Schedule for Maker Faire

Usman and I will be demonstrating the Rail-O-Graph in the mornings at the Make: magazine booth. We’ll do a talk at 2pm on Saturday and 12:45 on Sunday on the project. On Sunday at 2pm, Mark Frauenfelder and I will talk about coffee hacks. We’ll have some fun stuff on hand, including Mark’s modified espresso machine, the Florence Siphon brewer I built, a new, miniature version of my hydraulic espresso tamper, and more. Can’t wait to see you there!



Rail-O-Graph early train tests

The Railographic Apparatus uses a train to deliver messages between terminal stations. My first tests were with HO scale trains. These were very helpful in testing the Arduino + Adafruit MotorShield, but proved to be a bit to small and unstable to lug around all the gear we wanted to use.

Rail-O-Graph build notes: tapping

Usman Muzaffar and I are working on a telecommunications project called The Rail-O-Graph. It’s a re-imagined Pony Express that passes messages between nodes using a microcontroller on a train. (Initial tests conducted with snakes on a plane did NOT go well.) I’m posting progress videos here as we race the clock to finish by Maker Faire. I previously posted a video of the simple switch > relay > solenoid > switch system here.

Here’s my exploration of solenoids and switches tapping at a constant rate:

The rate wasn’t so constant, until I put a protection diode across the solenoid leads. This was Tod Kurt‘s suggestion. Once again, Tod as saved me from putting the project into a little pile and setting it on fire.

First earbud owl Twitter winner announced!

The first winner of the Twitter contest has been randomly selected.

Congratulations to @barrymcw for being so, well, randomly selected!!

Would you like a chance to win an earbud owl cut on the Epilog Zing laser cutter? Of course you would! Each week in May another winner will be selected, so be sure to follow me, @johnedgarpark on Twitter.