From d5388c5d311d1bc73b2dced8318b48db13780463 Mon Sep 17 00:00:00 2001
From: Flavien Haas <flavorita.hasso@gmail.com>
Date: Fri, 13 Apr 2018 10:02:39 +0200
Subject: [PATCH] Update README.md

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 README.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/README.md b/README.md
index e483f4a..d75f4f7 100644
--- a/README.md
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 # passerelleLoRa
 Projet BTS SNIR 2ème année
 Gateway between a weather MicroStation using LoRa modulation and a web server. This depo is segmented in different programs for arduino using ATMEGA328P and SAMD21.
+
+#Attention !
+Because we're using two arduino shields using SPI communication, we need to select a chip select for each shield. I decided to use D11 for the Ethernet shield (10 for the LoRa, 4 for the SD).
+
+To do this, edit w5100.h in the default ethernet librairy in the installation folder of your arduino IDE (on windows, in adminisstrator mode ‪C:\Program Files (x86)\Arduino\libraries\Ethernet\src\utility\w5100.h).