Update README.rst

add cold solder joints hint
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Rotzbua
2017-12-03 11:30:31 +01:00
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parent 269625fe58
commit 19461b34d3

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@@ -221,6 +221,7 @@ Troubleshooting
* **I don't get input from reader** or **WARNING: Communication failure, is the MFRC522 properly connected?**
#. Check your connection, see `Pin Layout`_ .
#. Check your pin header soldering. Maybe you have cold solder joints.
#. Check voltage. Most breakouts work with 3.3V.
#. SPI only works with 3.3V, most breakouts seem 5V tollerant, but try a level shifter.
#. SPI does not like long connections. Try shorter connections.