Testing laptop battery: pinout, SMBus, charge capacity

Introduction:

As a result of visiting Hamfest, I ended up with a laptop to take apart – a fairly new Toshiba Satellite C675D with a broken screen. It’s not a Hamfest if you don’t bring home something to take apart of course! Today we’ll be testing the battery it came with to see if it’s salvageable.The date code says  it was made in 11/2011

Patient all hooked up

Patient all hooked up

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Atmel QTouch tuning using Saleae Logic16

I happened to use an Atmel Qtouch chip in a project recently. The particular part was AT42QT1040, used in a fairly typical application- replacing four tactile buttons with four touch buttons. The chip is literally a “black box” that you give power, connect a few passives to the electrodes and in return you get four digital outputs representing the status of each key. No software to write, and is very simple. This particular feature came up very handy when a customer recently decided to switch from tactile to touch buttons mid-design. Since I was using Altium Designer on this project, the electrodes were essentially a freebie for me. I simply used Atmel Qtouch library, added the rectangular buttons into my schematic as components and Continue reading

TI Launchpad Booster Pack footprint library for DipTrace

Today’s post is a small DipTrace library i created for some TI Launchpad Booster Packs I am working on. It is modeled after a similar Eagle library posted on www.43oh.com forum.

There are two schematic symbols and three footprints:

Full size covers the whole Launchpad footprint

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DipTrace layout and ordering boards from Dorkbot aka OSH Park

Well, my test design is complete and now I need a few prototypes to play with. The usual ways of ordering PCBs are rather expensive, with just tooling fees in hundreds of dollars. The remaining options are a few China based places such as Itead Studio, Seeed Studio ,PCB Pool and Batch PCB ran by Sparkfun, and an OSH Park ran by Laen from Dorkbot. He runs a community PCB service that groups orders and orders them periodically on a common panel, sharing costs between all people. The cost is very reasonable ($5 a square inch) and you get three boards. So a 2 square inches board in three copies will cost you $10 delivered from a US based board house! That definitely opens the door for quick prototyping of pretty much anything! After having used other company’s prototyping services, I must say OSH is also by far the most user friendly. Lets walk through the steps of ordering these boards. Continue reading