Sunroom Logger Part 5

Data Structures I spent some time with MySQL Workbench setting up a data structure that should allow an unlimited number of sensors to be logged to a generic structure. This database structure was deployed to a local server on my windows development machine, the Pi (running MariaDB, which appears to work with MySQL Workbench with only minor complaints), and also to my webhost. This is similar to a structure I use at work. Each ‘device’ can then have a local DB that is always available. Then some (so far unwritten) task can copy the data up to the webhost, which is used as a warehouse for the data. If for some reason the pi loses its network connection, it still can record locally with no data loss. There is a stored procedure on the DB that the program can use to determine what kind of device it is (not hard […]

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Extruder fan controller

I brought my makerbot to the Reading Friends and Family Day to show at the Reading Robockets booth. I’ve been having some issues with the extruder skipping, and I think part of the problem is that the stepper motor that does the extrusion is overheating a little. MIT Swapfest was also this past weekend, and I got a number of small useful items, like a few of these fans for $1 each (including the finger guard). these fans are LOUD and move a lot of air.   One thing that I liked about the fans is that they are the four wire variety which means they can have speed controlled with a PWM signal applied to the blue wire. The base frequency is around 25 kHz, and the duty cycle controls speed (from 30% to 100%). I did a bit of research online, and came across a neat ieda for […]

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