A couple of months ago I managed to find a used DSLR body for a very good price at a local flea market. I had been thinking of getting a proper DSLR for some time now (so far I’ve been using a “bridge” camera, the Fujifilm S9500), so for only £30 it was worth the risk. What I got was a Nikon D100. This is a fairly old, 6 megapixel DSLR, which cost about $2,000 when it came out in 2002. I primarily got the camera to use it together with my telescope for astrophotography, and for that it didn’t need to do much. However, now that I had the camera body, I also wanted a lens. With Nikon being one of the two big DSLR manufacturers (Canon being the other one), it didn’t take long to find an inexpensive used lens on ebay. When I tested the lens with my camera body, it became clear that something didn’t work properly. While autofocus worked fine with the lens, whenever I wanted to use even a slightly smaller aperture (with F-numbers as low as 5 or 6) the camera displayed an error, and depending on how high an F number I had dialed in, the image tended to over-expose. I decided to investigate.
Record player modification
A few weeks ago I bought a record player for a few quid at the local flea market. Even though we already have a nice vintage Marconi record player that's in great shape and sounds fine, it has two disadvantages: 1) There are no external connectors, … [Continue reading]
Using the DMA controller on STM32F4
A little while ago I got one of the fairly common "Nokia 5110" LCD modules, a 84x48 b/w graphic LCD screen, thinking it would be handy to have in current or future projects. One of the things I especially like about this module is that it is using a … [Continue reading]
STM32F4-Discovery MIDI input and basic synthesis
After the flurry of activities in recent weeks on a previous post (thanks guys!) I finally went back and worked on the synth project some more. Some time ago I had already created a simple MIDI input and output circuit on a stripboard that the … [Continue reading]
Identifying the controller chip on an LCD module
I recently got a cheap 20x4 LCD module on ebay and started playing around with it this weekend. Of course, given that I paid less than 5 pounds for it (incl. shipping from China) it came with no documentation or other information, but I hadn't … [Continue reading]
Configuring the STM32F4-Discovery for audio
What made the STM32F4-Discovery board so attractive for me was the fact that it comes with a nice on-board Audio-DAC with integrated amplifier, the Cirrus Logic CS43L22. However, getting the combination of STM32F4 and CS43L22 to produce any sound is … [Continue reading]
Hello STM32F4-Discovery
One way in which it's easy to tell that I'm still relatively new to the whole electronics and microcontroller hobby is by the amount of new developments in this area I tend to miss until much later. One of those is the release of the … [Continue reading]
VCR capstan control with ATmega328P
I like taking stuff apart, especially stuff with electronics in them, so when I saw an old VCR next to a trash bin in the alley behind our house, I had to take it in. There are obviously quite a few interesting bits inside a VCR, both mechanical and … [Continue reading]
PSU conversion to bench supply
A few weeks ago I did what I had wanted to do for a long time: take the old computer power supply I had laying around and convert it to a simple bench power supply. There are plenty of instructions on the web on how to do this. The idea behind all of … [Continue reading]
Acorn RISC Machines infomercial
This was posted on Hack A Day today, and it seems an appropriate first post for this blog. It clearly captures one of my interests, namely digital processor technology (and a little bit of their history). Today ARM (now standing for Advanced RISC … [Continue reading]