Design Patterns for accessing hardware Probably the most distinguishing property of embedded systems is that they must access hardware directly. The whole point of an embedded system is that the software is embedded in a “smart device” that provides some specific kind of service, and that requires accessing hardware. Broadly,…
Programação em baixo nível em C – acesso ao hardware
Design Patterns no acesso ao hardware A característica mais marcante dos sistemas embarcados é que eles precisam acessar o hardware diretamente., uma vez que o objetivo de um sistema embarcado é que o software esteja incorporado em um “dispositivo inteligente” que forneça algum tipo específico de aplicacao, e isso exige…
GPIOs in ATMega328P – Arduino Uno and Nano
Ports as general digital I/O Sometimes it is a bit difficult to understand the meaning of the most common terms we come across when reading documentation about microcontrollers. When reading about the general purpose input-output module, the terms port and pin often clash with our intuition of what these terms…
AND Gate built with two diodes
1- Introduction Following the same idea on simulating some digital gates on LTSpice and reproducing them on the bench, here I simulate an AND gate in LTSpice and assemble a simple circuit on the bench. By comparing these two approaches I intend to facilitate understanding on the gate’s functionality, so…
The OR gate made with two discrete diodes
The OR gate As an exercise to practice some topics on analogue electronics at the bench, I developed an OR gate using two 1N4004 diodes. The bibliography I used was the classic “Electronic Devices and Circuit Theory” from Boylestad, in its chapter on diodes. I also modelled the circuit in…
The humidity sensor
Summary This document completely describes the humidity sensor: the motivation for creating it, its technical specifications and how it is being currently used. Background After spending time at home during the first 2020 lockdown in the UK (between March and August 2020), I developed the hobby of taking care of…