I have a drawer cabinet near my front door. It’s top drawer has become my “messy drawer” and holds keys, bags for grocery shopping and face masks. And also, tens of (found) bicycle lights, a TomTom one I have not used (nor updated) since 2009, and a garbage pass for a municipality I don’t live in for almost 10 years.
I could never quickly find my keys.
Continue reading “Key organizer from old shoes”Since I lived in Belgium (from 2002), I have always carried my passport with me; it was mandatory there and it stuck. I never owned an ID Card. I have this in a pouch that originally belonged to my Rand McNally Streetfinder III Navman GPS unit. This was a GPS receiver that clicked onto the back of a Palm III (see ebay for example, as long as it’s available). I have long thrown away the Navman, but the pouch has been doing passport duty for 20 years, but it started to fray and tear apart. It was good, but I missed two things:
I used to have a Raspberry Pi B (model 1) act as my NAS.
The PI (or probably it’s memory card) died on me, and I’ve always been appalled by it’s slow, slow data throughput, so I ordered a new Raspberry Pi 3B+. Literally two days after it ordered, the Pi 4B+ was announced. So I ordered that one too.
Finally, I have some time to put it together.
What I want is basically the same as the old:
I love the website Cartesius, which has a trove of old topographic maps of Belgium.
One of the maps that I consult the most is a stitch of all topographic maps of Belgium of 1969, zoomable and pannable like openstreetmaps.
However, lately, the site has been acting strangely. The front portal continuously reloads, so it is hard to select anything. This has been going on for months and has not been fixed — so I guess it is no longer actively maintained, with bears the risk it might go offline soon.
Therefore, I wanted to download these maps for backup, if possible.
A list of all things railway-related I put on openstreetmap (since october 2021)
Sadly, there is not one single reason for the housing crisis in the Netherlands, or we could — with effort — fix that problem. There are reasons that have been building since the 1980’s.
In a recent discussion I came up with the following reasons for the housing crisis that each for themselves would not be too bad of a problem, but combined they form this cluster bomb:
I have a fridge I bought in 2009. In the door, there is a tray that holds heavy items like yoghurt cartons. That tray was held up with two tiny tabs on each side, which fall in a slot in the side of the tray. In 2013, those tabs broke off, which rendered the tray unusable. This means I had to put those cartons in the fridge proper, blocking access to the vegetable drawer (I had to remove all the cartons to access it) and making access to the bottom shelf more cumbersome.
This is annoying.
Ik heb in 2009 een koelkast gekocht. In de deur zit een rekje waar de zware dingen zoals yoghurtpakken op staan. Dat rekje werd vastgehouden met twee kleine tabjes aan elke kant, die in een sleuf aan de zijkant van het rekje passen. In 2013 zijn deze tabjes afgebroken, waardoor ik het rekje niet meer kon gebruiken. Dit betekende dat ik de yoghurtpakken in de koelkast zelf moest plaatsen, waardoor ik niet meer bij de groentela kon (ik moet alle pakken uit de koelkast halen voor ik hem open kan maken) en ook niet meer makkelijk bij de dingen op de onderste plank.
Dit is vervelend.
I found an old beaten-up CD player a while back, and decided to take out the human interface card, with the LCD and buttons on it.
In a previous episode, I managed to get the LCD to do something. Now, I will try to let it do exactly what I want it to do!
The first task is to find out what segments is controlled by what segment to the chip(s). In Controlling the card, I found out how to send the chips data — basically I have to send an 80-bit sequence to the two chips, of which 2*4 bits are chip control data. This leaves 72 bits of data to control 57 segments, so some of the chip’s capacity was unused.
My first plan of attack is simple: in the previous episode I learnt how to listen for keypresses, so my idea was to make a simple keypress-driven loop trough all the 72 data bits, to see which segment will light up.
Continue reading “Using the LCD”Now that I deciphered where everything goes and how everything works, it was time to make sure I build a foundation to make the I/O a little more usable, instead of fetching raw data. Fist stop: make the input buttons accessible.
Working with keypresses is actually not as simple as I intuitively thought. If you have one button attached to one input pin and do a simple digitalRead(pin);, then you know your button is pressed. But if you want to do an action only once on every key press? You could have a little variable that keeps track of whether the key was not pressed last time and is now — basically working on the leading edge. But then you still have the problem of key bounce to take care of.
And what if you want to detect long presses (e.g. to go into a settings menu) or held presses (press once to increase a counter, keep pressing to keep increasing it)?
But first, the basics, how to detect a simple keypress with the scan matrix used in this board?
Continue reading “Scanning keys”I found an old beaten-up CD player a while back, and decided to take out the human interface card, with the LCD and buttons on it.
In a previous post, I found out where all the connections on the PCB go and how they connect the buttons, LCD and chips together and what they do. Now, I will try to see whether I can control them.
Continue reading “Controlling the card”
