From e246b8fcb38e4a574eb372868a069074b59b4c53 Mon Sep 17 00:00:00 2001
From: Michael Ingraham <34340210+meingraham@users.noreply.github.com>
Date: Wed, 12 Jun 2019 12:10:31 -0400
Subject: [PATCH] Update usable pins for ESP8255

---
 Expanding-Sonoffs.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Expanding-Sonoffs.md b/Expanding-Sonoffs.md
index dde8a501..665e6c4c 100644
--- a/Expanding-Sonoffs.md
+++ b/Expanding-Sonoffs.md
@@ -107,7 +107,7 @@ The [power supplied to the device](https://www.letscontrolit.com/wiki/index.php?
 
 ## Usable pins
 
-The ESP8266 has 17 GPIO pins (0-16), however, you can only use 11 of them, because 6 pins (GPIO 6 - 11) are used to connect the flash memory chip. This is the small 8-legged chip right next to the ESP8266. If you try to use one of these pins, you might crash your program.
+The ESP8266 and ESP8255 have 17 GPIO pins (0-16) but several are [reserved or have constraints](https://i.imgur.com/IH1fYqF.jpg). Do not use any of the _**reserved**_ pins. If you do, you might crash your program. On the ESP8266, six pins (GPIO 6 - 11) are used to interface the flash memory (the small 8-legged chip usually right next to the ESP8266). The ESP8255 has its flash memory integrated into the chip which frees up GPIO 9 and 10.
 
 GPIO 1 and 3 are used as TX and RX of the hardware Serial port (UART), so in most cases, you can’t use them as normal I/O while sending/receiving serial data.