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Raspberry Pi 3 Cookbook for Python Programmers - Third Edition
book

Raspberry Pi 3 Cookbook for Python Programmers - Third Edition

by Steven Lawrence Fernandes, Tim Cox
April 2018
Beginner content levelBeginner
552 pages
13h 58m
English
Packt Publishing
Content preview from Raspberry Pi 3 Cookbook for Python Programmers - Third Edition

The RS232 loopback

You can check whether the serial port connections are working correctly using a serial loopback.

A simple loopback consists of connecting RXD and TXD together. These are pins 8 and 10 on the Raspberry Pi GPIO header, or pins 2 and 3 on the standard RS232 D9 connector on the USB-RS232 adapter:

Serial loopback connections to test the Raspberry Pi GPIO (left) and RS232 9-Way D connector (right)

An RS232 full loopback cable also connects pin 4 (DTR) and pin 6 (DSR) as well as pin 7 (RTS) and pin 8 (CTS) on the RS232 adapter. However, this is not required for most situations, unless these signals are used. By default, no pins ...

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Publisher Resources

ISBN: 9781788629874Supplemental Content