Electronics on bytebang

Fish-o-mat: An Aquaponics Greenhouse Controlled by ESPHome and Home Assistant

Wed, 28 Oct 2026 00:00:00 +0000

The Problem

Aquaponics combines fish farming and plant cultivation in one water cycle: the fish produce nutrients, bacteria convert them, and the plants clean the water that flows back to the fish. In my greenhouse two separate systems – a left and a right side – are running, each with its own fish tank, grow bed and vertical pipe towers for lettuce. The fish are catfish.

Such a system only works if a handful of things run reliably, day and night, all year round:

IoT parking sensor - LoRaWAN version

Mon, 29 Jul 2019 17:57:02 +0200

The Problem

The parking sensor which was built in part one of this series was able to connect to a WiFi and transmit the data via MQTT with the software shown in part two of this series.

This is a very good approach if you want to test something in an early prototyping phase. If you want to roll out your devices then it is very unlikely that you will have a WiFi deployed wherever you sensor will be. So you have to look for another transmission technology for the last mile.

IoT parking sensor - MQTT version

Mon, 24 Jun 2019 16:45:35 +0200

The Problem

In part 1 of this series we have covered the schematics and hardware for a IoT parking sensor. Now we are gonna have a look into the software which is able to transmit the state of the device to an arbitrary MQTT broker.

The Solution

The software is straight forward:

Set up the display
Connect to the WiFi
Connect to the MQTT broker
Read and transmit the sensor reading continuously

Here is my implementation:

Howto build your own IoT parking sensor

Wed, 22 May 2019 16:45:16 +0200

The Problem

Recently I had to build a prototype for a parking sensor application. The goal was to detect if a parking place is occupied or not.

Since there are multiple approaches to this, I decided to build a cheap module which can be mounted inside a garage (or any other dry place) and which can be powered either by a plain USB charger or by a 9V-Block.

The Solution

For the hardware I decided to go with my TTGOv2 board and LuaRTOS as operating system on it. It has a small display and it enables me to send the data either via MQTT or via LoraWan.

Porting LUARTOS to the TTGO LORA v2.0 Board

Fri, 29 Mar 2019 07:52:39 +0100

The Problem

I ordered for a parking sensor project some TTGO v2 Boards. Since I am a big fan of the LuaRTOS project i had to port it to this Hardware architecture.

The schematic:

For all of you who do not want to build your own firmware: Here is a precompiled version with all the features from below. Just extract it to a folder and flash it with the esptool.py

Porting LuaRTOS to the TTGO LoRa32 Board

Sun, 14 Oct 2018 18:34:27 +0200

The Problem

I have bought two cheap ESP32 based IoT development boards for around 30$, because the specs looked interesting:

ESP32 based with 3D- wifi antenna
128x64 pixel OLED display
LoRa Modem

This hardware has the potential to be a very versatile IoT prototyping (and even production) platform, but there was one drawback: You have to program it in the Arduino IDE. This means: You can do almost anything with it, but whenever you want to change something in the software then you have to recompile and upload everything.

Engrave things with a 3.5W Eleksmaker and LaserWeb

Tue, 01 May 2018 18:48:44 +0200

The Problem

In summer 2015 I ordered the predecessor of this 3.5W laser diode with TTL modulation. My initial plan was to mount it onto my 3d printer - but we all know: plans are patient.

Lately I stumbled upon this diode in my junk box. I decided to finish the project and I ordered an Eleksmaker A3 frame (without Laser). It is big enough to engrave / cut things with a size of 300 x 400 mm.

Add display fonts to custom built NodeMCU firmwares

Sun, 01 Apr 2018 14:23:02 +0200

The Problem

In my previous article I showed how to compile a custom firmware for the WeMos Lolin board and how to get the display up and running.

Since then I have played around with it and i wondered how to switch between different fonts for this display and where these magic constants within the LUA code are coming from.

The Solution

I figured out that fonts have to be ’enabled’ within the firmware. It ts quiet simple to do this:

Compile NodeMCU for WeMos Lolin ESP32 with OLED

Mon, 19 Mar 2018 12:46:58 +0100

The Problem

Recently I bought a Wemos Lolin ESP32 module. This prototyping board consists of a powerful ESP32 processor and a small OLED display which are mounted on a breadboard friendly PCB board.

Unfortunately, the reseller shows only examples how to program the controller and the display which are working in the Arduino IDE. This means that if you change your program, then you will have to recompile the whole code.

Flash a hex file into an Arduino without IDE

Sun, 25 Feb 2018 11:01:27 +0100

The Problem

I wanted to update my laser cutter. Therefore i choose to use the newest version of GRBL (version 1.1f) into the controller. Since I did not want to recompile the whole thing from scratch, I decided to download the lates version and just flash it into a new Arduino nano clone.

The big question was: How to do it ?

The Solution

The simplest solution was to download the hex file to my desktop and to utilize avrdude (which is also used from within the arduino ide to upload compiled code to the controller).

Automotive 2-channel PWM dimmer

Sat, 07 Nov 2015 12:57:39 +0100

The Problem

A colleague who is restoring an old-timer bus asked me if I know where to get an electronic circuit that is able to dim two different lights - but with just one knob. The reason behind this is that the old-timer bus has only one mounting hole left in its dashboard. He reported that they tried to build such a circuit wit a potentiometer (out of an old radio), but without success. So it became my task to design such a circuit.

IPTV with a Synology DS713+

Mon, 19 Oct 2015 16:31:01 +0200

The Problem

Recently i purchased an Amazon FireTv Stick - which is a great device for video streaming. But I wanted more than this stick offers out-of-the-box: I wanted to be able to stream DVB-T and DVB-S (digital terrestrial and digital satellite) signals through my IP network. Somewhere in the internet I stumbled across a few articles which components are needed for this purpose, but in the end I had no idea if and how it would work. I wanted the setup to look like this:

Aviation Headset to USB Adapter

Sun, 14 Dec 2014 10:14:01 +0100

The problem

As a part time motor pilot in our aviation club ASFC Leoben I decided on a hot summer day where i had to wear the sweat soaked one-for-all headset in our DR48 to buy my own headset. It had to be one with active noise reduction that is comfortable to wear and it had to have a bluetooth interface for accepting calls during long flights. After reading some reviews and after trying some of them I went with the BOSE A20 Aviation headset. Even after hours of wearing this headphones i did not have headache or any other complaints and so the choice was perfectly right.

Portable HAM radio station

Tue, 09 Dec 2014 20:16:27 +0100

My way to HAM radio

Since the age of 15 i wanted to to be a licensed HAM radio operator because radio fascinated me all the time. Unfortunately the motivation to do the exam to get the needed license was moderate because I thought had to visit a boring course and I had to learn Morse (CW) code to pass the exam. One day I stumbled across the OEVSV homepage page (= austrians ham radio association) and discovered that there was neither the need to learn cw code nor the need to visit a course to be approved to the A-class examination any more. Well at this point in time I ran out of arguments against myself and I decided to do this exam.

Quick and dirty high-resolution webcam

Mon, 01 Sep 2014 18:36:28 +0200

Recently i had the idea to build a(nother) webcam for my club to enable the gliderpilots to observe the weather in the alps. It should be cheap, easy to build and it should have a high resolution - A perfect field of application for my underemployed raspberry pi and its camera module. Both can be orderet at RS-Components for under 50 € (excluding a housing and a power supply).

The first step was to enable the camer module on the pi, which is rather simple: Open the raspi-config tool from the Terminal

ASCII - Art youtube player

Thu, 28 Aug 2014 19:48:43 +0200

I was sitting in front of my raspberry pi and asked myself: “What if X Servers, Windowmanagers and all the other graphical stuff would heve never been invented ? .. How would pepole watch youtube videos.”. Beside the fact that the possibility of having youtube in this very special case is really small, this type of question reveals that it was not one of my brightest moments … but it lead me to a really cool attempt how to watch videos in ascii art.

Bluelog - the fast bluetooth scanner

Mon, 18 Aug 2014 20:07:34 +0200

Bluelog is a wonderful piece of software - it is able to detect all bluetooth devices (that are in the discoverable state) very quickly and without the need of an interface. In opposite to OpwnWRT or some other Linux distributions it is not installable via the package manager in Ubuntu 14.04, but it can easily be compiled by yourself.

Installation on Unubtu 14.04

Well - this time you have to get your hands dirty. Make sure that you have installed the following packages: git, build-essentials (available in the main repository) and libbluetooth-dev.

X Forwarding with the Rasperry Pi

Mon, 18 Aug 2014 08:18:17 +0200

You can use the installed applications on your Rasperry Pi without the need of installing a VNC server or another Remote Desktop tool. Everything is already there - right out of the box.

The name of the game: X-Screen forwarding

Prequisites

Installed Raspiban
Enabled SSH Server on the Raspberry
A SSH Client that is able to display a forwarded X-Window.

Howto

The first step is to conenct to your rasperry via SSH. The important option is the ‘-X’. This requests X forwarding to the client (which is enabled by default at the raspiban ssh server).