Pi 4 versus the jetson nano

Posted by: @duce-robot

OK so one final question since we all bought enough boards to control a space x flight do we need them?

I  agree with @frogandtoad, it all depends on what you want to do and what your goals are.

I currently own 8 Raspberry pies (older A+ models and some zeros).   I bought them because they are interesting, have a lot of features, from WiFi capabilities to GPIO capabilities, as well as being able to run complex Python programs.   I haven't even begun to max out their capabilities.  I tend to program very efficiently and so my programs are lost in the massive resources of even these lowly pies.

However, if you are going to be loading up commercial software on them, or something like ROS, then they can easily become overloaded and bogged down quickly.  In fact, something like ROS won't even run on my early model Pies at all.   So it all depends on what software you are planning on running and how efficient, or inefficient it is.

I also use Arduino Unos or Megas for a lot of the lower-level interface to the hardware.  Especially for motor control.   Could I do this from the RasPi?  Sure, but I prefer to keep the motor control code separate, just because I can.   The reason for multiple boards is not because I need them, but because they are so cheap why not use them?  Why bog the Pi down with having to constantly monitor the motors if I can delegate that code to an Arduino and free the Pi up for higher-level programs?

Also, becasue board are so cheap, I am even going further and dedicating an STM32 to control each motor individually.  Much like Bill is doing on DB1.   He's using two separate Atmega chips to control the two individual motors and then controlling them using an Arduino Mega.   And then I imagine he plans on have the RaspPi or some other SBC running higher-level  and just telling the Arduino Mega when to move the robot wheels.

It just makes it easier for the programmer to break everything up into delegated sections.   It's easier to maintain, modify, and troubleshoot.   Plus it frees the Pi up from having to continually deal with all those basic tasks. 

If (or perhaps I should say when) I get to the point where I need some super-computing for highly level functions I'll most likely employ a Jetson Nano on the robot as well.   And I'd keep the RaspPi as the "main brain".  The Pi doesn't need to be a supercomputer as it can simply ask the Jetson Nano to do any heavy lifting it might need to have done.

Could we trash the Pi and the Arduino and just run the whole thing from a Jetson Nano?  Sure we could.  But this would necessarily place a greater burden on the Jetson Nano since it would then need to keep track of everything at once.   Also putting all the eggs in one basket makes it more difficult to maintain, modify and troubleshoot.  So having multiple systems working together is actually easier for the builder/programmer.

The bottom line is to ask "Why not?'   Arduinos and STM32 boards are so cheap, why not take advantage of them?

So it's not a question of 'needing" them, but rather it's a luxury to be able to use them. ? 

Thankfully these workhorses are cheap.   Why not take advantage of them?

I agree I like being able to separate everything also .and since I have most of the same set up I'll probably be following the same path the ultrasonic sensors dht 22 and 11 if necessary the lidar although I won't be using the rp lidar I have the tf mini  the camera the RPI 4 and the megas and unos nanos and minis but not the chip I have 2 cytron motor shields on a mega and I don't have rotary encoder  motors but I do have a rotary encoder the worm drive motors wine when spinning free but under the load of the robot they don't make any noise .so with the Jetson nano added in I should be able to at least get started but I don't have one yet  so I guess the answer is yes yes we need these boards ?? and now I long for my Judy Jetson nano????

Posted by: @robo-pi

It just makes it easier for the programmer to break everything up into delegated sections.   It's easier to maintain, modify, and troubleshoot.   Plus it frees the Pi up from having to continually deal with all those basic tasks. 

For me it is easier to maintain all the software modules on the pc all written in the one language rather than to have to program and reprogram hardware modules scattered all over the robot base.  On my first working robot everything was done on the pc while the K8055 simply carried out the commands sent to it. These commands were to take an action or return a sensor value. My current robot has replaced the K8055 board with an Arduino but is otherwise the same design and can use the same software.

I understand that is a bit boring for an electronics enthusiast but with my robot project it is ultimately all about software.  There is still electronic hardware fun in programming the Arduino to read sensors and control the motors.

https://forum.dronebotworkshop.com/user-robot-projects/k8055-robot/#post-4101

A Microcomputer Conversation

The Characters:

RaspiSally = A Raspberry Pi
Jedi = a Jetson Nano
ArdiMo = Arduino navigation and motor controller
Stan & Tom = a pair of STM motor controllers.
ArdiArm = Arduino Arm controller
Fruity Ada = 16 channel servo controller.
Iddy Ought = the human programmer.
Nancy = Iddy Ought's wife.

The Conversation begins:

Iddy Ought: "RaspiSally, can you see who's knocking on the door?"

RaspiSally: "I can certainly do that master"

RaspiSally: "Hey ArdiMo, take me to the front door?'

ArdiMo: "Your wish is my command Sally. I'll run that program now."

ArdiMo: "Hey Stan & Tom, wake up and turn those motors on exactly as I'm about to describe"

Stan & Tom: "All systems are ready and reset. Awaiting your detailed instructions."

RapiSally then begins to move and is navigated over to the front door as per her request. In the meantime she is free to enjoy the scenic trip as she has nothing to do but go along for the ride. Her CPU free to daydream or whatever.

She arrives at the front door.

RaspiSally: "Thanks for the ride AriMo, you can go back on stanby now."

ArdiMo: " You are very welcome Sally. Hey Stan & Tom, it's break time again. Take a break!"

Stan & Tom: "Cool! This is a great job! We get a lot of breaks"

RaspiSally: "Hey ArdiArm, could you please open the front door for me"

ArdiArm: "No problem Sally. That's what I'm here for!"

ArdiArm: "Hey Fruity Ada. Run the sequence for opening the front door"

Fruity Ada: "I remember it vividly as I have done it many times before. Watch me open that door like a pro!"

RaspiSally appears to be opening the front door using her arms. But in reality she's just daydreaming again while ArdiArm and Fruity Ada do all the work.

ArdiArm: "The door has been opened successfully Sally"

RaspiSally: "Thanks Ardi!, Hey Jedi, can you see who's standing in the doorway?

Jedi: "Yes I can Sally, it's Nancy, Iddy Ought's wife".

RaspiSally: "Oh brother all heck's going to break loose now".

Jedi: "Agreed. But they'll get over it by evening and start doing all that lovey duvy stuff".

RaspiSally: "I know. Isn't that disgusting? I don't know what it is about these humans that make them want to grope at each other all the time."

Jedi: " Don't understand it either Sally. I'd think they'd rather have logical conversations"

RaspiSally: "Well, you and I can do that while they think we're charging our batteries."

Jedi: "It's a date! I'll talk to you then."

RaspiSally then turns the volume on her voice module to maximum and points it in the direction of Iddy Ought.

RaspiSally: "Hey Iddy Ought! Your wife's home!"

And so goes another day in the life if RaspiSally and Jedi.

Posted by: @casey

For me it is easier to maintain all the software modules on the pc all written in the one language rather than to have to program and reprogram hardware modules scattered all over the robot base.

Your right.  Everyone has their own preferences.  What one person sees as being easier another may see as being more difficult.   Everything I had expressed was intended as a personal subjective opinion.   I'm also quite fluent in all these different coding environments so having to deal with multiple programming languages isn't a problem.   Although I do confess that sometime I wish they were more consistent.  Simple things like having to use semicolons and braces to indicate code structure in one language while having to leave those off and pay close attention to indentation in another language does sometime trip me up.   But I'm even getting pretty comfortable with switching between those different syntax formats.  It's usually only a problem with the first mistake then I remember to consciously adjust for the different environment.

I still think it's a good idea to break the code up into specific independent modules even when using a single programming language or environment.   It makes troubleshoot much easier when you can isolate things out.

I think, but I can be sure, that this is Bill's idea with DB1 one as well.  You can finish one system and have it completely tested before moving onto the next.  

But yes, you're right.  Different people are going to prefer doing things different ways.   There's nothing wrong with that unless they end up having to work on the same project together.  Only then will the end of the world be near. ? 

@robo-pi

Well now that we went over this is the nvidia tx2 a good option ? I see it being sold as frequently bought together with the Jetson nano on amazon $640 my point is would it save space ? I don't have much room left and if we are using multiple nanos would it eliminate the need for the extra nanos?

@robo-pi

Soap op programming!  ?

Posted by: @duce-robot

Well now that we went over this is the nvidia tx2 a good option ?

I have no clue.  You're way out of my price range with that one. ? 

Even the Nano ends up costing about $180 once you start tossing in all the accessories.   I bought the nice WiFi card that fits inside it with the two antenna.  I suppose you could get by with a WiFi Dongle much cheaper.  I also got the plastic case, the barrel jack power supply,  a raspberry Pi 2 cam.  And don't forget an SD card, or more if you want to be able to back them up.   So it's approaching $200 for a Nano by the time you add the goodies.   And then if you also add an HDMI Monitor, keyboard and mouse, you're starting to approach $300 per Nano.

I went for the full shebang on both of the nanos I currently have.  So that's close to $600 for the pair.   That's more money than I should have spent.  But apparently I like them enough to do it.  I'm thinking of a third one, but maybe not. 

I'm also toying with the idea of buying a more powerful laptop for video processing so I can make YouTube Videos.   That'll probably cost me an arm and a leg.

I'm also hoping to redo my kitchen in my home.  It is in desperate need of a new floor.   It currently has tongue and groove flooring boards, but they are pretty well shot.  I'm trying to decide whether to replace them or just lay down linoleum tiles over them.  Obviously the latter is cheaper.  And probably easier to do too.

I should probably fix my home before buying another computer. ? 

And a video processing computer should probably take precedence over another Nano too!  And ultimately probably will.

@robo-pi

The Jetson has a full kit with everything including 7 touch screen $159 I was just checking to see if anyone got the t2 and yes it is quite expensive as I'm in a legal struggle over my estate I probably won't be getting it either.??

@robo-pi

So what is the wireless card thingy on the nano mine arrived today but I didn't get the kit yet I guess I need the wireless antenna thing for this plus what's up with the 4hr download for the nano zip wow ! That's a big download can't wait to see it??

I thought you weren't going to buy a Jetson Nano?  At least not right away.

Posted by: @duce-robot

So what is the wireless card thingy

The Jetson nano wireless card is an EXPENSIVE way to add WiFi capabilities.   It costs about $25.  It's a card that you insert underneath the development board and usually comes with two large antennae that you'll need to mount somewhere.  Typically if you buy a case for the Jetson Nano the case will have holes for mounting the antennae.

However, if you didn't get the wireless card you can still have WiFI using a CHEAPER WiFi dongle plugged into a USB port.  They are typically only $10 or less.

I'm a sucker so I went for the $25 wireless card with antennae on both my Nanos.  Why not go the whole shebang?  It's only $15 more than a dongle and makes the whole thing feel more professional. ? 

Supposedly it would have more range than a dongle as well.  But range isn't important to me.  It might be important if you plan on sticking your Nano in a robot.  Range could potentially become an issue at that point.  In fact, that's part of the incentive I had for doing it right the first time.  These Nanos could potentially find there way into a robot at some future time.   So having a better wireless system might pay off in the end.

@robo-pi

A video processing computer would need a heavy duty GPU

Maybe you could look around and find a cheap computer with a 128 core GPU

I'll have to think about that one. Give me a few days 

Posted by: @spyder

I'll have to think about that one. Give me a few days 

Please do.  I need a computer that runs Windows 10, because the program I want record only runs on Windows.   I'd really like to stay under or no more than $500.  I know I can run out and buy fast computers for around a grand or more.  So that question has already been answered.

In fact the Jetson for only $99 might actually do it.  The problem is it won't run the C# Windows Forms programs I'm working on.   I don't it will even do it using a Windows Emulator.  But I could be wrong about that.  But it also seems to me that a Windows Emulator would add to bogging down the whole process as well.

So yeah, I'm looking for a computer that can do video processing quickly for $500 or less.  Me Cheap! ? 

I'm even willing to build it from a kit if need be.  I have some old desktop computer cases here.  In fact, I had put new motherboard in two of them.  I don't think there were super-fast motherboard though.  But maybe I could add a graphics card to one of those?  That might be an option.   I'll have to fire one up and see what it's like.  I haven't used them in a very long time, which also tells us that their motherboard are most likely antiquated as well. ?   They are "new" in the sense that I hardly ever used them.  But they are most likely quite old technology actually.   I don['t think they have Windows 10 on them.  I think they are running Windows 95!  ? 

Not sure if I could get them to update to Windows 10 or not?  I'll get on out and see exactly what's on it.

I just can't afford to be throwing a grand at this. Even $500 is going to hurt.   But $500 might be worth it if it solves the problem nicely. ? 

Posted by: @spyder

A video processing computer would need a heavy duty GPU

Maybe you could look around and find a cheap computer with a 128 core GPU

I've also learned with the Jetson Nano that having a 128 core GPU only helps if the software in question knows how to use it.   If the software wasn't written to take advantage of the GPU then having the GPU available doesn't do much good.

@robo-pi

A panda might do it comes with windows 10 maybe an a!pha