 		break;
 
+	case PX4IO_PAGE_CONTROL_MIN_PWM:
+
+		/* copy channel data */
+		while ((offset < IO_SERVO_COUNT) && (num_values > 0)) {
+
+			if (*values > 1200)
+				r_page_servo_control_min[offset] = 1200;
+			else if (*values < 900)
+				r_page_servo_control_min[offset] = 900;
+			else
+				r_page_servo_control_min[offset] = *values;
+
+			offset++;
+			num_values--;
+			values++;
+		}
+		break;
+	
+	case PX4IO_PAGE_CONTROL_MAX_PWM:
+
+		/* copy channel data */
+		while ((offset < IO_SERVO_COUNT) && (num_values > 0)) {
+
+			if (*values > 1200)
+				r_page_servo_control_max[offset] = 1200;
+			else if (*values < 900)
+				r_page_servo_control_max[offset] = 900;
+			else
+				r_page_servo_control_max[offset] = *values;
+
+			offset++;
+			num_values--;
+			values++;
+		}
+		break;
+
 		/* handle text going to the mixer parser */
 	case PX4IO_PAGE_MIXERLOAD:
 		mixer_handle_text(values, num_values * sizeof(*values));
@@ -583,6 +635,12 @@ registers_get(uint8_t page, uint8_t offset, uint16_t **values, unsigned *num_val
 	case PX4IO_PAGE_FAILSAFE_PWM:
 		SELECT_PAGE(r_page_servo_failsafe);
 		break;
+	case PX4IO_PAGE_CONTROL_MIN_PWM:
+		SELECT_PAGE(r_page_servo_control_min);
+		break;
+	case PX4IO_PAGE_CONTROL_MAX_PWM:
+		SELECT_PAGE(r_page_servo_control_max);
+		break;
 
 	default:
 		return -1;