XInC2 Dev 2
Also called MistConnect, it is a sensor platform that can connect to almost any sensor and send its data to the cloud.
Contained LTE, LoRa, GPS,and a custom 2.4GHz protocol (mcAir). From a design perspective, the most interesting things were the
power system and how so much functionality was loaded into each of the 8 sensor pins.
I've worked on a few projects that are covered by NDAs. Permission was given to say the following.
A fridge meant for offices or communal kitchens. Multiple individual locked compartments that could be opened from your phone. Each compartment had a small daughterboard PCB that measured temperature, sensed if the door was open, and controlled the lock. They all connected to a motherboard with muxes and IO expanders. The motherboard had LTE functionality and some relays that let it control the mechanical parts of the cooling system. It was powered through mains AC voltage or a battery backup with circuitry to switch between the two seamlessly.
Sensor Grid Reader
A device that read pressure data from a grid array of resistive pressure sensors and sent it to the cloud via the LTE network. I did the electrical and mechanical design. I was pretty proud of the mechanical design because it was complex and came together cleanly the first time. No design revisions were needed.
Outlet Mount IoT Gateway
A small LTE IoT gateway that could be plugged into a wall outlet. Involved working with a mechanical designer to fit the electronics in a custom enclosure.
Eventually all my project logs will be moved here, but for now they can be viewed at hackaday.io/adamgulyas.
A modular synthesizer voltage controlled oscillator based on a schematic I found in an old magazine
article titled "Inexpensive voltage-controlled oscillator is rich in harmonics over entire audio range".
I built a breadboard version during a Hackathon in 2016, then decided to finish it. The magazine
article circuit had two flaws in it. The 555 timer was hooked up wrong to be a schmitt trigger and
the BJT invertor had a resistor in an incorrect position. I replaced the 555 timer + bjt with an
op-amp to simplify things. When debugging the original circuit, I found it really helpful to seperate
each circuit block and feed dummy signals into them, then observe the output. I kept that ability in
the PCB as well with the three jumpers. I wrote a whitepaper with the algebraic analysis of the
integrator because it's non-intuitive why switching in that resistor would reverse the output.
Project Log. Original Schematic. My Schematic. Spice Simulation Integrator Whitepaper. News Article.
A Eurorack synth module that outputs four controllable DC voltages. Project Log.
Synth Power Bus
A board with a bunch of Eurorack power headers.
A gift for my wife. The custom nixie tube was made by Dalibor Farny, who was kind enough to humor me. The schematic was based on a boost regulator by Nick de Smith. The wooden enclosure was made by a CNC shop from plans I drew. The whole thing was 3D modeled to make sure it would fit together. Project Log.
An eight note piano to test small scale production. Project Log.
Audio IO Switch
Two TRS jacks on either side of the box. The switch on each side can choose which jack is fed through to the other side. Completely passive, so there's not a defined input or output side. The main challenge was getting everything lined up mechanically. Project Log. Github repo.
A power resistor decade box without any mechaincal UI elements. Can sink up to 3A at 24V over the entire resistance range. Intended for testing power supplies. Made to be easy to assemble. Project Log. Github repo.
Atari Punk Console
My take on a classic noise maker with a view towards mass production. Project Log.
Relay Puzzle Box
An entry for the Engineering Art Show I did while still in university. I presented it as a puzzle box. The light bulbs turn on
in a seemingly "random" order in response to the switches. It's really just a two bit full adder. I made it before I had any experience with PCB design, so
the inside is a mess of wire. I'm quite proud that, in all that chaos, I was methodical enough that it worked perfectly the first time I turned it on. I had
hoped to get a satisfying series of relay clicks when changing state, but they all happen near instantaneously. In the future I might make a PCB for a 1 bit
module that can be connected in series to add arbitrary length numbers.
I didn't look up how to make relay logic gates, instead deriving them by hand. You can see all the different variations I came up with in the log. Project Log. Demo Video.
I was once requested to breakout a distance sensor for a firmware dev to prototype with. It came out pretty clean.
Embedded C Class: Lab 10
An Altium schematic library for E24 5% 0603 Yageo RC Series resistors. I find it annoying to make standard resistors as I need them. I'd rather spend a few hours and export data from Digi-Key then mass import it into an Altium library. Since searching for values "alphabetically" is kind of annoying (where 47Ω comes after 10kΩ), I put the decade number at the start of the symbol reference so Altium would automatically order them by increasing value. Github repo.
Passives 3D Models
I couldn't find the perfect 3D models for resistors and capacitors. Either they were exported weirdly and had odd facets, or the origin was weird and they would sometimes hover above the pads (but only sometimes), or they were too complicated. So here's some I made myself based on my favourite series of parts (Yageo RC_L and CC). Links to download zip files of the parts are below.
Designing and testing a 2.44 GHz patch antenna. Project Log.
At one point I spent about a year as a carpenter's apprentice at HERR Window & Door. In that time I built custom doors and windows, including the hinged egress windows shown on their site. It taught me to be methodical and precise, and to always be thinking about how what I was currently doing would affect the next steps in the process. Although I didn't take any pictures of the doors I made, below are some of the things I built in my own time.
Lyre made with wood from Home Depot and reused guitar parts. An entry for one of the UofA Engineering Art Shows.
Wands turned on a wood lathe. An entry for one of the UofA Engineering Art Shows.
Maple with cherry insert. Finished with Danish Oil. This was a Christmas gift for my Grandparents.
Maple with cherry insert. Finished with Danish Oil. This was a wedding present for an old boss that turned out to be not a great person.
Maple with cherry insert. This was a failed project. I made a mistake with the lathe chisel and had a pretty bad gouge. Part of the tenon broke and it flew off the chuck. I couldn't remount it. It was supposed to be a gift, but now I just keep my keys in it.
Tal'Dorei Hex Map
A hex map based off of Tal'Dorei. Nov 2020. The full map can be viewed here: Source Files.
A desktop background inspired by PCB routing. Download.