Pi 4 or Nvidia Nano?

[jesse brockmann]

If you were building a rover what would you use? And why?   Is there some other option I should consider?

Thanks,

JesseJay

[Steve Okay]

Tenacity is a SAWPPY-alike design with a Pi 4 running ROS talking to an ATMEGA 2560 which runs the motor controllers.

6 motors with encoders take up a LOT of GPIO lines.

Navigation right now is handled with a LIDAR but I've been tinkering on my bench with a Nano and dual Pi cameras for stereo vision.

For the next one, already on the drawing board, I'll probably go with a Nano.

HTH,

-----Steve " 'dillo" Okay

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[Ralph Hipps]

From what I have heard, Nano all the way.

Much better camera processing power, much faster in general.

Support sounds amazing as well.

More $$ but probably worth it.

[Steve Okay]

On Wed, Sep 23, 2020 at 6:30 AM Ralph Hipps <ralph...@gmail.com> wrote:

From what I have heard, Nano all the way.

Much better camera processing power, much faster in general.

Support sounds amazing as well.

More $$ but probably worth it.

Not really more $$. The 8GB Pi4 is $99. The Nano Dev Kit is also $99.

There are lower-end Pis that are cheaper, but honestly, if you're seriously thinking about a Nano, why would you get one ?

'dillo

[Jon Watte]

The CPU is slightly better in the Pi 4. The Pi 4 has built-in WiFi, which I have to add with a USB dongle on the Nano. There is a larger community of hobbyist developers, most of whom are probably less experienced than you are.

There ends the advantages for the Pi 4. The Nano has better camera support circuitry and hardware encoders. The Nano has a much better GPU. The Nano has a very easy time installing reasonably-modern "deep" learning models, and also has sample code for things like visual odometry. And, most importantly, most of the Nano software stack scales up to the Xavier, as well as Mini-ITX systems with full-fledged GPUs. (There are some minor differences between "Jetson" vs "Desktop" platforms, but they're not that big.)

If I were to start another rover today, I'd probably use the Xavier NX. It's the same size as the Nano, but it has a much more modern CPU, with more cores, and more modern GPU, with more cores, as well. (In fact, my current rover has a Xavier on it, but the "full fat" version, that's a bit bigger, and has EVEN MOAR CPU and GPU.) It also supports two CSI cameras. Compared to the cost of all the bits that need to actually go on a rover these days, the additional cost for the NX part over the Nano part is totally worth it IMO.

For the low-level interfacing, I'd almost surely use one of the Teensys. The 4.1 is out, and is awesome. Or, if I still need 5V, and don't want to bother with level translators, the 3.5 is still a solid choice.

Sincerely,

Jon Watte


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"I find that the harder I work, the more luck I seem to have." -- Thomas Jefferson

On Tue, Sep 22, 2020 at 8:53 PM jesse brockmann <jjbr...@gmail.com> wrote:

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[jesse brockmann]

Thanks everyone.  I've actually got a 4gb pi 4 and a nvida nano as well.  I like idea of being able to upgrade to the Xavier NX down the road.   I've done a lot with the pi over the years so it's time to play with the nano.   I'm interested in what I can do with the realsense D435.  :)

JesseJay

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[Steve Okay]

Nvidia has just announced a $60 Jetson Nano. 2GB RAM, 1 camera slot, no WiFi, no M.2 storage and only 1 USB 3 port.

Still has the same 128-core GPU w/ CUDA support though. 

Hackaday has the story:

https://hackaday.com/2020/10/05/nvidia-announces-59-jetson-nano-2gb-a-single-board-computer-with-makers-in-mind/

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[jesse brockmann]

Sparkfun has it for pre order, and I knew that was coming out (being brand ambassador has advantages).   With the limitations it hardly seems worth the cost difference?  I will stick to the 4gb but I'm sure there are projects where it would be a great fit.

JesseJay

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[Jon Watte]

I wonder why they keep pushing downwards in this market.

My personal theory is that they have a bunch of chips they built for the Switch, but didn't quite pass qualification and thus go to a second-level bin. (The Nano only has half the GPU power of the Switch, which is a TX1.)

As a secondary benefit, getting more people into the NVIDIA ecosystem early may inspire a couple of engineers to specify NVIDIA over the competition once they're inside some real development company, but that's a very long run play :-)

Sincerely,

Jon Watte


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