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Showing posts from July, 2022

FlatCAM 8.994 Beta Tips

I'll be adding here some tips and how-tos on how on FlatCAM 8.994, an Open-Source PCB CAM tool. This is a work in progress and it's mostly for my own reference. I'll be updating it as I discover new stuff. Note that procedures shown may not be correct or the most efficient. This is provided "as is". FlatCAM's website:  http://flatcam.org/ Installation:  https://bitbucket.org/jpcgt/flatcam/downloads/ Create and save new project: Load Gerbers & Excellon: Single-sided isolation routing: On the left pane, double-click your front copper gerber, and you'll be taken to a Properties window. Choose Isolation routing. If the left pane somehow disappears, you may go to View > Toggle project/Properties/Tool. On tools & tools library: From within the isolation window, delete default tools and choose the tool you want to use, or create a new one. See the screenshow on how to do so. Here is how to configure a traditional V bit. To be continued... Soon (TM) Don

Water alarm

  Sometimes a water alarm may come in handy around the house, to notify you of leaks so you can do something about it before the mess grows beyond control. I designed and manufactured a rudimentary alarm that senses water through a simple conductive probe, and compains about it. It made for a perfect excuse to get back up to speed with KiCad and LTSpice, to recover from MicroSIM (1996 edition, ever heard of it? me neither) which they make us use at school. Beeing able to pan and zoom using the mouse is definitely something I've missed. Here is the schematic: A couple of transistors form an SCR-like circuit that latches on if water is detected. This powers a two transistor oscillator than in turn drives the buzzer. Almost zero power consumption on standby. Most values are non-critical, and timings are difficult to predict in this kind of circuits, as transistors have to be driven with certain base current to turn the buzzer on and this interferes with the time constants of the RC se