From 6d0363faff7f5a59264198f04bae6f5b61c54510 Mon Sep 17 00:00:00 2001
From: px4dev <px4@purgatory.org>
Date: Sat, 26 Jan 2013 19:43:23 -0800
Subject: [PATCH] Disarm IO at driver startup time.

---
 apps/drivers/px4io/px4io.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/apps/drivers/px4io/px4io.cpp b/apps/drivers/px4io/px4io.cpp
index e48c84774e..f948fec2c4 100644
--- a/apps/drivers/px4io/px4io.cpp
+++ b/apps/drivers/px4io/px4io.cpp
@@ -308,6 +308,12 @@ PX4IO::init()
 	if (ret != OK)
 		return ret;
 
+	/*
+	 * Enable a couple of retries for operations to IO.
+	 *
+	 * Register read/write operations are intentionally idempotent
+	 * so this is safe as designed.
+	 */
 	_retries = 2;
 
 	/* get some parameters */
@@ -326,6 +332,12 @@ PX4IO::init()
 	if (_max_rc_input > RC_INPUT_MAX_CHANNELS)
 		_max_rc_input = RC_INPUT_MAX_CHANNELS;
 
+	/* dis-arm IO before touching anything */
+	io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 
+		PX4IO_P_SETUP_ARMING_ARM_OK |
+		PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE |
+		PX4IO_P_SETUP_ARMING_VECTOR_FLIGHT_OK, 0);
+
 	/* publish RC config to IO */
 	ret = io_set_rc_config();
 	if (ret != OK) {