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Showing posts from April, 2022

Zmodem File Transfer With GNU Screen

I've been using screen as my serial terminal (as opposed to minicom or picocom) for a long time now.  Today I had the need to transfer a file from my PC to the embedded device I was connected to with screen.  Networking was not working, and a co-worker reminded me that zmodem was a way to transfer a file over the serial port.  I googled for instructions on exactly how to use zmodem and I found stack overflow answers and blog entries all mentioning GNU screen for doing so, but none of them really explained it right.  Here's what worked for me today. To transfer a file from my PC to the embedded device: in screen hit ctrl-a : zmodem catch in screen, at the linux command-line on your device type: rz screen will prompt with an sz command, just append the filename to that command and hit enter Note that this works best if the file is in the same directory as you ran screen from.   To send a file from the embedded device to your PC: in screen hit ctrl-a : zmodem catch in screen, at

Giving Bitcoin as a Gift

 If you've been following along, you know I was considering giving bitcoin as a Christmas gift .  I did end up giving bitcoin to friends and family for Christmas.  I'm pretty happy with how it turned out.  I went with the HD Paper Wallet solution, and so I wrote some python code to generate paper wallets .  The code is open source, and instructions are in the README there on github.  You'll probably want to tweak the template to customize it for you instead of me.  Hopefully someday I can modify the code to make that easy, but I'm pretty new at generating images and PDFs.  The code I write for my day job doesn't involve pretty pictures, or words even :-)