Augusto

From a previous thread where the differences between gyros was discussed I posted that the main difference between gyros is SOFTWARE and not hardware. A moderator argued that his Pentium PC was more powerful than a 386 and that it was that and not software that made the difference between the computers and for some out of the blue reason that analogy applied to gyros.

Today I was repairing my 601's screen and I decided to open the 401 too and take the chance to take a few pictures of the hardware of both units. After reviewing the specs on the hardware I was surprised to find out that not only the hardware is similar but they are identical microprocessors where actually the 401 has the potentially more capable version of it.




The two gyros side to side. Right side is the 601 and left side is the 401.




The 601 uses a Hitachi H8 series microprocessor. This unit has 16k-byte ROM (space for the software) and 512-byte RAM (space for variables and data).

This is a masked ROM version which means the software is burned at the Hitachi factory for Futaba making it cheaper than the PROM version so them being pre-programmed for Futaba Hitachi can also place a Futaba Logo on the chip.

601
HD6433292C98F
5-V Version (16 MHz)
HD6433292(***)F 64-pin QFP (FP-64A)
where C98 is the software version in ROM for the Masked Rom version of the microprocessor.
16k-byte ROM; 512-byte RAM




The 401 uses the exact same series of Hitachi H8 series microprocessors. But oddly enough the 3294 version used in this unit has 32k-byte ROM (space for the software) and 1024-byte RAM (1k) (space for program variables and data).

This version is a one-time programable ROM version so it's programmed at the gyro's assembly time by Futaba (PROM version) so being an IC that can be programmed by any manufacturer Hitachi doesn't place a specific Futaba logo on it.

401
HD6473294TF16
5-V Version (16 MHz)
Package 80-pin TQFP (TFP-80C)
PROM version
H8/3294: 32k-byte ROM; 1k-byte RAM

For more technical info click here.




Even though both microprocessors are capable of 16MHz they are both run at 8.0Mhz. There is no need for more speed. Also less speed means less battery consumption.





Both units use the EXACT same sensor manufactured by Silicon Sensing.


This is the CRS4-SGH01 sensor by Silicon Sensing.





The only significant difference in hardware between them is the extra screen and push-buttons.



The 401 has a potentially more powerful microprocessor than the 601 only because it has more space for programming but it's not used.

Both units have the capability to run at double the speed that they're run but there is no need for that because in both cases the microprocessors are an overkill for the application.

The Silicon MicroMachined Sensor (SMM Sensor) is the same in both units.

This shows that using today's hardware technology what matters in a gyro is the SOFTWARE not the hardware.


Augusto..

Galifrey

WOW I am seriously impressed...

Thats what I call research...

I guess thats why some properly coded programs run faster than other programs with shoddy coding on the same CPU...

Will B

Very interesting stuff Augusto.

Augusto

The question now is what microprocessor and Sensor does the even cheaper GY-240 has.
I wouldn't be surprised if it was the same as the 401.
Anyone cares to open a 240 and let us know?

Augusto.

Galifrey

now that would be scary....

RcFLYBOY24

My Feedback: (5)

so is there actually any advantage the 601 has over the 401? the difference between the two including the digital servos is approx. $180. You could just about purchase two 401's w/ servos for the price of a single 601. the 601 is more than twice the weight as well. as far as i am concerned, the 401 exceeds my needs in a gyro so who would actually 'need' the 601?

Augusto

That's actually a difficult question to answer. If you're a fast learner and you are able to advance to a point where you would need it in a short period of time then I would say get the 601 otherwise a 401 will do.

It's like the radios. It's better to get a radio that has the most features possible at the begining so you don't end up having to buy a new one after a short while.

In my opinion the 401 is a bad mix of something not too good as a 3D gyro and not too good as an FAI gyro but for most people it's a more than sufficient way to hold the tail in place.


Augusto.

mongo

My Feedback: (15)

user adjustable software is the only possible advantage. i do doubt that 180 is a fair value for that option, in most folks eyes<G>

Augusto

From some messages I've gotten it looks like people are getting the wrong message here.

There is a HUGE difference between the performance of those two gyros.

But the difference is due to the different SOFTWARE running on the same processors.

The point of the post might have been taken the wrong way.

What I wanted to say is that that huge difference in how the Gyros work is due to software and not hardware.

It kind of pisses me off that the performance of the 401 having what is for all intents and purposes the exact same hardware sucks (in my opinon) compared to the 601's performance.

Like mongo said the only difference in having that extra screen and push-buttons is the ability to punch the settings instead of turning some potentiometers.

We are paying for software and not hardware. I guess the guys at Futaba took some lessons from Bill Gates hehehe

Augusto.

Furyflyer2

My Feedback: (117)

OH, so what makes the GY-601 have a super narrow pulse (760us) ? Is that hardware or the software that makes it so narrow? Does the gyro your comparing both have a 12 bit A/D converter? Just wondering don't flame me please. Great presentation BTW that must have taken hours, good job.

Augusto

Paul,

Yes the 760us supernarrow pulse is software based and it's programmable to whatever period you chose with the limitation of it being a certain integer multiple of the uP clock. In this case it's equivalent to 6080 clock pulses.

Regarding the ADC. If you take a look at the comparison table you can see that at the "A/D converter" row both the 3292 and the 3294 versions have 10 bit A/D converters with 8 channels. I don't think for this application there's a need for a 12 bit converter. I could be wrong because I haven't done an analysis of the requirements but seems like Futaba decided 10 bit was plenty for the application.

Also in that table you see they have the TIMER feature which is the feature used to create pulses of different widths by software.

The analysis didn't take hours I have most of that info available in my browser's bookmarks from my work.

Augusto.

Hitch-Hiker

Thanks again Augusto for taking the time to share that info with us!

I agree that the 601 is a far superior gyro than that of the 401 for whatever reason. I just know that after I bought my first 601, I was selling my 401's even in the 50 sized machines.

As far as the price diffrence being a reasonable value, I would surely rather visit my LHS to buy one, rather than venture to the garage to try to make one myself . It is really amazing that there are companys making those type of products that better our entire hobby!

Thanks Augusto!
Thanks Futaba!

gjestico

My Feedback: (2)

Excellent info, Augusto. Glad to see you around here.