Raspberry & thermal printer RX-TX with resistor?

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osoverflow
 
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Raspberry & thermal printer RX-TX with resistor?

Post by osoverflow »

Is it possible to connect the printer TX to the board RX pin (5v to 3.3v) using a resistor to let only the signal? Or I should use a zener diode to limit the voltage?

I was thinking of adding a 3.3 zener diode with the 10k resistor in series and take the output and connect to the raspberry to get 3.3 volts max and to be able to read the status of the printer...

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adafruit_support_rick
 
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Re: Raspberry & thermal printer RX-TX with resistor?

Post by adafruit_support_rick »

You could also use a pair of 10K resistors as a voltage divider. That's probably simpler.

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osoverflow
 
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Re: Raspberry & thermal printer RX-TX with resistor?

Post by osoverflow »

The two resistors in series, and the output between both?

Code: Select all

PRINTER ------R1(10k)-------|--------R2(10k)--------GND
                            |
                            |
                     INPUT in the Pi
Last edited by adafruit_support_mike on Wed Mar 19, 2014 2:29 pm, edited 2 times in total.
Reason: added CODE tags to preserve the formatting

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adafruit_support_mike
 
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Re: Raspberry & thermal printer RX-TX with resistor?

Post by adafruit_support_mike »

Yep, that should do it.

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