Merge pull request #6 from julianoes/ppm_encoder_fixes

ArduPPM

Two new defines added:

_THROTTLE_LOW_FAILSAFE_INDICATION: Throttle low indication and thus APM fail-safe triggering when a single channel error is detected.

_THROTTLE_LOW_RECOVERY_POSSIBLE: Throttle low is reset when a disconnected channel comes back and full control regained.

Tools/ArduPPM/ATMega328p/Encoder-PPM.c

@@ -1,5 +1,5 @@
 // ------------------------------------------------------------------------------------------------------------------------------------------------------------
-// ArduPPM Version v0.9.87
+// ArduPPM Version v0.9.89
 // ------------------------------------------------------------------------------------------------------------------------------------------------------------
 // ARDUCOPTER 2 : PPM ENCODER for AT Mega 328p and APM v1.4 Boards
 // By:John Arne Birkeland - 2011
@@ -35,11 +35,13 @@
 //	0.9.85 : Added brownout reset detection flag
 //	0.9.86 : Added a #define to disable Radio Passthrough mode (hardware failsafe for Arduplane)
 //	0.9.87 : #define correction for radio passthrough (was screwed up).
+//  0.9.88 : LED fail-safe indication is on whenever throttle is low
+//  0.9.89 : LED fail-safe change can be reverted with a define
 // ------------------------------------------------------------------------------------------------------------------------------------------------------------
 // PREPROCESSOR DIRECTIVES
 // ------------------------------------------------------------------------------------------------------------------------------------------------------------
 
-#include "..\Libraries\PPM_Encoder.h"
+#include "../Libraries/PPM_Encoder.h"
 #include <util/delay.h>
 
 
@@ -283,7 +285,11 @@ int main(void)
 	// ------------------------------------------------------------------------------
 	while( 1 )
 	{
+	#if defined _THROTTLE_LOW_RECOVERY_POSSIBLE
+		if ( throttle_failsafe_force )	// We have an error 
+	#else
 		if ( servo_error_condition || servo_input_missing )	// We have an error 
+	#endif
 		{
 			blink_led ( 6 * LOOP_TIMER_10MS ); // Status LED very fast blink if invalid servo input or missing signal
 		}
@@ -368,7 +374,11 @@ int main(void)
 		// ------------------------------------------------------------------------------
 		// Status LED control
 		// ------------------------------------------------------------------------------
+	#ifdef _THROTTLE_LOW_FAILSAFE_INDICATION
+		if ( throttle_failsafe_force ) // We have an error 
+	#else
 		if ( servo_error_condition || servo_input_missing )	// We have an error
+	#endif
 		{
 			blink_led ( 6 * LOOP_TIMER_10MS ); // Status LED very fast blink if invalid servo input or missing signal
 		}

Tools/ArduPPM/ATMega32U2/Projects/arduino-usbserial/Descriptors.c

@@ -54,7 +54,7 @@
  *  number of device configurations. The descriptor is read out by the USB host when the enumeration
  *  process begins.
  */
-USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
+const USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
 {
 	.Header                 = {.Size = sizeof(USB_Descriptor_Device_t), .Type = DTYPE_Device},
 		
@@ -91,7 +91,7 @@ USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
  *  and endpoints. The descriptor is read out by the USB host during the enumeration process when selecting
  *  a configuration so that the host may correctly communicate with the USB device.
  */
-USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
+const USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
 {
 	.Config = 
 		{
@@ -199,7 +199,7 @@ USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
  *  the string descriptor with index 0 (the first index). It is actually an array of 16-bit integers, which indicate
  *  via the language ID table available at USB.org what languages the device supports for its string descriptors.
  */
-USB_Descriptor_String_t PROGMEM LanguageString =
+const USB_Descriptor_String_t PROGMEM LanguageString =
 {
 	.Header                 = {.Size = USB_STRING_LEN(1), .Type = DTYPE_String},
 		
@@ -210,7 +210,7 @@ USB_Descriptor_String_t PROGMEM LanguageString =
  *  form, and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
  *  Descriptor.
  */
-USB_Descriptor_String_t PROGMEM ManufacturerString =
+const USB_Descriptor_String_t PROGMEM ManufacturerString =
 {
 	.Header                 = {.Size = USB_STRING_LEN(24), .Type = DTYPE_String},
 		
@@ -221,7 +221,7 @@ USB_Descriptor_String_t PROGMEM ManufacturerString =
  *  and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
  *  Descriptor.
  */
-USB_Descriptor_String_t PROGMEM ProductString =
+const USB_Descriptor_String_t PROGMEM ProductString =
 {
 	#if (ARDUINO_MODEL_PID == ARDUINO_UNO_PID)
 		.Header                 = {.Size = USB_STRING_LEN(11), .Type = DTYPE_String},

Tools/ArduPPM/Libraries/PPM_Encoder.h

@@ -1,5 +1,5 @@
 // -------------------------------------------------------------
-// ArduPPM (PPM Encoder) V2.3.13
+// ArduPPM (PPM Encoder) V2.3.14
 // -------------------------------------------------------------
 // Improved servo to ppm for ArduPilot MEGA v1.x (ATmega328p),
 // PhoneDrone and APM2.x (ATmega32u2)
@@ -127,6 +127,16 @@
 // V2.3.13 - Official release
 //         - Fail-safe vales changed back to normal fail-safe values. Use until APM code knows how to handle lost channel signal (800us)
 
+// 10-01-2013
+// V2.3.14pre - Internal test release
+//            - If one or more or all channel(s) are disconnected, throttle is set to fail-safe low (RTL)
+//            - If the misssing channel(s) are regained, throttle control is regained
+
+// 11-01-2013
+// V2.3.14 - temporary release for ArduCopter 2.9
+//         - fail-safe throttle low can be set with a define
+//         - recovery from error condition can also be set with a define
+
 // -------------------------------------------------------------
 
 #ifndef _PPM_ENCODER_H_
@@ -168,7 +178,7 @@
 #endif
 
 // Version stamp for firmware hex file ( decode hex file using <avr-objdump -s file.hex> and look for "ArduPPM" string )
-const char ver[15] = "ArduPPMv2.3.13"; 
+const char ver[15] = "ArduPPMv2.3.14"; 
 
 // -------------------------------------------------------------
 // INPUT MODE
@@ -189,6 +199,13 @@ volatile uint8_t servo_input_mode = JUMPER_SELECT_MODE;
 
 //#define _APM_FAILSAFE_   // Used to spesify APM 800us channel loss fail safe values, remove to use normal fail safe values (stand alone encoder board)
 
+//#define _THROTTLE_LOW_FAILSAFE_INDICATION //if set, throttle is set to low when a single channel is lost
+//#define _THROTTLE_LOW_RECOVERY_POSSIBLE //if set, throttle low recovers from being low when the single channel comes back, only makes sense together with _THROTTLE_LOW_FAILSAFE_INDICATION
+
+#if defined _THROTTLE_LOW_RECOVERY_POSSIBLE && !defined _THROTTLE_LOW_FAILSAFE_INDICATION
+#error failsafe recovery is only possible with throttle_low_failsafe_indication defined as well
+#endif
+
 // -------------------------------------------------------------
 // SERVO LIMIT VALUES
 // -------------------------------------------------------------
@@ -322,6 +339,11 @@ volatile uint8_t ppm_timeout[ PPM_ARRAY_MAX ];
 #define SERVO_INPUT_CONNECTED_VALUE 100
 volatile uint8_t servo_input_connected[ PPM_ARRAY_MAX ];
 
+#ifdef _THROTTLE_LOW_RECOVERY_POSSIBLE
+// count the channels which have been once connected but then got disconnected
+volatile uint8_t disconnected_channels;
+#endif
+
 // AVR parameters for PhoneDrone and APM2 boards using ATmega32u2
 #if defined (__AVR_ATmega16U2__) || defined (__AVR_ATmega32U2__)
 
@@ -413,6 +435,10 @@ volatile bool ppm_generator_active = false;
 // Used to indicate a brownout restart
 volatile bool brownout_reset = false;
 
+#ifdef _THROTTLE_LOW_FAILSAFE_INDICATION
+// Used to force throttle fail-safe mode (RTL)
+volatile bool throttle_failsafe_force = false;
+#endif
 
 // ------------------------------------------------------------------------------
 // PPM GENERATOR START - TOGGLE ON COMPARE INTERRUPT ENABLE
@@ -655,9 +681,21 @@ CHECK_PINS_LOOP: // Input servo pin check loop
                 servo_input_connected[ ppm_channel ]++;
             }
             
-           //Reset ppm single channel fail-safe timeout
+            //Reset ppm single channel fail-safe timeout
             ppm_timeout[ ppm_channel ] = 0;
 
+        #ifdef _THROTTLE_LOW_FAILSAFE_INDICATION
+            // Check for forced throttle fail-safe
+            if( throttle_failsafe_force )
+            {
+                if( ppm_channel == 5 )
+                {
+                    // Force throttle fail-safe
+                    servo_width = PPM_THROTTLE_FAILSAFE;
+                }
+            }
+        #endif
+    
         #ifdef _AVERAGE_FILTER_
             // Average filter to smooth input jitter
             servo_width += ppm[ ppm_channel ];
@@ -754,6 +792,16 @@ ISR( PPM_INT_VECTOR, ISR_NOBLOCK )
         PPM_COMPARE += failsafe_ppm[ ppm_out_channel ];
         sei();
 
+    #if defined _THROTTLE_LOW_RECOVERY_POSSIBLE && defined _THROTTLE_LOW_FAILSAFE_INDICATION
+        // Count the channel that we have lost
+        if( servo_input_connected[ ppm_out_channel ] )
+        {
+            disconnected_channels++;
+        }
+    #elif defined _THROTTLE_LOW_FAILSAFE_INDICATION
+        throttle_failsafe_force = true; 
+    #endif
+
     #if defined (__AVR_ATmega16U2__) || defined (__AVR_ATmega32U2__)
         // Turn on RX LED to indicate a fail-safe condition
         PORTD &= ~(1 << PD4);
@@ -777,6 +825,20 @@ ISR( PPM_INT_VECTOR, ISR_NOBLOCK )
     {
         ppm_out_channel = 0;
 
+	#ifdef _THROTTLE_LOW_RECOVERY_POSSIBLE
+        // Did we lose one or more active servo input channel? If so force throttle fail-safe (RTL)
+        if( disconnected_channels > 0 )
+        {
+            throttle_failsafe_force = true;
+        }
+        else
+        {
+            throttle_failsafe_force = false;
+        }
+
+        disconnected_channels = 0;
+    #endif
+
         #if defined (__AVR_ATmega16U2__) || defined (__AVR_ATmega32U2__)
         // Blink TX LED when PPM generator has finished a pulse train
         PIND |= ( 1<< PD5 );