dennis.salzner
fau.de
In order to add wheel odometry I made additions hardware, electronics and software. For the hardware I needed to add a wheel encoder disk to the motor axles. This was 3D printed. As for the electronics, in order to pickup interruptions of that encoder disk, I needed to position a light barrier such that it doesn't jam the moving parts. For the software I had to get that PCF8583 I2C realtime clock chip to work as an impulse counter.
In order to accomodate for the Lidar, for which the SLAM algorithms in turn require wheel odometry data and the ESP32-CAM in order to provide a video stream, I had to rework much of the robot from 2018. I repositioned the electronics, swapped the main controller and rewired components to commincate via I2C making the robot more easily extensible.
For quite some time I've wanted to purchase a 360 lidar for one of my robots. They give the robot the ability to measure distances of obstacles surrounding it. 360 lidars are commonly used on robotic vacuums, but have been available for hobbyists for some time. I just couldn't justify the price for hobbyist projects. Recently the 'YouYeeToo' / 'WayPonDev' / 'LDRobot' 'FHL-LD20' or 'D200 Lidar Kit' came to by attention. It costs only 48 Eur. Let's see, if I can get it to work. If the signal is clean enough we can try Simultaneous Localization and Mapping.
Amateur radio and software defined radio is a big field with a lot to learn. It touches on various fields of technology from voice communication, but also digital transmission for WiFi, Smart Home and IoT. As such I've come into contact with it from various angles from time to time. The following summarizes what I've learned about receivers, antennas, connectors, cables, useful software and some signals I've received.
After just two days and, well, approx. 1500 shredded pages, my inexpensive Olympia PS 16 document shredder broke down. I've opened it up, found the issue and replaced the motor and broken gearbox with a cordless drill. It's a simple hack that will work on most of these shredders and save the machines from landfill. Along the way I've taken the opportunity to try out options for connecting motors to axles.
My Fujitsu fi-5110c auto-feed scanner broke down due to age-old feed rollers that have become sticky. The feed rollers had passed a threshhold of stickiness that prevent papers from passing through the feed mechanics.
A visit to the Signal Tower at the Nürnberg main train station. The Nürnberg train station, due to its location in Europe, is one of the most frequented train stations. It has three different generations of railroad signalling systems from relay-based electro-mechanical to fully digital. I've collected what I recall from memory with images found on various pages across the internet.
The initial setup of my solar power system is about 2 years ago. It’s an island system with a battery that does not feed into the grid and is completly off-grid capable.
CNC (=computerized numerical control) milling is the process of removing material by using a rotary cutter that is positioned by a computer. I have been constructing my own CNC milling machines and after many attemps with various levels of success, I switched to a commercial mechanics kit that I then modified for my purposes.
The DirtDevil Spider M607 is a cheap entry-level vacuum robot. It does not feature optical mapping, but rather randomly moves around until it hits an obstacle and then turns to avoid it. This works reasonably well, but I purchased the robot in order to modify it.
A small speaker and a small single board computer with some Linux software is all that is required to build a WiFi speaker. With it you will be able to listen to music within WiFi range and optionally control music with your smartphone.
The Atari ST Mega home computer was produced from 1985 to 1994. It uses the Motorola 68k line of chips as its main processor with a 16 bit data bus. The Atari ST Mega that I have came with an Atari Megafile hard disk and Atari SM124 monochrome monitor. In the following I describe the modifications I have made to make the computer useable in the 21st century.
PCB etching is the process of making your own circuit boards. There are multiple ways of achieving this. This is a description of my experiences and why I now avoid PCB etching, whenever possible.
The DigiStump DigiSpark is an excellent microcontroller development board. The price of only 1-2 Euro is so low you can drop it in your designs and leave it there. […] This Guide will show you how to setup the Arduino IDE, configure it for use with the DigiSpark Board, set up the drivers, connect it and compile and program the „Echo“ Example, which enables sending data to and from the DigiSpark via USB using either Python or C++.