Earlier this year I embarked on the journey of designing a simple but expandable robot that any electronics enthusiast could build. I knew several nice kits from brands like Lego, Makeblock, OWI Robotics, etc, but I considered them to be normally either too expensive or too simple and limited. There are also many generic unbranded kits on eBay which suspiciously […]
Not long ago I purchased a few 320×240 touchscreen displays from ebay that looked pretty decent and were also fairly cheap. They conform to the Arduino shield form-factor, so they snap directly onto any standard Arduino board, making them really easy to test and use. They also have an integrated microSD slot (connected to the same bus used by the display controller) which is a nice touch and widens […]
I used to have a small desk clock that I purchased for a trip. It was cheap but it had some really nice features that I quite liked. It had large digits that I could see from my bed each morning, and it was also able to measure and display the current room temperature, which I always thought […]
So in a previous post I’ve discussed how to communicate with a custom HID device using libhid and a Raspberry Pi running linux. This post is a sort of sequel. I’ll talk about some of the issues and nuances I found when working on a more complex (but related) project; In this case a Composite USB Device that I had to implement on a […]
I wanted to add a temperature sensor to a project I’m working on, and while I already had selected the perfect IC for the job, I decided to test a couple of other options I had, to see how they fare in comparison. I was originally going to compare only 3 sensors; the popular LM35, the not-so-popular LM335 and the […]
If you have any experience with a soldering iron, or soldering electronic components in general, I’m sure it will come as no surprise for you that the “fumes” produced by the process are not exactly good for your health. They can be quite harmful in fact (** depends a bit on the chemical composition of the solder you use). Even […]
Background Back in the ’80s, Casio produced a line of calculators that was sold and advertised as “pocket personal computers”. This branding started with the PB-100 I believe, but the device concept started with a previous model, the FX-702P, produced in 1981. While by today standards that claim seems a bit of an stretch, it held quite a bit of ground back […]
As part of a bigger project (that I’ll reveal later) I set on the journey of designing a simple “keyboard”. It needed to have enough keys to be usable as a general purpose input device (so it requires alphanumeric chars, common symbols, ENTER, ESC, etc) and preferably built around components I already had (like the bunch of 6x6mm push buttons that I don’t […]