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STC89C I/O Ports push-pull
The (English) datasheet contains Chapter 4, which explains how the I/O ports work as standard in the traditional 8051 way: so-called ‘quasi-bidirectional’. In this mode, when a ‘1’ is written to a port bit, the I/O floats high, with a weak pull-up resistor, and external devices are able to pull the pin low, so the […]
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12864B V2.0 LCD module
It’s 128×64 monochrome pixels, with a backlight, and can display graphics and ASCII text. It can also display Chinese, Japanese, Korean, characters using built-in fonts, but I didn’t investigate those facilities. Using the built-in ASCII font, the text resolution is fairly low – four rows with sixteen characters per row. The graphics can be switched […]
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SH-E 879 clock kit stopwatch
I first mentioned these kits about six years ago when I blogged about making this Arduino-based programmer for the AT89C2051 chip. The kits are still available on eBay, Banggood, AliExpress, … and there are plenty of variations that still use the AT89C2051 chip, but have more (three) push buttons, a buzzer, or only four digits […]
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Reading Arduino fuses using USBasp from Linux
Change to the directory where avrdude is located. If you don’t know, you can search for it with: sudo find / -name avrdude (find can take a long time to search the whole filesystem. You can interrupt it with Ctrl-c). For example, on my system (Linux Mint, May 2022) it was in a subdirectory of […]
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Arduino Due in Microchip Studio Part 1
Detailing my bumbling attempts to get everything working without the complexity of learning ASF. To follow this guide, you’ll need: A Due (obviously), Microchip Studio (formerly known as Atmel Studio, but it’s the same thing) which is free, and an Atmel-ICE Debugger and Programmer. The last item is expensive, but there are probably cheaper alternatives? […]
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Decoding FrSKY telemetry data with an Arduino – Part four
Now let’s look at the necessary code to transmit telemetry data from our aircraft. We have an Arduino on board the plane, connected to the telemetry port of our FrSky receiver. I used a D4R-II. The harness that plugs into the side of the receiver (at least the one supplied with mine) has red wire […]
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Decoding FrSKY telemetry data with an Arduino – Part three
So now we want to add our own types of data. We’ll still keep the standard FrSky telemetry data for all the standard sensors, but perhaps we want to send additional messages – these might be strings of characters, floating point values, integers, even possibly an image from a camera (though an image would take […]
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Solids of constant width – the Meissner Tetrahedron – in OpenSCAD
Lots of people know about curves of constant width – for example the UK 50p and 20p coins: despite their apparent non-roundness they have constant width when measured by parallel jawed calipers or the mechanisms inside vending machines.? If the shapes of these coins are extruded as prisms they can be used as rollers for […]
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E-paper display module driven by Arduino
These E-paper displays work well and look nice.? At the time of writing you can get the 1.54 – inch size (200 x 200 pixels) from Banggood, but there are other sizes in the same range and my code should work with the bigger ones too.? I have one on order to test.? Search on […]
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Revisiting the MinAttak chess problem
I blogged about my old Java Applet for the chess minimum attack (dominance) puzzle previously here. But of course Java Applets are now deader than a very dead thing that’s also been poisoned, burnt, and crushed.? I’ve been playing around trying to learn a bit more JavaScript, and as a learning exercise, I coded up […]