In my previous article I briefly showed the way I store and organize my SMD components. Even it is way better than storing parts in labeled plastic bags, in which the parts are usually shipped, it is still far away from being perfect. I was already looking for a better solution for a six months or so, when I finally found two products, which seemed like a possible solution – Aidetek Box-All Cases and WenTai Boxes.
I use SMD components in my projects whenever it is possible. I like when things are compact, look professional and also I hate drilling PCBs. Also many modern components aren’t available in other packages. However with bright sides of SMD components comes the dark side — the storage.
You need several hundreds type of components to do something meaningful. The components are small, come in similar packages usually with no labeling (capacitors, inductors, SOT, QFN — all of them have no, or at least not fully descriptive label). Putting them in a one large bag isn’t a good idea. Once you loose track what kind of component is it, you can throw it out. Sometimes it can be measured, but usually the time doesn’t worth the money.
I used to keep my components in the original carrier tape, usually with a handwritten label. All the tapes were in several plastic bags. After my collection of components grew up a little bit, this kind of storage was unusable. Lookup a component of a particular type was time consuming, reading small, often blurred hand-written labels, was a pain. Maybe you know it by yourself.
GPS is a really nice and quite cheap technology – unless you want accuracy in orders of decimeters or centimeters. Yes, there are high-accuracy GPS receivers which can achieve such an accuracy, however the price of the cheapest one is starting at $500. Not really a something a hobbyist can afford/is willing to pay for.
For many application there’s no need for absolute position, a relative position of 2 or more GPS receivers is sufficient. Take an autonomous robot moving in outside area as an example. You can setup a fixed ground station and navigate it relative to it. The intuition tells you that measuring relative position should be more accurate (when we’re talking about station less than 500 m away from each other) that measuring the absolute position int the WGS-84 system.
Why? The most of the GPS receiver’s accuracy depends on the atmospheric delay (the time the GPS signal travels through air) and it should be pretty much-less the same in a small ground area. So, having two the same GPS receivers, which uses the same antennas and algorithms for position measurement, should produce the same results, right? Well, kinda.
There are many papers out there about relative GPS position measurements. I’ve read several of them and none of them and I have to say they were bad. All of them were very shallow with lots of motivation and no results (don’t even think about public implementation!). I gave up reading (for now).
Almost daily I come to problems I’ve seen before. Usually I have solved them successfully, but I struggle to remember the correct and effective solution when I need it again. I have also created lots of gadgets and devices, which usually after some time end up stacked in a box. And no one, even myself, think of them again. I think it’s a pity.
This is why I decided to start this blog, called “mind.dump()” – to make a dump of my mind, thoughts, ideas and experiences. To archive them, make them searchable and also to share them. I profit a lot from others’ experiences, they shared, in my work, so I think it’s right to do the same and possibly to help others.
Expect posts about programming, electronic, computer science, robotics, CNC machining and others.