Bits & Pieces

Digital Filters

The Basics about Digital Filters like IIR and FIR. How to simulate and design them with SciLab and run them on ARM MCUs using the CMSIS-DSP library. Also some benchmarks results for different MCUs and settings.

Helmholtz Coil

The basics about Helmholtz coils: Basic physics, applications and formulas. Interactive online calculator to aid in designing a simple two coil Helmholtz cage.

HDLC/AX.25

The basics about HDLC and AX.25 frames, how they are composed and assembled. Interactive online AX.25/HDLC frame generator (encoder and decoder).

AX5043

A very versatile and configurable Sub-GHz transceiver. Operates from 27 MHz to 1050 MHz. Offers multitude of different modulations like (G)FSK, (G)MSK, AFSK, PSK, ASK and FM, with datarate up to 125 kbps.

AFSK

An explanation on what is AFSK, how it works and for what it is used. Showcase of a digital implementation using Scilab of both modulation and demodulation. This includes FM modulation/demodulation, Audio-FSK modulation/demodulation and emphasis filter.