Tuesday, July 14, 2009

Development Blog moved

This blog has now been moved to the Clearbox Systems Development Blog page. So if you have interest you can continue following it there.

Wednesday, July 8, 2009

USB Design

Today saw the design of the USB circuits for the nControl^2. The goal of the design is to provide 8 USB 2.0 Host ports all capable of providing 500mA power to peripheral devices. To maxamize the bandwidth available to the end devices, I am using 2 High Speed interfaces on the OMAP processor and then using a 4 port USB Hub chip to provide the four powered ports from each of the OMAPs host ports.

The 500mA at 5V required by each port means that in total all 8 ports will require 4A at 5V, or 20W. This will be the major factor in the specification and design of the Power Supply for the nControl^2.

On each of the ports, an common mode EMI filter, has been added to the D-/D+ lines. ESD protection is also added to these lines and Ferrite Beads have been used to try and prevent any EMI issues with the power lines on the ports.

I found on the last nControl project that EMI certification was an issue, and we were only able to achieve FCC Class A certification as there was some intermodulation products from the 25MHz oscillator for the Ethernet PHYs. I am hoping by going to these lengths I will avoid conducted emmissions, and also minimise rediated emmissions to make for an easier certification track down the road.

If anyone has had experience with FCC / CE Certification of USB hubs, I would be keen to hear if there is anything else that I need to look out for on this one.

Monday, July 6, 2009

nControl^2 Development Starts

I have started the development of the nControl^2 (or nControl Squared). The nControl^2 follows on from the nControl which was a small embedded Linux device that was designed specifically to act as a remote monitoring and control node for use with the Newpoint Compass software.

The new nControl^2 will be half the size and square (which is how we came up with the squared name). We have an initial case design following the stylings of the original nControl as shown in the pic to the right.

We are basing this board around the Gumstix Overo CPU module which will give it 600MHz of processing power and 256MB of RAM. It is an ARM core CPU which means it can run Ubuntu (ARM Port) and Windows CE right out of the box. Which should make it easy for people to use.

The initial tech specs that we are shooting for are:
  • 600MHz OMAP 3503 CPU
  • 256MB RAM
  • 1 x 10/100BaseT Ethernet Port
  • 8 x USB 2.0 Host ports
  • 1 x DVI-D video output
  • 1 x USB Debug console port
  • 1 x Mini SD for Filesystem (up to 8GB)
  • Battery backed RTC
  • Power: 9-28VDC, 25W Max (when all USB ports are providing power)
I am hoping that this will be a useful little computing device for many people and would like feedback on any specifications or features that you would like to see in this product. It is expected that we will have the first prototypes ready in approximately 3 months, post comments now if you would like to see any other features included in this development.

Let me know what applications that you would use a product like this for, I am currently expecting the end use to be in areas like:
  • Remote Monitoring & Control
  • Automation
  • Car PC
  • Robotics development
  • Experimantal flight computer (UAV / Hobby)
We will make USB peripherals and drivers available to suit the different markets, for example industrial grade USB serial ports for Automation, and USB GPS for Robotics etc... Also post back to let me know what peripherals would be good to develop.

For reference there are at least 2 other projects based on this same CPU (the OMAP35xx series) and that is the Beagle Board, and the Pandora Console.