Hey! I’m Emi, welcome to my site.

I enjoy tinkering with (sometimes old) computers and cameras. Thus many of the blog posts and projects you find on here are related to these. If you are interested in photography you might also enjoy my photo blog.

Spotting Fake BMP280 Sensors

This is the story of three batches of sensors on breakout boards that I ordered over the last few years from AliExpress. All three batches where marketed as BMP280 chips on breakout boards.

The first and third batch worked fine, but the second batch appears to be fake, non-functioning sensors. Judging from a few internet searches there seems to be a fairly common issue of sellers trying to essentially re-label cheaper BME280 sensors as BMP280 since they look similar.

However in my case the sensors did not work and I wasted a lot of time figuring out that the sensors, not the other components in my project where the issue.

So, to hopefully safe someone else some debugging time I’ve added a closeup picture comparison of the fake and of the working sensors below of this post.

The fake sensor (that looks more like a BME280) would just respond to all i2c addresses and then behave badly enough that both micro controllers that I tried ended up crashing upon readout. (Which made debugging harder.)

Left: Fake; Right: Functional

Building a small game in plain Typescript

My little Dotstream inspired game

This June one of my partners took me along to a small convetion called Pfingstakademie. There I attended a workshop on building browser based games, which was quite fun. Given the remote location (and thus slow internet) the facilitators decided to not use many libraries or frameworks. We rather used pretty plain TypeScript and the HTML canvas API. (The package.json.lock ‘only’ has 1700 lines 🙀.) The game I wrote is heavily inspred by a mid-2000s GameBoy Advance game from the Bit Generations series called Dotstream.

You can try it in your browser and the source code is on GitHub. Also you can try the other participants games in your browser as well!

A slightly longer neighbourhood tour

After I creating a very (very) small photo tour in fornt of Kosmos last year I still liked this odd little concept and have decided to expand the tour somewhat! It now allows

This project is very much still a result of the ongoing pandemic for witch it seemed a managebale, if somewaht tedious, thing to build.

If a small virtual neighbourhood walk sounds like a fun thing to explore just press this button here:

Flying from Berlin to Singapore in Flight Simulator 2020

JMB VL-3 Evolution Taking of from Rimini

I’ve acuired a bit of a nerdy pandemic project: I’m playing Microsoft Flight Simulator 2020 trying to make it from Berlin Tegel to Singapore in a very small plane.

This started out in November (right before the actual Tegel airport closed down) after getting a bit of inspiration from a colleague. At the time of writing this I have flown 8 short legs and made it to Rimini. I have put together a small site where you can track my progress, you can find it over here.

A small tour around Kosmos

I recently stumbled across the Roof Tour on elliott.computer. The the very simple, streetview-esque experience (and a lot of the other projects there) reminded me of the early web that I sometimes miss. (Remember when QuickTime VR tours were an exiting new thing?)

It also seemed so very appraochable to make, inspiering me to copy the idea make my on version. You can find the result over here. So far it has just two 360-degree locations but I’m planning on adding a few more points to the tour soon. (Oh, and I even added the 10 lines of Javascript so you can move with the arrow keys, just be aware that it’s all regular links and they will be in your browser history afterwards 😇)

Nintendo Four Score to USB

I’ve recently finished converting a NES Four Score to USB. Overall I think it’s a neat way to adapt up to 4 NES controllers to USB without modifying the controllers themselves. I used a pre-assembled board from raphnet. The result looks pretty neat:

In the process I had to figure out the pinout of an internal connector (CN5). Pinouts for the the standard NES controller plugs are pretty easy to come by, but I guess not that many people build adapters into Four Scores.

I do not think that the Four Score models differed significantly but for completeness sake, here is the board from the model (PAL Ver 1.1 / FPA-PAL-S01) that I converted:

Pinout of CN5

The connector that terminates the cable that goes to the NES is labled CN5. I ended up cutting the cable and using the header and some of the original wires in order to hook up my USB adapter board. You can see the connector with the original plug in place here:

The follwoing table shows the pinout. I got it by testing each pin on the original cable while assuming that the pinout on the contorller port side would be the same as a regular controller. Additionally I’ve noted the names of the pins they need to hook up to on the specific adapter that I used.

pin wire color purpose pin on 4snes
1 brown latch PC 4
2 red player 1 data PC 3
3 orange player 1 clock PC 5
4 yellow player 2 data PC 2
5 green player 2 clock PC 5
6 blue GND -
7 violet VCC +

Mounting the board

Fianlly I had find a spot to mount the PCB of the adapter in the housing somewhere. It’s actually quite small (yay for SMD parts) so that was fairly easy. The biggest change I had to make was to run the USB wire under the original board to my adapter and do the same with the wires from CN5. I was even able to re-use the cable guard form the original. You can see the sticky-tape-mounted PCB inside my Four Score here:

And here is the re-assembled adapter with 4 controlelrs plugged in for testing: