Not sure why I got this idea, but I wanted to make a 13 segment display of LEDs soldered to a copper pipe and then an entierly way overboard control board with flying wires between components. It ended up looking not half bad, but entierly impractical.
The above video is a nice loop showing it all working in a more snappy animation than just showing some digits. This is after having gotten all the inter-chip communications done. It is at this point that I was really starting to feel silly for having intentionally gone for a dedicated microcontroller per 13 segment section. A bunch of shift registers that could latch the right values in and a microcontroller with half the pins would have been plenty if I was actually trying to optimize the design.
But anyways! Silliness in concept aside, below is a good view of the completed project with it mounted on a board.
Lets talk about the design a bit.
Ignore the giant transformer on the left, that was an afterthought for where to get the power input, but everything right of it that is soldered down is something actually designed and planned.
Continuing from the left, there is a bank of capacitors to smooth out the transformer and rectifier and a basic 7805 linear voltage regulator. The microcontrollers take so little power that I just ran them off of the 7805. The LEDs though take a lot more power and I wanted them to be dimmable without running them on PWM outputs from the MCUs. The blue boards on top of some cork were some cheap pre-made modules. To get enough amperage for the LEDs, I have two in parralel with their outputs and voltage feedback potentiometer soldered together.
Below the adjustable voltage supply is the master MCU. It is the data bus controller and actually does the logic for what the slave MCUs will display. For fun, I also attached a tiny speaker to it. At some point I played around with converting MIDIs to play on the clock, but never got around to implementing it to play the same time as showing the time. Would have been easy to have an internal timer interupt periodically to do multitasking.
Random Gallery of Images
I felt like having a portable game console thing to do some SNES games with.
I had more parts i had to solder together than I originally was planning, but such is iterative design.
I decided a couple years later to take a second crack at it with a different screen. I was more thinking of having a standalone home automation control panel, and so it has only a touchscreen thig time.
In college I had an electric bike that was shared in the robotics club. I probably used it the most, and also did most of the maintence.
I missed having such a bike, and so decided to make another one for myself.
Above is what i ended up with, and below is what I originally tried to do.
Originally i was trying to use a larger capacity lithium iron phosphate battery to get some really long range, but the shape was just too large and so i had to put it on the top of the bike. With it so high up, the bike felt unstable and the kick stand no longer worked. In all, this was not something that worked out, and I went back to normal lipo cells.
My second 3d printer was a cheap knockoff with a lot of compromises. It was a rather fun project to upgrade the printer to make it more stable and reliable. (the first one was so terrible, it is not really worth mentioning)
You can see the final form of the printer with these pics.
The first set of changes was to fix the Z-rods that lift the hot end up and down. The tops would wobble around terribly and the original motor brackets stuck up too high and let the motors wobble around as well. The yellow parts you see are fixing those problems while also making the vertical frame more stable with the plastic parts being a more rigid mounting point. Also I added in a new part for the corneres to have a threaded rod to stablize the frame from wobbling back and forth.
The vertical of the printer was *still* not stable, and so taller printer would get weird artifacts. This lead me to make a second revision of the top of the z-rod holder that would combine the threaded rod holder with it so there was more grabbing onto the frame.
The hot end carraige is something I had to tweak a fair amount to finally get to be consistent.
I did try a 2-filiment color blending hot end, but it was so jam prone, that I never got any actual prints out of it. It was a funny shape to try to make a mounting system for as well.
Eventually after years of good use, the controller started melting on the heated bed connection. I decided to finally replace the whole thing with a new printer, which is something I am working on now.
The main part of the project was to add some speed controlled fans to a server cabinet I had.
I wanted to try my hand at hand crafting a PCB from some copper-clad board and etching away to make traces. The blue covered board is the one that worked, where I gave in and used a laser printer, transparency sheets, and a UV reactive film to make the mask. The black boards was me trying to use spraypaint and a laser cutter to etch away the paint, but the details from it were just too fuzzy.
Also at the same time, a rather quick project of modifying a super-micro case to have quieter fans.
This is the original setup: two computers stacked on top of each other. The fans were quiet, but I wanted it even quieter.
And this is the end result. More space to put random junk on my desks!
The hardware for the monitors and keyboards are in the following pictures.
The one computer (on the left) has a thunderbolt dock, since I need to plug in my wireless headphones and game controller dongle and such, along with having an easy to access SD card reader.
The other computer (on the right) is just a basic powered USB hub and an old usb dac for sound.
I just have a single wall plate with holes drilled in it to route all the cables through. The basement side i have some foam to be strain relief from the weight of the cables.
The server rack with the 'desktop' computers. The two black cases are them, with a NAS on the bottom. (That blue LED really blows out the color on my phone)
The thunderbolt card keeps giving me trouble, like this cryptic error message.
I had a device that took audio input via a 3.5mm jack, but I wanted to play music off my phone instead.
Amazon had some really cheap BT boards, so I bought one intead of figuring out something more complicated.
The first two images shows what I thought would work, but the plastic case didn't have the clearance for the red wires to wrap around the PCB. It was a real quick change to pull those wires back off, drill some holes in the PCB with no traces, and route the wires that way as you can see in the final image.
Felt like learning godot, so made a flappy bird clone.
Play It HereOne of my largest purchases was a knock-off chinese laser cutter. It is a very bulky thing, but has more power than one of those glowforges.
I got the whole thing mounted on a 2x4 and casterwheel thing so I can acutally move it. The 'castors' it has on it do not really work with how tiny they are. Also I needed a shelf on the back to put the water chiller unit to cool the laser.
The pallet it was delivered on showed it was apparently a hard travel trip.
Here is some pics of me trying to dial in some settings and testing different etching settings.
This is me being silly with seeing if it can slice and etch bread. (Yes it did taste like burnt toast, but still totally soft)
The cutter is not just a simple works-every-time thing unfortunantly. The one with the chair was me tring to fix one of my large casters after I snapped a couple screws holding it on. The second one is water leaking out of it from the laser cooling loop.
Wanted a simple box with banana plugs that could have the voltage changed. Yeah, a pre-made one would have been better, but I felt like doing this. The large lever main switch is fun to push up and down at least.
