• The Ugly Sense

    06/27/2019 at 10:54 0 comments

    So you have made something. A drawing, a design, a device, a tool, a piece of clothes, a decoration. Whatever. And you see that it's not good. It's ugly, crooked, flimsy, brittle, and doesn't work well. Congratulations! You have the most precious and useful talent of all: the ability to tell when things are bad. With this talent it's only a matter of trying a lot of different approaches before you will be making masterpieces, because each time you will be able to tell if the thing you changed made it better of worse.

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  • Driving OLED Displays Directly

    12/18/2018 at 00:32 3 comments

    There are many monochrome OLED display modules available for really reasonable prices out there. They can be really useful for a small and simple display in a project. However, many libraries available for driving them are rather big and slow. In this article I want to show how easy it is to drive those displays directly, without a dedicated library, and how this can improve speed and save memory.

    As an example I will be using a Wemos D1 Mini (now Lolin D1 Mini) board with an OLED shield. To focus on the data we need to send, and not on details of environments and libraries, I will be using MicroPython for all of the code. I hope that once understood, the examples can easily be translated for any other board, display and language.

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  • Driving LED Matrices Conveniently

    11/04/2018 at 21:40 13 comments

    You can make a pretty neat low-resolution display out of LEDs arranged in rows and columns — you can even buy ready matrices that save you a lot of work with it. You "only" need one GPIO pin per every row and every column (you can save a lot of them by charlieplexing). The way you display things is that you enable one row (or column) at a time, and enable the columns (or rows) for that set of pixels, and then you disable it and switch to the next row (or column). If you do that quick enough, the LEDs won't even have time to stop shining, and you will have a pretty reasonable image displayed. But there are several problems with this.

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