Updated the hardware page

I’ve updated the hardware page with what I’ve bought and used so far.

I expect two more major expenses (meaning > $10): The 5V rechargeable battery and possibly a new platform.

Progress

Lots of stuff has happened since last update. To start off, I received my L298N motor controller. It was relatively easy to hook up and I am now able to control the two DC motors!

Also, I received my CyberPower CP-H420P powered USB HUB. This allowed me to finally connect high-power USB devices such as a wifi adapter and a webcam.

The L298N controller does absorb a bit of the power to the DC motors, so I had to replace the 3xAA battery pack with a 4xAA one (from 4.5V -> 6.0V) to get adequate output from the motors.

The wifi adapter (TP-Link WN722N) was easy to set up. It works great and now connects on startup without any problems.

I’ve only tried one webcam (Microsoft VX-3000) so far. I’m able to grab some low resolution frames off it, but can only record about 2 seconds of video before it shuts down. I my try a different webcam as I have a few old ones laying around here.

The powered HUB works great as it is able to power USB devices and the Raspberry Pi – meaning I only need one power adapter.

I’ve also written simple software that allows me to SSH onto the RPi and drive it with a simple terminal program. It works well enough.

Still not there though. I’m currently looking at these challenges:

  • Getting a rechargeable 5V battery to drive the HUB and the RPi. I’ll still power the DC motors from the AA batteries.
  • Make the webcam work better for live video feed. I’ll try replacing the current VX-3000 with a different one.
  • Assemble it! I fear the Mr. Basic platform is too small (see photo) for the amount of stuff I need to put on it. I may be able to make it work, but it won’t be pretty.

L298N

Things are moving slowly but the project is gradually moving ahead.

I have now pretty much completed my “hello world” project of using a Raspberry Pi to monitor a build server and update some LED lights depending on its status. It’s working pretty well.

The next big thing now is to connect the RPi to the motors of the Mr. Basic platform (or any DC motors, really). My original plan was to use the Gertboard for this. But seeing as the Gertboard has yet to be released, I’m going to attempt to do this using the L298N motor controller instead:

The order has been placed. And I’m now just waiting.

In the meantime, I’ll also need to get the wifi adapter working. It looks like the RPi is struggling to provide enough power for it, so I may have to power it using a separate powered USB HUB.

Raspberry Pi has arrived

My first Raspberry Pi arrived in the mail yesterday. I’m very excited.

To get me started, I’ve decided to do a smaller preliminary project on it. It will be quite simple and consist of some minor software development and connecting a few LED lights to it.

I’ve already flashed the SD drive and booted it up using my mobile phone’s charger to see that it actually works, which it does. Next I’ll try to find a separate power adapter for it and then attempt to compile some C++ code on it. I’m curious how difficult it will be to port what I wrote on my PC to the ARM platform.

Mr. Basic has been assembled

I assembled Mr. Basic a couple weeks ago. It took somewhere between 1-2 hours and didn’t require much except a couple small screw drivers.

It’s absolutely tiny and not much to look at. So I’m a bit disappointed. I probably should’ve gone for a higher scale model. But this will do for now.

I tested the motors and they work, which is great. Unfortunately, some of the axels are too tight and the wheels barely turn. I’ll have to adjust this at a later date.

Purchased

Today I made a couple of orders:

  • The Dagu Mr. Basic robot platform from a seller on ebay
  • Several miscellaneous things from dealextreme.com: Soldering equipment, multimeter, a couple servos, etc.

Now the wait begins. The first batch of Raspberry Pis should be ready Feb 20th. And hopefully I will be able to get an order in with the first batch. I don’t know the status on the Gertboards yet.

What to buy?

I’m in the process of putting together a list of hardware to purchase for my project. Until the Raspberry Pi is released (which should be a couple weeks from now), the most important piece of hardware I’ll be acquiring is likely the mobile platform of the rover – i.e. wheels and motors.

Right now it’s between Dagu’s Mr. Basic for around $30:

Or Dagu’s Rover 5 for around $65:

While I’m pretty confident Rover 5 is the better one of the two, this will likely come down to price. And my policy at this stage in the project is “as cheap as possible”.

Electronics Projects for Dummies

Picking this up at the library after work today:

Looking at the contents of it, it should provide me with some much needed reminder of the basics of electronics. Haven’t touched that stuff since university.

Soldering tutorial

This video shows a quick how-to on soldering.

Project site is up

This project site has now been created.

I’ve added a page with links collected so far.