axon II - is it worth it?

[dellagd]

ok, first of all, I am in no way insulting the axon II. I think its great. but at about 4x the amount of money as an arduino, is it really worth it from a money standpoint? It is obvious that the axon II is superior to the arduino, but the question still stands, is it really worth it?

[madsci1016]

Short answer: depends on the application. 

Arduinos are good for fancy labcoats:

http://www.billporter.info/?cat=5

Axon's are better for advanced GPS assisted rovers:

http://www.billporter.info/?p=95

[Webbot]

I think the question should be "worth what" rather than "worth it"

Most 'duinos are built on 16k program memory boards - maybe 32k with latest boards. The Axon I/Axon II has 64k.
The Axon series have far more I/O pins than most 'duinos.
If you want to add servos etc then you don't need to buy those 'duino shields - just so you can connect something - you just plug it in and it works.

So I would swap the question. Why would anyone buy a 'duino board?
I have run into this particularly with my Project Designer where I need to publish boards showing what headers are wired to what pins. The Roboduino is maybe the only 'duino board that shows this and I would be happy to add others. I have tried to do so - but no-one knows how they work!!!! The others just say this is 'Pin 4' - but give no idea as to what port/pin on the controller  is actually used - obviously a 'best kept' duino secret. No schematics / no info - just dust. I loathe these boards with a complete vengeance as they pretend to be good for newbs but actually give you no information at all.

The Axon is completely up front. You get schematics - the lot. And you can post questions to the designer (who is busy but WILL respond).

"Yes - but the 'duino has a lot of software support." Well if you want Basic then just go with it - "Basic is what Basic gets" - Forrest Gump.

Won't diss their C support - its just an alternative to others including mine: WebbotLib. All I would say is that WebbotLib supports all sorts of other non-duino boards with the same code.

You pay - you live with it

[madsci1016]

but give no idea as to what port/pin on the controller  is actually used - obviously a 'best kept' duino secret. No schematics / no info - just dust.

Actually,



http://www.arduino.cc/en/Hacking/PinMapping168

It's on their reference page.

But, To add the same functionality the Axon already has (like webbot was saying), requires rather overpriced shields, which increase the price.

[Admin]

note: I'm incredibly biased and financially motivated in the following comments . . .

but at about 4x the amount of money as an arduino, is it really worth it from a money standpoint?

The price of an Arduino is a bit misleading. First, you need to buy *two* batteries to run an Arduino - a 7.2V, and another for servos. Second, you need to buy a wiring kit and/or shields to plug stuff in. If you look up the components used on the Arduino, you'll see they are el-cheapo chips, especially the voltage regulator. They lack features/quality to keep the cost down.

Is it ok to pay 4x to get 4x the features?
(I'd argue its like paying 3x to get 5x the features, but again, I'm biased!)


Oh and madsci1016, Webbot was referring to the poor Arduino/imitation board mask labeling (you'd have to manually follow the traces to determine what plugs into which pin of the ATmega).

[madsci1016]

Oh and madsci1016, Webbot was referring to the poor Arduino/imitation board mask labeling (you'd have to manually follow the traces to determine what plugs into which pin of the ATmega).

No, I'm pretty sure he meant what port/pin on the atmega maps to what 'arduino' pin when he said:

The others just say this is 'Pin 4' - but give no idea as to what port/pin on the controller  is actually used -

I guess that what you also kinda said with "what plugs into which pin of the ATmega", which is also answered in my previous post.

I have only used sparkfun fab'd arduinos, and their masking has always been clear:



I think both are good MicroControllers, however both have their place. Hell, my SAGAR robot has both. The arduino runs the motors, tracks the wheel encoders and maintains a commanded speed in cm/s for each wheel; and reports back battery information along with distance traveled to the Axon, which handles all the sensors, GPS and the 'higher thinking'.

The only 'comparable' arduino to the Axon in terms of I/O and memory is the Arduino Mega, which is $65, plus another $20 for a servo shield, and you are pretty darn close the the price of an Axon 1 with a larger foot print.

Also, In my opinion, the Arduino's have a better USB <-> Uart chip (FDTI) than the Axon. (sorry Admin) And I have heard this from other SoR members. The FDTI has more features, including being able to be used as a bit-bang AVR programmer. Hell, if the Axon 3 switched to using a FDTI chip, you could market that it has a built in back up hardware programmer if the bootloader gets corrupted.

[Admin]

Also, In my opinion, the Arduino's have a better USB <-> Uart chip (FDTI) than the Axon. (sorry Admin) And I have heard this from other SoR members. The FDTI has more features, including being able to be used as a bit-bang AVR programmer. Hell, if the Axon 3 switched to using a FDTI chip, you could market that it has a built in back up hardware programmer if the bootloader gets corrupted.

Amusingly, the Arduino above doesn't even have a USB! But I guess that makes it cheaper

The CP2102 has quite a lot of features too. See Software Downloads on the right:
http://www.silabs.com/products/interface/usbtouart/Pages/default.aspx

The FDTI is 3x bigger than the CP2102 - important when I'm cramming every feature I could into the Axon. The Axon, despite all the additional features, is actually smaller than an Arduino

That said, I didn't break out most of the CP2102 pins simply because the Axon itself can do it all but better.

[madsci1016]

Your'e right, i linked a pro, which requires an external USB <-> Uart board to program. However, i linked the picture just to show decent silk screening, not to show that it had didn't have usb.

And thats another thing, in my opinion, i like about the arduinos, is the pro models offload he USB <-> uart to another board. If you did that with an Axon, you would have more room to break the AVR pins out, as well as not limit available hardware Uarts (for uses other then USB) to 3.

I know the startup fab costs are a show stopper for limited run, but it would be nice to have an Axon 2 Pro!

And i might be biased about the Uart chips as well, seeing as a CP2102 mysteriously failed, while i have had no problems with the many FDTI I have.

[Webbot]

Yep - seen lots of these ATMega168 'duino designs.

So they seem to have Pin 0..... = PD0 ......
All understood.

But the ATmega 168 is now effectively obsolete/dead.

Ok I could replace it with DIP replacements 328 etc (but they probably don't have long to go either!)

So lets say I wanted to use an ATMega2561 in a TQFP package or a 2560 or 640 - none in the DIP package.

Then in 'duino language what does, say, pin 8 refer to?

Not trying to be annoying. Just keen to learn as I dont understand how a 'duino digital pin number maps to a given port and pin on any current/future microcontroller!

[Razor Concepts]

We should just stop using 8-bit avrs when there are plenty of cheap ARM devices instead     Someone just needs to make an ARMduino and it will take off!

[Asellith]

First off Axon just has a cooler name. I've heard about 12 different pronunciations of Arduino to top it all off.

maybe its because I was never really a noobie but more of a super noob when I started... I never understood the concept of Arduinos and didn't bother. Having MCU programming experience already I felt way more comfortable dropping my own AVR into a design. I broke down and bought an Axon and well after my experience with the dynamic due of Axon/Webbotlib I never want to look back. My hope is that the Axon/Webbotlib combo plus the OSCAR system (if it ever gets anywhere curse my horrible programming skills) I think offers and open source and affective noob solution that, while its geared more towards robotics then the Arduino system, it has more uses and can be VERY powerful.

Keep up the good work on both the axon designs and webbotlib. hopefully soon I'll get to play with an axon II hint hint VOTE FOR ME!!! Also dellagd this is the reason Admin does stuff like contests. They allow people who can't normally afford AxonIIs to have a way of getting them. Also increases the tutorial count and usefulness of the site.

Ok I'm rambling now time for bed. Stupid late night testing at work.....

[Webbot]

but give no idea as to what port/pin on the controller  is actually used - obviously a 'best kept' duino secret. No schematics / no info - just dust.

Actually,



http://www.arduino.cc/en/Hacking/PinMapping168

It's on their reference page.

But, To add the same functionality the Axon already has (like webbot was saying), requires rather overpriced shields, which increase the price.

Thanks for that. Answers some questions re DIP28. They count pins clockwise . Not alphabetical as it goes D then B, But opens more:-
1. Can it only cope wth 28 pin dip
2. What are digital/analog pins for say an ATMega32 dip 40 or ATmega261 TQFP or ATMega640 TQFP.

Is there a general rule for any processor/package => magical 'duino digital pin number?

[Razor Concepts]

but give no idea as to what port/pin on the controller  is actually used - obviously a 'best kept' duino secret. No schematics / no info - just dust.

Actually,



http://www.arduino.cc/en/Hacking/PinMapping168

It's on their reference page.

But, To add the same functionality the Axon already has (like webbot was saying), requires rather overpriced shields, which increase the price.

Thanks for that. Answers some questions re DIP28. They count pins clockwise . Not alphabetical as it goes D then B, But opens more:-
1. Can it only cope wth 28 pin dip
2. What are digital/analog pins for say an ATMega32 dip 40 or ATmega261 TQFP or ATMega640 TQFP.

Is there a general rule for any processor/package => magical 'duino digital pin number?

Arduino can do the SMD versions as well (I have seeeduino which has smd)

There is no conversion thing, I think its just whatever they decide  


Works good enough if you only are using arduino, but I am using arduino with "normal" style commands so I have to keep a lookup chart like that printed and always handy.... its actually sitting right in front of me

[hopslink]

Thanks for that. Answers some questions re DIP28. They count pins clockwise . Not alphabetical as it goes D then B, But opens more:-
1. Can it only cope wth 28 pin dip

The internal mapping, PORTB 1 to Arduino pin X etc, should hold for the PDIP and TQFP versions of the ATMega168 and '328 (the bulk of the current boards).
 

2. What are digital/analog pins for say an ATMega32 dip 40 or ATmega261 TQFP or ATMega640 TQFP.

Currently none of these are used for an Arduino AFAIK. The only other processor currently used is the ATMega1280 TQFP, see below for pinout (sorry, it's fairly hefty). This should hold for the '2560 if they move up to that.

Is there a general rule for any processor/package => magical 'duino digital pin number?

Like Razor Concepts above I don't think there is any stated convention.




[/quote]

[Webbot]

Thanks Hopslink

That is actually a great example.

A picture of a board with lots of header pins

Lots of info re Arduino pin X goes to processor pin Y.

But its anyones guess as to what all those header pins are and what they connect to. How on earth do users make sense of it?

With a magnifying glass I may be able to work out the silk screen.

But your contribution is far more educational than most. In fact with a bit more info, and a better picture, I could almost add it to Project Designer for use in WebbotLib.

Eg what about all those other headers. eg the 7 above the 'analog bank' - seem to be various power thingies - are they battery, gnd, or regulated 5v, or regulated 3.3v. Cant tell.
The 'digital' pins at the bottom of the board have 2 lots of header pins. Is the signal on the inside row? What are the outside lot? Gnd, power (batt or 5v) ?

What are those big connectors. Look like a battery supply and a USB port. What uart# is this connected to? Various UARTs are listed in the 'comunication' block - perhaps its one of these?

This is the usual problem. Even if I get sent schematics. A schematics just says things like JP2 = pins. But where are they on the board. Or I get board pictures showing pins with no explanatiion as to what they all are.

Luckily the Axon II has been a breeze. http://www.societyofrobots.com/axon2/axon2_datasheet.shtml tells me all I need to know.
I know what header pins are connected to what supply (regulated or non regulated) . If they are signals then what mcu pin they connect to. Simple. Complete and informative. And nothing I can take any credit for!

@Hopslink - please don't take any of this personally - its not aimed at you. Its my usual battle with 'duino boards. They never have a simple image with all the info on.

[hopslink]

Relax Webbot, i'm far thicker skinned than that. As you say it is not my microcontroller board design and documentation, and not my picture either.

If it would be of use to you I can get the information you want put together.

[Webbot]

If anyone out there uses one, and Hopslink or they, can provide the info then I'm happy to add the board so it can be used in WebbotLib Project Designer.

The more WebbotLib'oids the better !

[dellagd]

lol overnight over 15 posts.
so in a short answer, everyone (besides admin, sorry) thinks the Axon II is worth the extra money?
(yest a simple yes and a 1 sentence answer will do)

[Ro-Bot-X]

You need to compare oranges with oranges, so it's Arduino Mega (+ shield) versus Axon II. So the answer is:

Yes.

Do your best for the contest and you might win one!

Edit: Arduino only compares with the $50 robot board, well, some board that is fabbed and sold. But $50 robot is Arduino software compatible. Personally, I like fabbed boards, I've had enough home made boards done when I was young, now I want them to look professional. Roboduino and Romeo are good boards for robotics and so is the board that Circuit Gizmos sells in their $50 robot kit. Pick your choice.

[little-c]

my view is chose the right board for the right job.
for me,

MBED from ARM/NXP for numbercrunching, testing algorithms and test rigs. simply because it has easy to program c comands, well documented libarys, easy to configure i/o pins, usb output to pc, ect... and some major processing power.
   minor bias, i learnt most of my programing on one of these. but they are expensive, so not something to commit to a single project. best used for prototyping, like they where designed for.


cheep pics for small micro projects, or preprocessing sensor output from something like a rangefinder/array of photodiodes. basicly few functions, very little complex code, minimal memory usage ect.

more expensive pics for more complex projects, controling arrays of rangefinders, preprocessing the data, and passing back the data. or simple robots, blah.



an axon would be used for a finished robotic project, ie once the concepts are proved, design finalised ect. and when the robot needs powerful processing. 

personly Im not one for prebuilt boards for a project. build a board for the job. but, prebuilt boards are good for prototyping. or building a robot for fun and stripping it down and adding new functions later.


as a conclusion, an Axon is worth it, if;
 your going to reuse it.
OR
 your robot needs that sort of processing ablity and functionality.

if your just making $50 robot style stuff, its probably not worth spending lots of money on something your not going to use properly.


I kind of want to buy an axon just to see what its like as a board. but cost is one slight drawback. maybe if I can persuade someone its a useful thing for my course....

[dellagd]

uh, I think u guys are missing the question.
is the axon II 3x better than a arduino mega for 3x the money

[KurtEck]

For me; Yes

I wanted the code size, lots of uarts, lots of IO pins, and the ability to directly plug in servos...

I have a BDMicro Mavric board (Atmega) sitting around collecting dust because it was a pain to plug other things in...

So for me, they work great!

Kurt

[madsci1016]

uh, I think u guys are missing the question.
is the axon II 3x better than a arduino mega for 3x the money

3x? The Mega is $65, the Axon 2 is $118.

3x65  != 118.

It's 1.8153846153846153846153846153846x more expensive, but at least 3 times better.

[Ro-Bot-X]

Arduino Mega needs a shield like this one and a bunch of pin headers and some work from your part to make the 3pin headers for servo and sensors directly plug in. That adds about $25 (plus your work) to the $65 the Mega costs, that reduces the difference to an Axon II price significantly.

However, if you want to go cheaper with the Mega, you can find it here for $46.50 and this shield for $11.50. This indeed makes for half the Axon II price, but a lot bigger in size and also needs a lot of work to connect the 3pin headers.

[dellagd]

ok, well seems everyone is in agreement
axon = worth the money
I guess I'll definately be taking the axon II if I win 1st place or be breaking down and just buying it  

[Razor Concepts]

Keep in mind libraries... Arduino has libraries for basically anything you can think of. That is probably the only reason I use it - I don't want to reinvent the wheel. I tried to use a HMC6352 compass using avr studio and some code I found online. Not working, another crazy avr studio error. Then I just copied and pasted a quick arduino sketch, and it worked.

It's kind of like paypal - it sucks in many areas, but so many people use it that you just have to use it as well.

[dellagd]

I took a look at webbot lib and it has functions for anything I might need  (Webbot u owe me  )

[dellagd]

I got the axon II! its all I expected and more