Tuesday, June 29, 2010

BalanceBot

I decided on a new project while at circuit hacking night at Artifactory last night. In my head it looks something like an unmanned segway…

For the controller I’ll be using an Arduino Duemilanove that I already have, and the accelerometer will be an ADXL345 3 axis accelerometer with a SPI/I2C digital interface. It seemed less than elegant to me to use an accelerometer with analog outputs as a digital signal would need to go through a D/A converter before travelling through a length of hookup wire then through an A/D converter where it can finally be used by my program in the Arduino.

So my first step is going to be getting data from the accelerometer to the Arduino, and not knowing the first thing about SPI or I2C is going to make this a steep learning curve!

I’ve created a BalanceBot library in Eagle and created an ADXL345 device. This should allow me to not only create a schematic for bread boarding but a PCB later if I’m so inclined.

Monday, June 21, 2010

Remove Linefeeds from an Excel Document

I recently received an Excel document that needed to be massaged to suit the requirements of a DCS. One of the changes required was the removal of line feeds from within cells.  There were over 500 rows nearly all with multiple line feeds so I did not want to do this manually.

Some googling revealed an easy way to do this and a cool new tool to try – immediate mode in VBE.

  1. On the Excel worksheet select all cells that may contain a line feed to remove
  2. Open VBE using alt+F11
  3. Enter Immediate mode by pressing ctrl+G
  4. In the Immediate box type Selection.Replace Chr(10),”” In Immediate whenever you hit enter your command is executed.
  5. Go back to the worksheet and all line feeds are removed

Note that the argument for the Chr function is a char code. Char codes are the same as ASCII codes for the first 32 control code characters so line feed is alt+0010 or Chr(10).

References:
http://www.ozgrid.com/forum/showthread.php?t=20451

Monday, June 14, 2010

GanttProject

In a previous post I mentioned that I was looking into open source project management software. I was a little sad to find that most of the software I tried had one glaring oversight or another. The program that I tried initially and then kept coming back to was GanttProject.

The GanttProject features that I use are:

  • Gantt chart
  • Linking (start-finish, start-start etc.)
  • Resources can be created/imported and assigned to tasks. Resource utilisation is calculated automatically
  • Completion tracking on the Gantt chart

This is a simple feature set and by far the best of what is on offer from the open source world for project management.