From 155e82c1b309619b4c10092b3e3f78be6e567830 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Wed, 25 Nov 2015 18:10:30 +1100
Subject: [PATCH] HAL_PX4: fixed PWM output for FMUv4

---
 libraries/AP_HAL_PX4/RCOutput.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libraries/AP_HAL_PX4/RCOutput.cpp b/libraries/AP_HAL_PX4/RCOutput.cpp
index 06edc72e22..9a5be9b6e6 100644
--- a/libraries/AP_HAL_PX4/RCOutput.cpp
+++ b/libraries/AP_HAL_PX4/RCOutput.cpp
@@ -45,11 +45,13 @@ void PX4RCOutput::init(void* unused)
         _outputs[i].pwm_sub = orb_subscribe_multi(ORB_ID(actuator_outputs), i);
     }
 
+#if !defined(CONFIG_ARCH_BOARD_PX4FMU_V4)
     _alt_fd = open("/dev/px4fmu", O_RDWR);
     if (_alt_fd == -1) {
         hal.console->printf("RCOutput: failed to open /dev/px4fmu");
         return;
     }
+#endif
 
     // ensure not to write zeros to disabled channels
     _enabled_channels = 0;