Portfolio || projects
Chronological list of various projects I've been working on over the years that I'm allowed to speak of (which, unfortunately excludes some of the more exciting $WORK stuff).
Thrust stand for characterization of model rocket engines and RC electric motors (2023)
This device is designed to measure thrust and chamber pressure of model rocket engines and also performance of RC electric motors (thrust, power consumption). ESP32 is used for wireless connection, so the device can be placed in a safe distance from experimental setup.
Machine vision system for detecting wood board orientation (2016-2023)
Designed and implemented a machine vision system for wood-working industry. The system detects the grain direction of the wooden boards and turns them around so that all boards are processed with uniform quality.
Client was so impressed with the system and has since ordered several more machine vision systems similar to this one.
The first software iteration used hand-crafted computer vision routines but a later iteration was developed which uses a simple neural network to classify acquired images. The very latest iteration is being developed with in-the-field fine-tuning/re-training ability (i.e. an operator performs the annotation of the training data by pushing a button when the board is not in it's correct orientation).
More details: kadikisav.lv (in Latvian)
Logic analyzer probe for Rigol MSO5000 (2023)
Open source hardware design of a logic analyzer probe for Rigol MSO5000 mixed-signal oscilloscope.
Details: design on Github
Bipolar constant-current switching power supply for thermoelectric cooler control (2022)
This power supply was built for small temperature controlled chamber intended to test the functionality of electronic devices in various temperatures. It features a software-controlled switching DC-DC regulator with up to 20A output current and ability to control polarity of applied voltage. Unit is controlled via optically-isolated serial port with SCPI commands.
DIY x-ray inspection machine (2022)
Home-built x-ray inspection machine- consisting of surplus dental x-ray imaging source and sensor. Steel enclosure, lined with lead sheet (overkill according to safety technician but that's better than underkill here). Custom electronics and firmware for driving the x-ray source and acquiring data from sensor, with python-based acquisition tools on PC.
Details: Google Photos album, acquired images
Airguard- DIY CO2 monitoring electronics kit for education
Participated in a non-profit project which designed, manufactured and shipped a few hundred electronics kits for mid/high schools. After assembly by end-user the device measures CO2 concentration in air and warns if it exceeds threshold. My primary contribution in this project: firmware for micropython running on ESP32.
Details: project website, GitHub repository
Machine vision system: board length measurement (2017-2021)
Hardware and software system that measures length of wooden boards moving on conveyor. The system was built on a hardware that was designed as low-cost "smart camera" (i.e. self-contained computer + camera bits, which directly interfaces with other equipment).
Details: Google Photos album of development
Wireless vibration measurement and analysis solution
Developed a small battery-powered, wireless vibration measurement and analysis solution (ESP32 + MEMS accelerometer/gyroscope). GUI tool performing basic analysis (essentially, just FFT) written in Qt.
Wireless temperature & humidity logger (2017)
Hardware and firmware design for battery-powered temperature and humidity logger (ESP32 WiFi module and Si7021 sensor). Hobby project for personal use.
Simulation environment for robotics (2016)
Developed a rigid-body dynamics model and interface to simulation platform for inverted pendulum robot. The simulation platform allowed quick experimentation with various control algorithms without building actual hardware.
MAVLink to WiFi bridge (2016)
Developed hardware & firmware for MAVLink serial protocol to WiFi bridge. This device was small enough to fit inside small UAVs and powerful enough for 1MBit/s telemetry stream over WiFi network.
Not a great hit commercially, but several of the produced devices are used by large North-American aerospace organization for UAV development.
More details: imprimus.lv/mavlink
Firmware development for quadrotor flight controller (2015-2017)
Firmware development lead for quadrotor flight controller:
- STM32 hardware bringup, drivers for additional sensors, firmware customization for selected hardware, debugging,
- Sensor fusion (optical flow for indoor navigation), control loop for obstacle avoidance based on multiple distance sensors,
- In-air startup feature (quadcopter starts automatically when thrown up in the air),
- Various tools for testing, sensor replay in simulator, supporting ground control software team.
The project was canned before public release :(
Small thermal-imaging camera with analog video output (2015)
Firmware development for thermal-imaging camera (based on FLIR Lepton sensor and STM32 microcontroller).
Volvo MELBUS emulator (2014 - 2015)
An emulator for Volvo's head units, to give it aux in capabilities. Hardware design based on Atmega328p. Hobby project for personal use.
Links: wiki, repository browser
DLP based 3D printer (2014 - )
An ongoing quest for a better 3D printer. First iteration of both software and mechanical side of things. Has printed first parts already.
Links: G+ album
Software for a prototype 360° image capture system (2014)
Software for Linux-based SBC, controlling DSLR (entering required settings, triggering shutter, feedback about battery etc) and controlling digital-communication servo motors.
RepRap2X (2014)
I've built a few RepRap 3D printers in the last few years (original Mendel, two Mendel90) and I wanted a larger, more rugged printer, which Just Prints.
Mechanical design in CAD (SW), mechanical re-design (hehe), assembly, wiring, configuration. Auto bed-leveling calibration (still somewhat in progress).
Links: G+ album
Automation of HVAC system (2014)
Industrial automation project for a woodworking company- automation of their newly installed HVAC system (managing temperature and humidity, balancing a positive air pressure in select rooms). Siemens S7-1200 + Siemens HMI. Custom web interface for management.
Eggbot (2014)
Just a for-fun project for Easter 2014- a device which draws Egg decorations.
3D printed parts courtesy of Glasswalker, custom electronics design based on Arduino Mini Pro.
Links: G+ album
Desktop CNC engraver (2013)
Wanted a mill, got an engraver. Designed in CAD, inspired by designs on internet. Now has gotten a proper spindle and is even usable for light machining work: Dibond, plastics, PCBs.
Postal package tracker (2013)
A web-based tool to notify me when my stuff arrives in local post office. Written using Django, scrapes pasts.lv for the data on packages.
Links: source code on GitHub, hosted version of the tool
RaspberryPi based car navigation retrofit (2012 - 2013)
Retrofit of Volvo's (~1998-2005MY) stock navigation unit with RaspberryPi, running navit. Interface with car's CAN-Bus network to pass button presses on steering wheel to RPi.
Electronics design, firmware on AVR microcontroller, configuration and UART-to-HID driver on RPi.
Links: HackADay, source code on GitHub, wot.lv, G+ album
Website to make photos of lost places accessible - zudusilatvija.lv (2011)
A website which displays photos from the archives of Latvian National Library. Subcontracted work for Latvian National Library. My role was developing backend + frontend software.
Links: zudusilatvija.lv
CNC plasma cutter - software and motion control (2010)
Dad built a CNC plasma cutter, I brought it to life- simple as that. Upgraded to custom-built torch height controller in 2014.
Web-app company - groupscript.net (2010 - 2014)
Co-founded a company which sold PHP e-commerce software mostly authored by me.
My role could be described as lead-developer who also got to manage a team of 5 other developers.
Experience gained: immense knowledge of web payment systems, how to write PHP software to be hosted on myriad of web-servers out there and how not to write an e-commerce software.
Got to build in-house tools for order processing, release packaging etc.