[geeks] Cheap TTL to RS-232 adapter

Lionel Peterson lionel4287 at gmail.com
Thu Nov 26 10:35:41 CST 2015


So I'm ordering a Raspberry Pi Zero from my local microcenter for $5, and my
goal is to put an emulation of a PDP/8 or similar system on it for fun... But
how to get terminal input/output? A microHDMI to (full size) HDMI adapter
costs 3x the price of the computer, and adding a USB keyboard would require a
hub increasing the cost/size/kludge factor, so what to do?

Add an RS-232 adapter, of course!

I searched on line, found out the Raspberry PI has header pins for a serial
port (at 3.3v TTL signal level), so a quick jaunt to eBay turned up this
adapter for $1.19 shipped from Hong Kong:

http://www.ebay.com/ulk/itm/252175537710

Title: TTL Converter Module MAX3232 DB9 Connector With Cable RS232 Port Serial

Now all I'll need to do is add header pins to the Raspberry Pi Zero and 'bob's
your uncle!'

Thought I'd share,

Lionel

PS - how the heck does one build a trivial circuit board, package it, and ship
it from Hong Kong to TX for $1.19?!


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