diff --git a/content/ardupilot/miscellaneous-notes.md b/content/ardupilot/miscellaneous-notes.md
index 4f183b5..82e1a65 100644
--- a/content/ardupilot/miscellaneous-notes.md
+++ b/content/ardupilot/miscellaneous-notes.md
@@ -19,9 +19,15 @@ If you got some DJI goggles, here's the relevant configuration you need to make:
 
 That's it!
 
+## DMA on the Matek F405-Wing
+
+If you want to get DMA on UART3 of the Matek F405-Wing FC (or, more relatedly, the Racerstar F405, because UART1 is Bluetooth there), you can open `libraries/AP_HAL_ChibiOS/hwdef/MatekF405-Wing/hwdef.dat` and comment out line 92ish, where PA15 is defined.
+
+That will enable DMA on UART3, at the expense of disabling the LED pad.
+
 * * *
 
 <p style="font-size:80%; font-style: italic">
-Last updated on October 19, 2021. For any questions/feedback,
+Last updated on October 20, 2021. For any questions/feedback,
 email me at <a href="mailto:hi@stavros.io">hi@stavros.io</a>.
 </p>