From Microcontroller to Mainframe

In the past 20 years I worked on systems as small as 8bit microcontrollers with no Operating System to systems as large as IBM Z-Series Mainframes. I wrote software for small FreeRTOS, Zephyr and RTEMS based controllers with only a few LED’s as “output” to GUI programs for Windows and Linux.

Since low level programming has some special demands on the programming language the main languages I use, and consider myself a professional in, are C, C++, and when it can’t be avoided assembly. Other languages like Python, bash-scripting, lua, cmake, are also part of my daily work.

Due to personal interest and experience there are some areas where I can offer additional knowledge that can speedup things compared to software developers that are new in those areas.

Linux Embedded Distribution Development

For systems that can’t use an average Linux distribution like Debian, Fedora, etc. because of for example storage size restrains I develop highly customizable distributions based on PtxDist or Yocto that can be as small as 8 MByte.

Low Level Driver Development

When there is a need for a small specialized Linux distribution it most of the times means there is some custom hardware in use. For that hardware I can develop low level device drivers for the Linux kernel and bootloaders like U-Boot and Barebox.

RTOS and Baremetal

For systems where a 8 MByte OS is still to large I can offer baremetal or RTEMS, FreeRTOS and Zephyr based solutions on PowerPC, AVR32, and mostly ARM.

Lighting Control

Lighting Control for stage and theater is an rather specialized area with several unique technologies. Having knowledge of technologies like for example DMX, RDM, Art-Net and ACN, makes it a lot easier for me to get up to speed in software development projects that deal with those technologies.

Public Information Systems

Like with Lighting Control systems, Public Information Systems in the public transportation area deal with specialized protocols and demands. Working for clients in doing public transportation information systems and for clients doing public transportation power converters I collected extensive knowledge in that area.

SPI SID

FPGA Based SPI to SID bridge

SPI SID
The MOS Technology 6581/8580 SID (Sound Interface Device) is the almost 40 year old sound chip that was used in the famous Commodore 64. It uses a 5bit address / 8bit data synchronous bus with a chip select, rw, and clock signal. Since the chip uses the 1MHz (well not exactly 1MHz as I’ll explain later) clock signal also to generate all the audio frequencies, so it is important that the clock signal is stable, even though the read/write access would work fine with a unstable clock as long as the signal setup times are correct. [Read More]

Rockstar

The Art of Code

Rockstar
To understand what this is about you absolutely should watch Dylan Beattie’s brilliant presentation about The Art of Code. Now you know Rockstar is a computer programming language designed for creating programs that are also hair metal power ballads. The famous Fizzbuzz program looks like this. Midnight takes your heart and your soul While your heart is as high as your soul Put your heart without your soul into your heart Give back your heart Desire is a lovestruck ladykiller My world is nothing Fire is ice Hate is water Until my world is Desire, Build my world up If Midnight taking my world, Fire is nothing and Midnight taking my world, Hate is nothing Shout "FizzBuzz! [Read More]

Amiga 2000 (PSU)

Part 2/5

After fixing the Amiga 2000 motherboard it was time to cleanup the power supply. I preemptively wanted to remove all the electrolytic capacitors so I ordered some new ones. Since the power supply is just a single sided PCB, getting the old capacitors out and soldering the new capacitors in would be relatively easy. But this model (later versions don’t seem to have it) has a little daughter PCB that kind of block access and itself also had two capacitors on it that I also wanted to replace. [Read More]

Amiga 2000

Part 1/5

A while back I bought a non-working Amiga 2000 that, according the seller, only displayed a white screen. In the 80’s and early 90’s I only had an Amiga 500, so I thought it would be fun to now get a working Amiga 2000, and restoring one would be a nice X-mas holiday project. Dealing with the Amiga Killer One of the main Amiga 2000 killers is the battery, after 30 plus years they tend to leak and in the worst case can corrode away half the PCB. [Read More]

First PCB Design

PCB for debug adapter

How do you mean I can’t do make clean, fix bugs, make all ? When software engineers make hardware things can only go wrong; notice the size of the switch and the footprint on the PCB. But apart from that, pretty fly for a software guy.

The PCB design was done with KiCad on Linux (but it is also available for Windows and MacOS).

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kicad 

Pacman

RGB LED Display test

First test of a new RGB LED display for a train in Canada. The display has 16 x 144 high power RGB LED’s to make sure it is readable in bright sunlight. The hardware uses a iMX6 CPU and runs a custom Linux OS. Content is send to to display via Ethernet using client specified rail/public transport network protocols. Since it is a multiplex display it is rather difficult to film because the update rate is different from the camera framerate so it looks like it is flickering. [Read More]

Rohde&Schwarz RTM3004

New 4/16 channel Oscilloscope

Since almost every project I did the last decades all use something like I2C, SPI, CAN, RS458, etc. I replaced my old Tek scope with a new Rohde&Schwarz RTM3004 that can do decoding of those protocols, so I don’t have to manually count bits anymore.

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