Quub is
an open-source, microcontroller system based on a core processor, addressable
daughter boards, and remote IO modules.
The Quub system has the following features.
The core processor board is based on the LPC1549 processor.
Small form factor, nominally
2 x 2 inches (50x50mm).
Addressable daughter boards
can be stacked above or below the core processor.
??-way backplane using stackable headers or a physical
backplane just like the "old days".
The backplane has provision
for I2C, SPI, UART, analogue in and out, and addressing daughter boards..
Up to 16 daughter boards
can be addressed and can therefore share the same system IO lines.
Four I2C channels allowing
for both 5V and 3V3 modules.
Unique module IDs can be read
by the core processor so it knows exactly what IO is connected.
The Quub is a general-purpose embedded microprocessor
system, the form factor can accommodate designs from the simplest
flashing-LED project to a complex multi-processor robot controller.
If you need a system with over 200 analog inputs, or maybe 40+ serial
ports, or more than 500 digital IO connections, no problems, Quub can
do that and more. And if that's not enough hook up multiple Quub stacks
together.
Rationale
Simple systems like Arduino and Picaxe have been around for some time
now while at the other end of the complexity/power spectrum it seems that
a new Linux-based 1GHz ARM board is being release every second day.
All current systems either pay lip service to add-on functions or are
hamstrung by a backplane design that does not allow multiple "shields"
to be used without many clashing issues. The Quub aims to rectify that.
Co-processing — The Quub system is designed to
make the use of co-processors easy. For example the current design for
a 16-servo controller uses an LPC1227 just for this function. At $2 why
not? This totally offloads this time-consuming job from the core processor.
With the prices of fast CPUs falling all the time the use of such distributed
processing is a valid option and it allows a collection of small simple
PCBs to become a very powerful device.
Backplane — With the vast array of I2C and SPI
peripheral IO chips now available it makes sense to have a backplane with
just a few signals that communicates with slave devices using one of these
popular serial interfaces.
The Quub then is designed to rely heavily on these serial communication
methods with the majority of the IO performed by smart peripheral ICs
or dedicated CPUs working as co-processors.
But most systems have these serial interfaces, what's different about
the Quub backplane?
The main difference is that on a Quub system you can address the plugged-in
modules, this means that you can for example have up to 15 identical
modules and there are no pin-clashing issues. Or you can use modules
from different sources and not have to worry about them using the same
pins.
Multi-voltage support. On a Quub system 5V and 3V3 modules can happily
co-exist. The design allows for this from the very beginning, it's not
an afterthought.
Interrupts. The Quub backplane allows up to 60 vectored interrupts
to be provided by modules, that's four per module. So when an event
happens you can deal with it very quickly.
Multi-processing. Special signals allow the programming of up to 16
CPUs while they are in situ, all with a single USB connection.
You want Linux? — While the design of a Linux-based
ARM7 board with HDMI, USB OTG and all the modern goodies is outside the
scope of the current Quub brief, such a board could be designed to plug
into a Quub backplane. That said there a multiple options for a high-end
ARM boards these days and the Quub will not try to compete with them.
The Quub can however be used as an IO sub-system to these more powerful
systems, many of which are somewhat IO challenged.
