Newbie Q's

jburke71

Greetings All,

I'm having a hard time deciding if the Hydra kit is for me, so I thought I would ask a couple of questions about it.

First off, my main interest is in electronics (I'm pretty knowledgeable as a programmer, but it's the electronic interfacing that I'd like to know better), and I'm wondering about the depth of the electronics material in the book. After reading the hardware section of the book, would it be possible to take the information and develop a separate, simplified console (say with only video, sound and a game controller)? In other words, what's the hacking potential here from an electronics perspective?

Secondly, part of my interest is in learning the propeller chip for robotics control. So, I'm wondering if I would be better off getting the propeller starter kit (even though this looks like great fun. I know my kids would be more interested in this . I'm torn, and I'm wondering if the information in this kit could server double duty for my other interests. I'd love to hear anyone's thoughts on this?

Thanks in advance,

Jason

AndreL

Well, I can tell you that the hydra book comes with very complete descriptions of all the interfaces; video, keyboard, vga, usb, etc. plus there are the nes connectors on the hydra, the expansion port with free card, 128K eeprom, RJ11 phone interface for networking 2-wire experiments. The propeller starter kit is good if you want to learn the propeller and use it to interface to something immediately, but the hydra is more of a platform and has a lot of documentation and software on the system which is more or less a lot of information about how the propeller is interfaced. Plus, the book is of course the only thing that covers programming, graphics, sound, with example after example of everything.

Andre'

Mike Green

The Hydra manual is superb. About 1/2 of it is specific to game construction. The other 1/2 is an excellent introduction to the Propeller, the Spin language, and all the hardware attached to the Propeller on the Hydra board. Truthfully, the Propeller chip is doing most of the work, so there's not a lot of associated hardware, but the manual discusses it in detail.

I would suggest that you get a couple of extra experimenter cards and make some I/O expanders using PCA9554 chips from Philips. These are cheap, readily available from www.digikey.com, and each provides 8 I/O lines that can drive LEDs or be used as inputs. The chip will run from the +3.3V supply, yet can tolerate +5V signals as inputs. You can put two on an experimenter's board to get a total of 16 pins. They'd be wired to the same pins as the EEPROM and there are drivers in the Propeller Object Exchange to access them. The thought is to bring their I/O pins off the experimenters card to a breadboard that you can use to do the robotics control development. When you've got something developed, you can get a Propeller Proto Board and move the hardware and software to it.

One advantage of using the Philips chips is that the expansion port uses the same I/O lines as the VGA output. You may want to use a larger screen for some of your work and the Philips chips won't need the expansion port, just power and the I2C bus connections.

LoopyByteloose

There is an introductory Propeller document - SPIN CODE EXAMPLES - that is tutorial and very simple in nature.

It may be easiest for you to acquire some more generic comfort with SPIN and the Propeller before fully getting into all the aspects of the Hydra [noparse][[/noparse]quite vast as games use everything].

I love the Hydra text as Andre is a goldmine of information, but it is a little like reading 'War and Peace' when some would like to start with Tolstoy's short stories to get a feel for the genre.

Above all, keep an eye out for soon to be published texts on the Propeller chips. Apparently, there are several people working on different introductions and it always helps to get more than one point of view.

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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········

···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

jburke71

Thanks all, the thoughts have been very helpful. Sounds like great fun.

Jason

xtricity

Jason, not sure if you already made your purchase decision or not. However, another great option is to get

The Game Console Starter Kit from Andre's company.
http://www.xgamestation.com/view_product.php?id=32

I have the "Black Art of Video Console Design" and the Pico XGS. The book totally rocks and there's a wealth of info on the CD. If you're familiar with ASM or are pretty down with pointers in C, then you should have a lot of fun. I recommend going to YouTube and watching some videos on soldering techniques if you haven't already mastered soldering. There's also a video of building the pico that I've seen. I also suggest buying third-hand for $6 from an electronics shop. You'll need the SX-Key.

So, the price with a power supply and SX-Key is getting within spitting range of the Hydra and you don't have all the cool 8-core mojo of the Prop and it doesn't help you toward your goal of building robots. So, you might want to go for the Hydra and build the expansion port out with the PCA9554, THEN TELL ME HOW TO DO IT with a nice web page. I think that is beyond my ability right now. Maybe if I stare at the data sheet for the 9554 it will become clear what Master Green is describing. Is this guy a Jedi Master or what? Man, give me some of those brain cells.

Anyway, I'm going to buy the Hydra in the future, but I've been digging into the SX28 and it's a lot of fun. I opted for the Pico XGS because it makes it easier to under the elemental electronic concepts like the D to A resistor ladder, filtering capacitors, 7805 power regulator and function of the heat sink. You'll also get a better understanding of how the chip and the key are powered, and how the I/O works from simple switches or other inputs. The real gem here is the amazing NTSC video desciption. I'm not sure what the Propeller gives you as far as abstraction, but learning about the NTSC video signal from manipulating the timing of the 0-1.5V RCA jack signal is awesome. It's pretty tough going for me, but I view it as a long, enjoyable journey.

Also, since I've improved my soldering techniques, I've been buying parts from Jameco and building a bunch of other things physical. Once you can control the timing of the pin outputs, you can easily control servos or piezo electric speakers. The input stuff from at least the tactile and infrared is straightforward. I know nothing about ultrasonic.

What I want to do now is learn more about the I/O card options for the Hydra. Someone must have broken that out to a breadboard. Maybe the something like this will be available for the Hydra? http://www.xgamestation.com/view_product.php?id=21

Probably get both the Hydra and the PEK. Might be good to get the Hydra first because of the book.

Mike Green

xtricity,
It's so extraordinarily easy to attach a Hydra to a breadboard using the expansion card that it's almost not worth it to do it explicitly. You can even solder a standard 20-pin header to the holes on either an expansion card or memory card and use a one foot 20-pin jumper cable to bring it to your breadboard. You can use short wires to go from the jumper cable socket to the breadboard (just plugging them in) or you can get fancier with the breadboard end of the cable. You need the 8 I/O pins, ground, +5V and +3.3V and can skip the others for most experimenting.

xtricity

Mike, thanks for the response. I thought you were talking about creating some type of port expander using the PCA9554 chip so that the existing I/0 0 through 7, P16-P23 could be used for VGA output. I don't really understand what the PCA9554 does, but it seemed to me to take I/O from some other pins and some software somehow exposed the pins on the PCA9554 as Propeller I/O pins.

Not a big deal since I can probably tap into P0-P7 and just not use the VGA. I was just wondering if there's any way to breadboard the other I/O pins through the expansion port.

AndreL

The hydra expansion port have 8 I/O pins which are shared with VGA, but multiplexed via a buffer, so you don't drive VGA when you are using them. Also, you have access to the networking pins NET_TX, NET_RX, as well as the USB_TX and USB_RX, power, etc. So all in all there are a lot of I/O on the interface, and you simply make little 2 sided .1" spread cards to put your experiments on (or buy them from parallax or nurve) and that's that. So its nice since its sturdy and not all hobbied together with solderless breadboard and connect wires.

Andre'