Charger – battery compatability

For a project this set-up was bought:

It consists of a Polymer Lithium Ion battery (3.7V) with a capacity of about 400 mAh and a LiPo Charger Basic – Mini-USB.

Now, for another project we have a Li-Ion recheargable battery, 3.6 Volt
(for example this one)

Now, the question is if the button cell battery can be charged with the LiPo Charger Basic?

You’ve got the power

For almost all devices we use power supplies which transform AC into DC, adapted specifically to the power needs of the device.
This 9 pages in depth post about power and power supplies has been travelling all over internet. Jon Chandler specifically speaks about Wall Warts, the ones who transfer AC to DC.
His article was featured on Hackaday and Makezine – but I thought that for future reference it’s nice to write a little about it on Ellentriek.

power supplies

Important stuff!

Codes, colours and conventions

When you open up an electronic device, you are confronted with quite a lot of colours on the components (especially when the device has a certain age – smd components unfortunately are less colourful).

“The electronic color code was developed in the early 1920s by the Radio Manufacturers Association (now part of Electronic Industries Alliance (EIA)), and was published as EIA-RS-279. The current international standard is IEC 60062.

Colorbands were commonly used (especially on resistors) because they were easily printed on tiny components, decreasing construction costs. However, there were drawbacks, especially for color blind people. Overheating of a component, or dirt accumulation, may make it impossible to distinguish brown from red from orange. Advances in printing technology have made printed numbers practical for small components, which are often found in modern electronics.”

Resistors, for example, have three bands of colour indicating their value in Ohm – the fourth band indicates how accurate these values are. Knowing their value is essential, even already for basic electronics, because they control the voltage passing through your electrical circuit.
You can learn the values of these colours by heart, or you can use little helpers, who come in several shapes and sizes.

– There are lots of online resistor calculators

– I’m quite a fan of this resistor calculator:
cardboard resistor calculator

– There are good looking apps, such as this ElectroDroid.

When you use leds, having the right resistor at hand is very necessary, because when it gets too much power it stops working.
So, of course there are online calculators for leds!
Even thermistors have their own calculator.


Arduino, Processing and sensors Part 2

In my search for up-to-date tutorials on connecting sensors to Processing I found a few valuable threads.
They are clear, the code is GPL, the aesthetics are – well I guess not my taste – but opinions are very easy to get by – good tutorials – less easy to find (=a critical compliment). Jeremy goes a step further than the usual Hello World “Blink a led sketch”. I didn’t do what he does at 20 years old.

He starts with an introduction to Arduino:

In tutorial 6 he already goes from receiving information from a sensor to sending out serial information for Processing to receive.
Tutorial 7 continues on this visualizing sensor information thread.

These two tutorials combined with this one from the Arduino playground website, will hopefully enable me to visualize my flex sensor data – my deadline is tonight. (GloupsGulpSlik)

Found through the use of a search engine and this blogpost.

Forum and real life hackerspace help

I had quite a lot of trouble making a waveshield (a soundmodule) and an Arduino Mega work. 20 real life buttons need to trigger 20 sounds, without the involvement of a computer (it’s an installation for here). As I was using a big Arduino, the usual easy connection had to modified, which has quite some consequences on the code level and how the sound was played. An unwanted effect was distortion on the sound whilst it was playing.

In this Forum post I explain the problem – and post a possible solution as well.

Thanks again, Gregor, Brussels Hackerspace and Leandro!