New Toys for Charlie!


SLAM: Simultaneous Localization and Mapping.


I love your hat. My dad was “old Navy” and served all over the place during WWII. We all still call the bathroom, “the head”. :slight_smile:


My great uncle, on my father’s side of the family, served on the cruiser USS Olympia during the Spanish-American War at the battle of Manila Bay.

I did six years in the USN and two tours of Vietnam before I was honorably discharged in late 1973.


I tried to enlist several times during the '70’s. Unfortunately, surgery for a collapsed lung impressed the chief medical officer at Ft. Hamilton so much he eventually 3-F’d me. (I can’t volunteer, but I CAN be drafted!)

I still get a pang of regret when I meet folks like you.

Have a great Veteran’s day!

Jim “JR”


Thank you Sir, much appreciated.

I used my GI Bill to finish my BSEE degree and went on to spend 35 years in the Aerospace Industry as a System/Reliability Engineer to help make the US Military second to none.


If you buy the “original servo package” we will ship you the new one. The shop website hasn’t been edited yet.

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The new Jetson Nano

Admittedly, this isn’t a GoPiGo - at least not yet! - but here is the initial assembly of the new Nano in its new plastic case.

Interesting points of fact in its favor - especially as far as Charlie is concerned:

  1. It uses a Pi camera. Also there are a whole host of “Jetson” cameras with all kinds of unique capabilities that should also fit the Pi. (i.e. Camera with built-in rangefinder, camera with two big IR “headlights”, wide angle, etc. etc. etc.)

  2. It has a 40-pin header on 0.1’ centers that is - by some strange coincidence - set up with the identical pin-out to the Pi. Including the IDENT pins on 21 and 22, and the i2c on pins 3 and 5. (Etc.) This means that - at least in theory - any Pi hat will work on the Nano. More important is that the GoPiGo daughter board should also work. Of course, I haven’t heard of a Raspbian for Robots port to the Nano - or even a plain-vanilla port of Raspbian for that matter! - so anything you, I, or anyone else wants to do will be done “the hard way”.

There are a number of robot kits available for the Nano, all of which use the GPIO. This may be useful as a starting point for interfacing the Nano with Charlie.

Of course, anyone with half the brains God gave a squirrel will know that they (I) can’t come crying to the engineers at Dexter for anything other than the most generic of information about their own hardware. (i.e. What’s the i2c address for the [insert name of interface here].

In it’s current form I’m planning to fuss with it, get to know it, and research ways of upgrading Charlie to use it, if possible.

P.S. If I figure out how, I’ll be sure to let Carl know!


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Thanks, but Carl reminded me that he doesn’t have 5-10 watts to spare in his diet, but will admire Charlie’s power lunching.

Now if you do something with that IMU, on the other hand, Carl is very interested. Carl has been fitted with the nano-watt-sipping IMU and has been playing with it a bit. (Can save and restore a calibration data, and learned that it absolutely must be run in software I2C mode, connected to AD1 or AD2, to properly implement the clock stretching.)

Yea, I see a Ryobi One+ Lithium battery in Charlie’s future if I go that route. Or a small 6v gell-cell.

Not sure how much I can help with the IMU - mine is the Dexter “OEM” version which has native support. One thought is to get the “OEM” IMU, experiment with that and make all the stupid neo/dweeb mistakes first, and then - if needed - graduate to the fancier ones. This is the main reason for my going “OEM” as much as possible. It cancels out most of the silly stuff ahead of time. (i.e. It has native software support, so issues should - mostly - be keyboard-chair interface issues. :wink: )

I already know I’m going to have enough issues trying to fit Charlie with a RTC and a GPS!

Jim “JR”

If I decide that the cross of a GoPiGo and a Nano is reasonably feasible, I may end up having to buy another 'bot to keep the two lines of experimentation separate.

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There is native support for a specific GPS sensor, even within DexterOS. But nothing for an RTC, unfortunately.

Depending on how much of the native Raspbian comes over into Dexter’s re-spins, it may be a cinch since Raspbian has native support for certain i2c based RTC modules. It’s a matter of editing a couple of scripts.

All of Raspbian makes it to Raspbian for Robots. We just add stuff, we don’t remove any.

I have two of the Nvidia Jetson Nanos. I use one as a development sbc with my Lino Robot and the other is presently on a Parallax Arlo chassis loaded up with Donkey Car software.

The Jetson Nano is very power hungry (My Arlo chassis powered by two 12vdc 7 amp-hr SLA batteries in parallel) and I doubt that the GoPiGo3 batteries would last long even if the Nano could be attached in some way to the DI interface board.

You do know that the the Nano GPIO bus is the reverse of the Rpi 3B+ GPIO bus therefore requiring any HAT to be left hanging off the GPIO bus side of the Nano?

I am waiting on the delivery of a Robo HAT MM1 M4 HAT for a Rpi 3B+ that I plan to use on a another chassis running Donkey Car software.


I thought so. In any event I would have to run a ribbon cable to connect them. Maybe flip the connector?

I didn’t know that service level agreements were rated in amp-hours! :wink: That’s a revelation - had I known, I could have made much more money on my service contracts!

So - theoretically - I could spin my own?

If I remember rightly, both the Nano and the Pi use the same processor family, (Arm) - right?

Unfortunately, the Nano’s software is a re-spin of Ubuntu - and as I remember, RFR doesn’t play nice with Ubuntu.

That is correct. The Jetson Nano runs a slightly modified version of Ubuntu Mate. ROS Melodic works well with this version of Ubuntu Mate.


My neumonica must be out of tune, but you lost me with both ROS and SLA in your last couple of messages.

ROS: Robot Operating System

SLA: Sealed Lead Acid (Battery)


If you want to put a Jetson Nano on a GoPiGo3 size chassis, try here.

The GoPiGo3 is way too small to be able to do anything meaningful except to learn to use Python to control a toy chassis.


Whaaaal, I’m not sure I’ll be right willin’ to agree there.

Does the GoPiGo have its limitations? Sure!
Are you going to be able to pull 18-wheelers out of the mud with one? Nope.

However, it’s a pretty darn capable learning platform if you want to cut your teeth on robotics without spending huge amounts of money for the privilege. (The 'bot in your link weighs in at better than $250, especially if you include the Nano itself - and it’s not nearly as cute!)

I have yet to exhaust my ideas for this thing and I am confident that it will keep me busy for a long time to come.

Later - perhaps - I might move to a bigger 'bot, but it probably won’t be better than the GoPiGo. Especially for what I’m doing.