Compatibility (A+ and Mindsensors EV3 adapters)


#1

Hi all,

I’m new to BrickPi. I bought it as a gift for my son and am trying to compile the elements necessary to integrate it with our Mindstorms collection. We have EV3 (and RCX) but no NXT parts. Several questions naturally arise, and collecting the answers will, I hope, result in them being added to the BrickPi info page so others can find them.

Here are the questions I can’t answer:

  1. What ever happened to the firmware beta that was supposed to allow EV3 sensor compatibility? Was an update released? If I just got my BrickPi, does it have EV3 sensor compatible firmware onboard? If not, is the Beta sound enough that I should consider re-flashing it?

  2. The Raspberry Pi A+ seems like a natural match for the BrickPi since it uses so much less power than the B+. (Power Consumption in the A, A+ and B+) It appears that the form factor will work with both Dexter Industries BrickPi enclosures (the A+ is shorter, but has the mounting holes in the same place), and it looks like the pins are in the right place to attach the A+ to the BrickPi. Can the A+ and the BrickPi be used together without tweaking anything? If so, shouldn’t the BrickPi web page proclaim that compatibility proudly? And shouldn’t users be advised that use of the A+ will substantially extend the battery life of untethered BrickPi Bots? If they need tweaking to be made compatible, what kind?

  3. For BrickPi users with firmware incompatible with EV3 sensors, will the EV3 sensor adapters and Multiplexer render the EV3 sensors compatible with BrickPi?


#2

Hey Bret,

I’ll try to answer your questions as best as I can.

1). The firmware and updates are still there. Some of the units we have had manufactured now have this firmware in them, but we don’t guarantee it yet. You can test whether you have the firmware on board or not by running the test program in python.

If you don’t have the EV3 version installed, you can install it using our instructions: http://www.dexterindustries.com/BrickPi/design/brickpi-firmware-update/

2).

Can the A+ and the BrickPi be used together without tweaking anything?

We haven’t had a chance to test mechanical fit. But yes, it looks like it will work because no serious hardware / pin changes have been made.

If so, shouldn’t the BrickPi web page proclaim that compatibility proudly?

If it turns out to be true, yes, we would proclaim it proudly.

And shouldn’t users be advised that use of the A+ will substantially extend the battery life of untethered BrickPi Bots? If they need tweaking to be made compatible, what kind?

Yes, the A+ will perform, power wise, much better. The major drawback of the A/A+ is that it doesn’t have an ethernet port. This is a killer: we think the ethernet port is the easiest way to get setup. Most customers stumble on setup. So we’re not terribly crazy about the A/A+.

3). For BrickPi users with firmware incompatible with EV3 sensors, will the EV3 sensor adapters and Multiplexer render the EV3 sensors compatible with BrickPi?

We haven’t tested or used these products out, and we haven’t seen a lot of folks using these products either. But in theory it should work. It would require some software / firmware writing though by the user.


#3

Excellent answers. Thanks!

It leaves me wondering, though, why you all see the loss of ethernet on the A+ as so very problematic. Is the absence of ethernet really crippling for BrickPi Bot use? Seems like the loss would have to be really awful to negate the power savings of the A+ (almost 50% savings over the B+).

Eben Upton’s thoughts on the design and value of the A+


#4

Bret, if you look through the BrickPi forums, you’ll notice that the most frequently asked questions and complaints are about connecting to the Raspberry Pi. Scarred from all the questions, we’ve tried to make it as easy as possible. In our experience, the easiest way to connect to the Pi is over ethernet, with a pre-cooked Bonjour address.

Eben Upton is a smart guy. The B though has outsold the A by many, many times over (probably powers over). There’s probably a reason I guess.


#5

Ok, thanks.

For what it’s worth, the advantage of ethernet wasn’t obvious to me in looking at the getting started page, or the forum, but I get it now.

Does the ethernet advantage persist if you are using the Pi directly (with keyboard and screen)?

With respect to the B outselling the A for some reason. I take your point, but I think the reason for that is quite clear, and the logic reverses in some applications. The B line is more powerful, and still very cheap–hence the greater popularity where the board is connected to the wall, or to the wall through a larger computer. But the trade-off with computing power is greater electrical power demand, so the priorities reverse for most battery powered, mobile applications. The B+ has more computing power, and uses more juice. For most robotics, the extra memory of the B+ is not valuable, and the greater requirements for electrical power are limiting. Perhaps that wouldn’t be true if the bot was recording video, or taking many still images.

I have a B+. I’m going to get an A+ when they hit $20 and see if I can get it to work well with the BrickPi. I’ll be sure to report back.


#6

The procedure for flashing the firmware to get EV3 working seems to be complex and at 30 dollars plus shipping seems just a bit expensive. I am not thrilled by the prospect of having to buy an entirely different card + a cable/jumper kit to simply flash a chip.

Putting the grumping to one side for a moment, you might consider bundling the Arduino and ISP programmer kit in with the BrickPi starter kit (at a discount) if you can’t verify the boards are flashed to the required state.


#7

Hello Pi-in-the-sky, Thanks for the feedback on our product. You might have misunderstood though; you don’t require an entirely different card; if you want to upgrade your firmware at this time, you indeed need a cable set.

In the near future, we’ll be putting this firmware on the items we ship. You can imagine, I’m sure, that we would want to make sure the firmware worked before we released it on our customers.


#8

Hi there, sorry if I picked the process up incorrectly.

I was under the impression that to flash the firmware I needed to have an Arduino Uno and the cable set to do it?

I had been fiddling with my pis for 12 hours so maybe I got my wires crossed?


#9

If you want to flash the experimental firmware, yes, you need to have an Arduino and cables set. Does that make sense?


#10

Yup, to get the ev3 motors and sensors working thats what needs to be done. I will be ordering the parts after our school gets back from the Christmas break. ATM I am working with our nxt motors and sensors to get them up and running. Once we can prove the set up is nailed down we can go to the school owners with some proof that the brickpi is a good investment with the hope of getting a few more ordered.

It won’t hurt to have an Arduino Uno board in the bag We do already have a newly delivered Arduino Mega, it’s just that over in Indonesia money is tight and every penny is cared for :slight_smile:

Good luck to you guys, I think what your doing here is fantastic and it has given our fledgling robotics programme a real shot in the arm.


#11

Just to be clear: EV3 motors work with every single BrickPi firmware version that we ever shipped. The sensors are just the challenge.

Either way, our next manufacturing run will have the EV3 code on it. We just wanted to be super-sure that we weren’t putting something out there that didn’t perform. Thanks so much for the feedback!