diff --git a/content/ardupilot/_index.md b/content/ardupilot/_index.md
index ba7a03b..ae10e8b 100644
--- a/content/ardupilot/_index.md
+++ b/content/ardupilot/_index.md
@@ -10,6 +10,7 @@ Click on a link in the list below to go to that page:
 
 1. [ArduPilot setup checklist](../../ardupilot/ardupilot-setup-checklist)
 1. [Building ArduPilot](../../ardupilot/building-ardupilot)
+1. [Configuring a switch as a relay](../../ardupilot/configuring-a-switch-as-a-relay)
 1. [Reverse thrust](../../ardupilot/reverse-thrust)
 1. [TECS tuning calculator](../../ardupilot/tecs-tuning-calculator)
 1. [Transfer config between craft](../../ardupilot/transfer-config-between-craft)
diff --git a/content/ardupilot/configuring-a-switch-as-a-relay.md b/content/ardupilot/configuring-a-switch-as-a-relay.md
new file mode 100644
index 0000000..939bc51
--- /dev/null
+++ b/content/ardupilot/configuring-a-switch-as-a-relay.md
@@ -0,0 +1,23 @@
++++
+title = "Configuring a switch as a relay"
+weight = 3
+sort_by = "weight"
+insert_anchor_links = "right"
++++
+If you want to connect a relay of some sort (something that accepts a low/high signal) to a PWM output (the servo outputs), you need to do a few quick things. The actual numbers will vary depending on your FC, but here's what worked for me with a Matek F405-Wing:
+
+1. Set the channel you want the relay to trigger on as a controller for the first relay (here I'll assume you want to control the first relay on channel 11):  
+  `RC11_OPTION=28`
+2. Set the pin number for the relay you want to control. This is a bit fuzzy, it depends on your flight controller, but try a few out. This is what worked for me, for S6 on my F405-Wing:  
+  `RELAY_PIN=55`
+3. Set a servo to act as a GPIO output. I'm assuming here you want `SERVO6`, though I'm not quite sure how the servo selection maps to the `RELAY_PIN` selection above. For me, `AUXOUT6` and `SERVO6` worked:  
+  `SERVO6_FUNCTION=-1`
+
+If you're amazingly lucky, you should be all set. If not, you need to play with the `50` in the `RELAY_PIN` parameter and the `6` in the `SERVO6_FUNCTION` until something works.
+
+* * *
+
+<p style="font-size:80%; font-style: italic">
+Last updated on September 11, 2021. For any questions/feedback,
+email me at <a href="mailto:hi@stavros.io">hi@stavros.io</a>.
+</p>
diff --git a/content/ardupilot/reverse-thrust.md b/content/ardupilot/reverse-thrust.md
index d097f25..42eeeb1 100644
--- a/content/ardupilot/reverse-thrust.md
+++ b/content/ardupilot/reverse-thrust.md
@@ -1,6 +1,6 @@
 +++
 title = "Reverse thrust"
-weight = 3
+weight = 4
 sort_by = "weight"
 insert_anchor_links = "right"
 +++
diff --git a/content/ardupilot/tecs-tuning-calculator.md b/content/ardupilot/tecs-tuning-calculator.md
index ff451b6..b406f3d 100644
--- a/content/ardupilot/tecs-tuning-calculator.md
+++ b/content/ardupilot/tecs-tuning-calculator.md
@@ -1,6 +1,6 @@
 +++
 title = "TECS tuning calculator"
-weight = 4
+weight = 5
 sort_by = "weight"
 insert_anchor_links = "right"
 +++
diff --git a/content/ardupilot/transfer-config-between-craft.md b/content/ardupilot/transfer-config-between-craft.md
index eda1190..bf52d16 100644
--- a/content/ardupilot/transfer-config-between-craft.md
+++ b/content/ardupilot/transfer-config-between-craft.md
@@ -1,6 +1,6 @@
 +++
 title = "Transfer config between craft"
-weight = 5
+weight = 6
 sort_by = "weight"
 insert_anchor_links = "right"
 +++
diff --git a/content/ardupilot/tuning-the-tecs.md b/content/ardupilot/tuning-the-tecs.md
index 4391a31..671b1a6 100644
--- a/content/ardupilot/tuning-the-tecs.md
+++ b/content/ardupilot/tuning-the-tecs.md
@@ -1,6 +1,6 @@
 +++
 title = "Tuning the TECS"
-weight = 6
+weight = 7
 sort_by = "weight"
 insert_anchor_links = "right"
 +++