Question about whether to buy the Educational Kit or the Hydra Kit

SamMishal

Hi All,

I know nothing about the Propeller chip or the Hydra system and I want to learn about it.

My question is if I buy the Hydra Kit would I be able to use it to do the learning about the
propeller or would I be better off buying the Propeller Educational kit?

I want to get into the Hydra eventually, so I want to save money and buy the Hydra
kit instead of the Educational kit then the Hydra kit.

My concern is that the Hydra may not be suitable for learning about the propeller.
My idea is to buy the hydra and download the education kit's manual and do the
learning using the Hydra kit, then when I know more about the propeller proceed with
the Hydra aspect..... can I do this???

I am new to the propeller not programming or microcontrollers I am experienced in both
aspects and wish to experience the propeller since it seems like a GREAT IDEA and
the multi processor aspect of it intrigues me.

This brings me to my second question.....Am I right in assuming that the Propeller
chip is a multiprocessor chip? Can it do parallel tasking? for example can I have one
Cog monitoring a quadrature system, writing its data to the ram, while another Cog
can be doing PWM control based on data in another area of the RAM and a third Cog
doing coordination of the two????? That would be REVOLUTIONARY·if true.......

Regards


Samuel


Post Edited (SamMishal) : 9/10/2008 11:28:30 AM GMT

SamMishal

Hi again,

Reading through some of the posts I hear talk about Propeller II........

Is this still coming?

When?

should I wait on buying the Hydra till Version II comes out?????



Sam

Mike Green

1) Don't wait for Propeller II. There is no date set for its availability and it's still in the design stages. Enjoy listening in on the discussions and learn something about what's involved. When it eventually is available, you'll have heard some of what went into the design.

2) Yes, the Propeller is a multiprocessing chip. It has 8 essentially identical processors, each of which is quite fast. The 32K of main memory and the I/O pins are shared among the processors.

3) Most of the exercises and tutorials developed for the Propeller Education Kit (PEK) can be used with the Hydra. They need some small changes, specifically the Hydra uses a 10MHz crystal instead of a 5MHz crystal and the timing constants at the beginning of the programs have to be changed accordingly. Also, the Hydra uses specific I/O pins for specific functions while the PEK is wired up as needed. Some PEK tutorials will need I/O pin definitions to be changed, a matter of changing some constant definitions. The Hydra Manual is a very good introduction to Propeller programming, both Spin and Assembly as well as video and graphics generation. I'd recommend buying the Manual and CD even if you get the PEK.

SamMishal

Thanks mike,

I think I am going to buy both any way, BUT I have a question regarding the

PropStick and the 40 DIP versions of the PEK........please read the question

on the other area I posted it (the second posting not the first one)

http://forums.parallax.com/showthread.php?p=750248

I hope you can clarify this for me....



Thanks



Sam




Post Edited (SamMishal) : 9/10/2008 2:45:44 PM GMT

RossH

As a Hydra owner myself, I can only recommend that you DON'T BUY THE HYDRA - at least not unless you want to spend weeks and weeks having inordinate amounts of fun while learning about multiprocessing!

Seriously, I bought the Hydra because it seemed like a well-thought out and well-put together platform for learning about the Propeller chip. Which it certainly is. But it's also a seriously fun games development platform. I'm now spending all my evenings working on a version of "Wing Commander" for the Propeller.

Good luck with your decision - but don't say you weren't warned!

Ross.

Roy Eltham

I have to admit, RossH is correct!

I thought the same thing, but then I got sucked in! I was planning to just learn the propeller chip because I want to use one with my Vex robot stuff. Now I am spending every evening/night working on stuff for it.

Parallel Universe

It depends what you want to do.

If you want to build a project with LEDs, or motors, or sensors or something, go with the education kit.

The HYDRA is a great platform for learning the Propeller and game development. I highly reccomend it.·It (with the SD-Max, which you should also get!) has pretty much all the hardware you could want, but it's a little hard to add functionality due to lack of free·IOs and no easy prototyping.

It just comes down to what you want to do: software of hardware. But if you don't get the HYDRA, you can't play any of the great games on this forum!

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SamMishal

Thank you all for your input,



I have decided I am going to buy the PEK (40 DIP) and the Hydra and I am ordering the SD Max.

But I have a question.... Is it true that With the SD Max there is no need to get the 512K memory module?

Can any one explain to me how the memory map of the Hydra works.... does the SD act as ram

or rom or as a drive....do I need to have the 128K ram (or 512K) at the same time as the SD

or is the SD a replacement for the 128K and since the SD can go up to 2G then there would be no need

for both the 512 and the SD an thus I won't need to buy the 512K since not even the 128 is

needed when one has the SD??????????????



Thanks



Sam

Roy Eltham

You can only plug in one of the addon cards at a time.

A lot of people go with the SD Max, I got the HX512. It's really dependant on what you want to do with it.
You could wait on getting any addons until you've got the thing and played with it a while.

Parallel Universe

Nice choice! You get the best of both worlds.

The Propeller has 32 kilobytes of integrated RAM.
The HYDRA board has a 128 kilobyte EEPROM chip that you can use to store a game. But since the Propeller can only load 32 kiB at a time, the upper 96 kiB· can really only be used for in-game assets like sound and graphics.
The SD Max allows you to store thousands of games. You can write to it, but it's used more as a ROM device. It has a 128 kiB EEPROM on it to hold a bootloader program that reads the games off the SD card and into the Propeller's RAM. (The EEPROM needs to be on the expansion card because inserting an expansion card turns off the EEPROM on the HYDRA board.)
The·XTREME 512 adds 512 kiB of externa·RAM to the Propeller's internal 32 kiB RAM. It also has a 128 kiB EEPROM to replace the EEPROM on the HYDRA board.

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SamMishal

Parallel Universe,

If I understand what you say, the 512KB card would be better than the SD since

it allows the Hydra to have more than 32KB ram....is this so?

So with the 512KB card the hydra would then have access to 512KB

ram instead of just 32K...or does it still have to load 32KB chunks

into the propeller's 32kB ram??

If it is the latter case then why can't it do the same from the SD

why can't the SD act as (slow) ram??



Regards

Sam
·

Parallel Universe

You can do a lot of things in the 32kiB of interal RAM. The external 512 kiB can really help you with large, high color graphics. I don't have the XTREME 512 card, but it should function as an extension to the Propeller's RAM with a comparable read/write speed. Someone who has it can give you better advice.
The SD card is a little too slow for RAM, but you could use it to store large assets. Deep Fry (I think)·built·a SD card video player. The SD Max could also be used for high-volume data-logging.
It just comes down·to what you want to do. If you want a lot of RAM for graphics, go with the 512 card. If you want to store a lot of stuff semi-permanently, go with the SD Max.
I like the SD Max because I can run several different games without having to re-download them to the HYDRA. (Done)·It's also a good way to learn about the file system. (Soon)


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Post Edited (Parallel Universe) : 9/16/2008 2:19:12 AM GMT