[Solved] Connect RS232 thermal printer to the Core - 5V power?

Hi all, I would like to connect my old EPSON TM88-II RS232 printer to the Spark Core. The idea is to use a MAX3232-enabled connector for this, something like this.

Obviously, the MAX3232 requires 5 volts to operate.

Can I draw them from Spark pins when the Core is powered by USB? Can I power the MAX3232 with a different (5V) power source and it will work? Or is there any other way? Thank you very much.


Good news: I can confirm that the MAX3232 level shifter for serial communications work with both 3.3 and 5 Volts directly from the breadboard (powered by USB).

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Hi @akrusen,

I’m less familiar with the electrical stuff, so I hope someone will correct me if I misspeak. You can source 5V from the vin pin on the core when you’re powering the core via USB. But I don’t think the serial data lines themselves are 5v tolerant. Hopefully someone else can talk about the best way to connect that printer.

I hope that helps! :smile:


You could also use a MAX3232 to go from 3.3 to Serial comm

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Were you able to connect your old Epson TM88-II RS232 to the Spark Core?

Yes, I got it to work. Thank you!