Why Freescale's $2 JM16 might be better than atmel's $10 chip set (+FTDI)


Just reviewing processor specs on Freescale's <$2 JM16 and Atmel's Arduino/FTDO chipset at >$10.
  1. Three Serial Ports (2 com + USB) (full duplex telemetry plus GPS) vs. 1 com/USB on Atmel.
  2. 12 bit ADC vs Atmel's 10 bit. (4 times better resolution).
  3. Included USB (faster everything, more reliable, and save $ on FTDI)
  4. Matrix divider (Both have fast multiply, but Freescale includes Fast divider as well)
  5. Freescale runs at 48Mhz vs 20 Mhz
  6. Both have 6 PWM
  7. USB bootloaders vs. Serial Botloader
My question is have I overlooked some awesome flaw or feature which would undermine the general conclusion that the Freescale is twice the processor (or better) at 1/5 the price? Is it not thrice the com ports, 4 times the ADC resolution, twice the speed, (up to twice the program space on its larger brother jm60 with 60Kb Flash), infinitely more USB ports for much less cost, complexity, points of failure, board space, and weight than a 2-chip solution with half duplex compromises?

So the bigger question is really to the heart of Open Hardware and Arduino - is it worth paying 5 times the price for weak hardware, and a weak IDE just because some components of the tool chain are more open than Freescale's free IDE (which is arguably less "light" than then infinitely light Arduino IDE). Is the Atmel's proprietary chip really "Open Source" if one tool chain component is "open Source" - and is the premium worth it. I have lots of Arduino's and I like them, but I can't help feeling they are a closeted serial device in a USB world, and overpriced (a Freescale Arduino-Clone would probably cost $6 vs. Arduino's $32 because the USB is built-in.)

Just Saying...

Views: 1657

Comment by Michael Zaffuto on May 4, 2010 at 2:39pm
The freescale cpu is very old school. It has to run at 48Mhz to get anything done because each machine instruction is 2 to 6 cycles long, other than the clock speed and USB it is mid 1980's technology.

Arduino is about empowering relatively non technical but creative individuals to use modern day digital control to do something useful or interesting in their own field of interest. Thousands of arduino users have effortlessly blinked their first led and from there have gone on to create for themselves and others. When they've pushed the envelope of this level for all it's worth (like Jonathan Livingston Seagull), they're ready for the next level and can move onwards and outwards.

Arduino doesn't feel bad about that, it's glad it has done its job and waits for the next wide eyed and eager person to help.
Comment by Angus Peart on May 4, 2010 at 2:46pm
There is even faster better things out there, for the same cost...

Arduino isn't going to move and they are pretty clear about that. If you listen to their interview on FLOSS Weekly they say this as well as re-iterate that Arduino is aimed primarily at artists.
Comment by Ken on May 4, 2010 at 3:04pm
How does power consumption compare?
Comment by David Ankers on May 4, 2010 at 4:31pm
Arduino is fantastic for what it is, I know loads of people who started micro-controllers with it, then dump the Arduino stuff and went native AVR, next they moved away from 8 bit architectures and on to the Arm range of Micro controllers or maybe the PIC32.

I personally think the Arduino guys have the right idea, it does the perfect job for the people it is aimed at and the easy of programming lowers the barriers of entry for people. You don't learn to drive in a Ferrari for example and it seems ArduPilot guys don;t want more speed as the new Mega is 20% slower than the old ArduPilot.
Comment by Michael Zaffuto on May 4, 2010 at 4:52pm
@Dave - I suspect the ArduPilot guys could define their system to do just about whatever they want it to be. With undoubtably the worlds largest amateur following, we would follow wherever they take this thing, right? With the great minds who have all contributed to all that has been done, they are not going to intentionally shoot themselves in the foot. How is a 16 Mhz Atmega1280 20% slower than a 16 Mhz ATmega328? Just because the ATmega328 could go to 20 Mhz, it was never run that way, also, if you looked a little into the code and saw a minor time consuming issue related with PulseIN, it's been taken care of by the PPM decoder to free up more cpu time. I'll bet, as I don't personally know, that the group has already tested the very computationally efficient DCM and ardupilot code together and have determined that there is still plenty of horsepower left. I think the ArduPilot guys simply don't want what they don't need.
Comment by Pbreed on May 4, 2010 at 5:29pm
Don't disregard the value of having a ready to use free development library like the Arduino.
That is huge. Personally I like the Freescale MCF5213 and the whole coldfire product line.
All of my flying rockets used Coldfires.
(Full disclosure I'm CTO of netburner and we sell MCF5213 Dev kits.)

I also think that some of the new ARM cortex M3 stuff from T!I and ST are cool.
The new Cortex M4 will have floating point built in, so that could be a really cool solution.

3D Robotics
Comment by Chris Anderson on May 4, 2010 at 6:54pm
David, that's not correct. Both the current ArduPilot and ArduPilot Mega run at 16Mhz. We're still only using about 20% of the computing capacity right now, so there's plenty of juice remaining in these chips (once we upgraded to the Atmega328 we no longer had memory shortages). Indeed, we have so much spare capacity that we're running the IMU on the main processor with Mega, rather than giving it a stand-alone 328 (we have offloaded all RC processing to the second 328 on the board, which replaces the Attiny on ArduPilot).

We're very comfortable with the current Arduino roadmap. They'll be supporting 20Mhz natively in the next rev, so we can get a 25% computation power increase with the current hardware if we want it. And the roadmap goes to ARM-based processors in the next generation, which should future proof it. With 150,000 Arduinos out there and growing fast, the benefits of a large, vibrant community outweigh any technical considerations, in our view. At least in this generation, Arduino is clearly the #1 open source embedded computing environment.

3D Robotics
Comment by Chris Anderson on May 4, 2010 at 6:56pm
bGatti: The next rev of Arduino (out in a few months) is based on an Atmel chip that has native USB built in. Bye-bye FTDI and the costs associated with it (we'll be upgrading the basic ArduPilot board to that). So your concerns about Arduino and USB will be addressed by this summer.
Comment by bGatti on May 4, 2010 at 7:12pm
Thanks @Chris, that is welcome news from the trenches. FTDI is a crock - because it doubles system cost, and the user still has to "please select Com port" ? what com port, this laptop I bought in 1999 didn't even come with com ports!@? yeah, well, that USB thingy pretends to be a com port even though its USB, so you have to pick which com port anyway... and it has nothing to do with which port you have plugged it in to...

is by chance 12 bit ADC?
Comment by David Ankers on May 4, 2010 at 7:16pm
We are saying more or less the same thing Michael, thank you for your reply. Like you said above, when people have pushed the envelope they can move onward and upward to other things, I'm sure ArduPilot are very happy with where they are and DCM does all they need as well.

I will say that personally, I out grew Ardunio a while ago and this is why OpenPilot is based on the ARM Cortex M3, it will be interesting to see how advanced OpenPilot gets in the same time that ArduPilot has taken. Why? It is much harder for OpenPilot to get developers at the skill level required for the ARM microcontroller. Where as Ardunio is designed to have a low barrier to entry, the ARM needs developers of a higher calibre and these uber coders are harder to find.


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