From 69680b04e9f98f54c826cd8f77e01973343e6183 Mon Sep 17 00:00:00 2001 From: Patrick Kanzler Date: Wed, 6 Jan 2016 12:13:35 +0100 Subject: [PATCH] DOC added notice on RS232 voltage levels fixes #41 --- doc/user/raspi.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/doc/user/raspi.rst b/doc/user/raspi.rst index 8786768..387c648 100644 --- a/doc/user/raspi.rst +++ b/doc/user/raspi.rst @@ -7,6 +7,11 @@ This instructions were tested on Raspbian. Unless you have done any distro with libusb-1.0 on the Raspberry Pi, the following instructions should works fine on your raspberry distro. +.. warning:: You should **never** directly connect an printer with RS232-interface (serial port) directly to + a Raspberry PI or similar interface (e.g. those simple USB-sticks without encasing). Those interfaces are + based on 5V- or 3,3V-logic (the latter in the case of Raspberry PI). Classical RS232 uses 12V-logic and would + **thus destroy your interface**. Connect both systems with an appropriate *level shifter*. + Dependencies ------------