The Raspberry Pi outputs/accepts 3.3V levels signals and the printer outputs/accepts 5V signals. So by connecting the TX from the Raspi to RX from the printer the printer only sees there 3.3V signals. I’ve tested that with 2 different printers and both seem to accept and successfully detect the 3.3V signal (that has something to do with with TTL/CMOS logic level ranges/limits).
Please do not connect the TX from the printer to RX of the Raspberry Pi as you will feed 5V to the 3.3V Input Pin of the Pi which will most likely destroy the Pin or more when no level converter is used!
Each Friday is PiDay here at Adafruit, be sure to check out our posts, tutorials and new Raspberry Pi related products. Have you tried the new “Adafruit Raspberry Pi Educational Linux Distro” ? It’s our tweaked distribution for teaching electronics using the Raspberry Pi. But wait, there’s more! Try our new Raspberry Pi WebIDE! The easiest way to learn programming on a Raspberry Pi.
Want a FREE RASPBERRY PI? All orders over $350 get a FREE Raspberry Pi Model B with 512MB RAM!
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — Transforming Today’s Bad Jobs into Tomorrow’s Good Jobs
Wearables — Snap a picture
Electronics — To Y5V or not to Y5V?
Biohacking — Ticks are Spreading an Allergy to Meat
No comments yet.
Sorry, the comment form is closed at this time.