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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

.errordiv { padding:10px; margin:10px; border: 1px solid #555555;color: #000000;background-color: #f8f8f8; width:500px; }#advanced_iframe {visibility:visible;opacity:1;vertical-align:top;}.ai-info-bottom-iframe { position: fixed; z-index: 10000; bottom:0; left: 0; margin: 0px; text-align: center; width: 100%; background-color: #ff9999; padding-left: 5px;padding-bottom: 5px; border-top: 1px solid #aaa }#ai-layer-div-advanced_iframe p {height:100%;margin:0;padding:0} var ai_iframe_width_advanced_iframe = 0; var ai_iframe_height_advanced_iframe = 0;var aiIsIe8=false;var aiOnloadScrollTop=”true”; if (typeof aiReadyCallbacks === ‘undefined’) {
var aiReadyCallbacks = [];
} else if (!(aiReadyCallbacks instanceof Array)) {
var aiReadyCallbacks = [];
} function aiShowIframeId(id_iframe) { jQuery(“#”+id_iframe).css(“visibility”, “visible”); } function aiResizeIframeHeight(height) { aiResizeIframeHeight(height,advanced_iframe); } function aiResizeIframeHeightId(height,width,id) {aiResizeIframeHeightById(id,height);}var ifrm_advanced_iframe = document.getElementById(“advanced_iframe”);var hiddenTabsDoneadvanced_iframe = false;
function resizeCallbackadvanced_iframe() {}function aiChangeUrl(loc) {}

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 […]

Continue reading A tiny watchdog

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 […]

Continue reading 240×320 TFT with touch on an ATmega328

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 […]

Continue reading Replacing three remotes

Hacking an AVR programmer II

This is a follow-up of my most popular post, Hacking an AVR programmer.

MX USBasp v3.02

Recently there have been quite a few comments about a new version 3.02 layout of the USBasp programmer available from many Chinese ebay sellers, which appears to be incompatible with my previous hack. The problem is still that […]

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Assembling an USBasp

…at eight times timelapse it only takes 4 ½ minutes…

http://www.sciencetronics.com/greenphotons/wp-content/uploads/2016/11/20161102_usbasp_480.webm

An USBasp in a new design II

Most of the time I design and debug my AVR projects on solderless breadboards nowadays. And for that I have been using some different types of programmers by now: starting with the good old STK500, to different versions of USBasp clones from Chinese sellers on eBay.

In order to connect the programmers to the […]

Continue reading An USBasp in a new design II

An USBasp in a new design

Just a small teaser: today I received my circuit boards from PCBgogo – a layout which I just had sent to the Chinese manufacturer last Sunday.

The finished circuit board from China.

It is a USBasp, which can be placed on a breadboard and at the same time supplies the power rails […]

Continue reading An USBasp in a new design