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Profile for uwezi

Nicely rendered 7-segment numbers

User cbm80amiga has uploaded a nice library to render 7-segment numbers on graphical displays – especially for Arduinos. But the code can as well be used without any Arduino in the proximity, just a slight change in the library made it an universal C++ object.

Here it runs on an ATmega328 and an OLED-display […]

Continue reading Nicely rendered 7-segment numbers

Temperature measurements with an NTC thermistor

sagecell.makeSagecell({“inputLocation”: “.sage”}); Following a discussion on Facebook I put here an online tool to calculate the output of a voltage divider consisting of a fixed resistor and an NTC thermistor following a first order Steinhart–Hart equation.

The calculations are based on a voltage divider where either the voltage over the NTC or over […]

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Not WormFood’s AVR Baud Rate Calculator

This page without a frame: https://sciencetronics.com/uwezi/avrbaudrate.php

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function resizeCallbackadvanced_iframe() {}function aiChangeUrl(loc) {}

Some Toner-Transfer PCB Highlights

Some recent highlights from my home-made circuit boards using the toner-transfer method.

0.5 mm FPC breakout board

Yes, I have been told that I am crazy before… Designed in KiCAD

0.5 mm pitch FPC breakout board – before etching

0.5 mm pitch FPC breakout board – half-way etched

Continue reading Some Toner-Transfer PCB Highlights

A tiny watchdog

In a recent quick-and-dirty project with a Wemos D1 mini clone I had some problems with the reliability of the code. The ESP8266 contains two watchdogs which have the sole purpose to reset the chip if the firmware ever should get stuck. Previously I experienced these watchdogs to be too aggressive, but this was […]

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Hacking IKEA trådfri lighting automation

I recently visited IKEA again and got interested in their affordable line of home automation/LED lighting products called TRÅDFRI (meaing wireless in a play-with-words kind of Swedish). Of course there was already an internet community active in hacking these devices and I joined in.

Getting started

I installed the gateway and after pairing devices […]

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project update: a TTL/CMOS computer

Exactly one month later – our electronics course at Uppsala University just approaches its end – and I got the next shipment for my new project: 1.1 km of equipment wire.

Top deal of the week?

Today I received a newsletter from the publisher Elektor. I am offered a special deal on a Peltier power generator which can power an LED light from a small candle. And this for an astonishing price of €99.95 instead of the normal price of €119.95.

Great offer from Elektor.

I’ll have to […]

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240×320 TFT with touch on an ATmega328

It’s been a while since I purchased some TFT modules on eBay. These modules come in different sizes and two varieties – with and without integrated touch controller XPT2046. The controller in the TFT display itself is an ILI9341 wired up to be controlled by SPI.

240×320 pixel TFT display with integrated […]

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Replacing three remotes

Idea

You know the problem – with every new gadget comes a new remote control, and while there are programmable and universal remote controls out there, they will never just do what you want.

The three main remotes in my living room.

For controlling my tv, my digital box and one of […]

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