Monday, September 4, 2017

Fan-Tas-Tic Pinball, Part 8, LED - display!!!

I've finally received the 32x32 panels in the mail and started assembling the play-field screen. Seeing this thing come together was a real joy!

I made some brackets from scrap wood to precisely align the LEDs with the pixel grid, which worked out quite well. And yes, no joke, right now the panel is mounted with fishing line.  


The panel is driven directly from the GPIO ports of the Raspberry PI. This is possible thanks to hzellers LED library. The 3 ICs on the adapter board are TTL buffers for 3.3 V to 5 V conversion. On the right is the complete Fan-Tas-Tic controller board including all PSUs, mounted on a wooden plank

I'm quite happy with the way it turned out. Especially adding the diffusor sheet from a LCD screen and replacing the window with tinted acrylic gave it exactly the stealth and pixelated look I was after. This is especially obvious in the video below, where I put it all together:

Next step is integrating the screen in the Mission Pinball framework and finally coming up with some  game-rules, graphics and sound-effects.

Sunday, August 20, 2017

Hydroponic Veggies Part 3 -- Calibrating the PH probe

Step 1: Buy calibrated PH buffer solution (at least 2 different reference points are needed)

Step 2: Dip the probe in, log the raw values

Step 3: Install Python and calculate correction values

Here's the Jupyter Notebook I used for that purpose


Saturday, July 22, 2017

Hydroponic Veggies Part 2 -- The water level sensor

The initial idea was to stick a VL53L0X TOF distance sensor to the reservoir lid and get the water level from there.
Didn't work out. Not enough light reflected from the water surface lead to super flaky readings. What did work out in the end is this ...

Thursday, July 6, 2017

Fan-Tas-Tic Pinball, Part 7, Back to a LED - display!

The original Fan-Tas-Tic machine had a mechanical roulette wheel assembly, visible through a window in the middle of the playing field. For some time now I had it replaced with a 1280x720 LCD panel.


However, I'm not completely happy with this configuration and recently decided, the LCD panel has to go! 

Monday, July 3, 2017

Hydroponic Veggies

The goal is to grow tomatoes, chilis, carrots, lettuce and spinach on my balcony. It shall be hydroponic and as much automated as possible. Here's my setup so far ...

Plumbing and Dutch-buckets

No rocket since here. It's all made from 1/2 inch PCV pipe and fittings from the hardware store. The buckets were done according to these excellent instructions by mhpgardener. As I wanted the setup to be removable, I didn't use any glue. To achieve a good seal anyway, I used a bit of silicone grease on all fittings. So far it holds up fine.


Sunday, May 1, 2016

Fan-Tas-Tic Pinball, Part 6, EMI trouble!

This is going to be a little story about electromagnetic interference (EMI). The good thing is: there will be a happy end :)

Having installed all the WS2811 LEDs, I decided to play a quick game to see if everything is still working. It was quite surprising to see the LEDs flicker like a Christmas tree, even though they should have been dark. This happened everytime the flipper coils actuated. Clearly there was some kind of EMI problem, inducing noise on the data line of the LEDs.

A quick scope measurement on the solenoids revealed the issue:

Saturday, April 16, 2016

Fan-Tas-Tic Pinball, Part 5

Adding some LEDs

I did a quick test with the WS2811 LED strand and I'm quite satisfied with the results. They are slightly brighter then the original bulbs, consume far less power and hence don't get hot. Especially under the white playfield inserts, the RGB colors look fantastic. The red inserts filter out all the other colors, so it only makes sense to have these LEDs configured for red only -- but that's not a big problem, considering how cheap those LED strands are.

I started to work on a platform driver for the Mission Pinball Framework v30. There is some basic functionality already -- but still some bugs need to be resolved.