Is the Raspberry Pi 2 best for BrickPi?


#1

The Raspberry Pi 2 is a great advance for most things, but I have to wonder if the sweet spot for BrickPi users isn’t the A+ (due to awesome power management), with the B+ in second place, and the Pi2 a distant 3rd (because it’s power hungry).

The Pi 2 uses even more power than the B+, and what you get for that cost is more memory and faster processing. Unless you are maxed out in at least one of those two ways while running your BrickPi, there is no advantage to switching, and a huge disadvantage, since any autonomous robot will be limited by power storage and consumption.

How many BrickPi users would actually see a measurable benefit from more memory and processor speed?

When I raised the advantage of the A+ for BrickPi use before, I was told that Dexter Industries finds the lack of ethernet on the A+ to be a critical flaw because of all the difficulty with using a wifi dongle.

That issue is real, but I suspect it seems more critical than it is due to a bad batch of wifi dongles. I replaced my original one and the problems disappeared.


#2

This is just a personal opinion but I won’t be using the brick pi much in a mobile robot configuration due to the cost of batteries, I am not sure how long the batteries would last powering everything say with 3 motors and a couple of sensors in it but I don’t imagine it would be long. The way I plan to use it is in projects like the robot arm etc which will allow the mains supply to give most of the juice to the bots, so the benefit of the greater ram and processing speed will definately be an advantage in the setups I plan to run.

For a mobile bot the B+ is definately the way to go though. Haven’t got a wifi dongle yet but will be ordering one soon and am looking into getting some kind of rechargeable battery pack setup to free the brick from its tether.


#3

Why do you say B+ for untethered xuse rather than A+ ? The A+ is almost twice as efficient.


#4

I wouldnt consider buying the A+ simply because it doesnt have an ethernet port and only has 2 usb ports, which would go down to 1 if you had to keep a wifi dongle in it. At some point you are going to need to sit it down and plug in a keyboard and a mouse. A b+ is in my opinion a better option for its flexibility of use and reduced power consuption over the B. I am not saying the A+ is a bad card though, at 20 dollars and a nice small size it definately has its uses.


#5

I would say the A+ has been compromised in many ways so that it will shine in one way, which is untethered use.

It is true you will need a keyboard and mouse sometimes, but not when it is driving around. At that point, power management and efficiency become paramount. There is no getting around the physical limits imposed by battery use (except maybe solar, which introduces other constraints.

The fact that the A+ was introduced when it was is telling us something. The didn’t unveil an obsolete machine. They introduced a specialized machine. Even the short board makes sense in that it frees room for battery and other mechanical bits.


#6

I was hoping I could reply back with something smarter and more informed after I had a Raspberry Pi 2 in my hands, but Newark seems to have flubbed our order.

Indeed, this looks like it’s going to have a pretty big amp draw. I would still side with the B+ being the best option for now, mostly because of that. The B+ just works really well for robotics with it’s low energy usage.

But the Pi2 looks like it has some really awesome features and will really boost the networking and processing capabilities. That’s awesome, especially for stuff like vision analysis and running OpenCV. With the added processing and memory, I hope that makes a huge difference for applicatons.

It’s also probably also awesome for Scratch, since that’s used graphically and can have a bit of a lag sometimes.

As far as battery use goes, we use up a lot of rechargeable batteries around here . . . just a friendly tip. A one time investment in those has saved us a lot of dough!


#7

A quick update: We’ll have a blog post up tomorrow about this.

For now, you can download an updated Raspbian Image here:

http://sourceforge.net/projects/dexterindustriesraspbianflavor/files/