Newbie questions on Parallax's proto board and proto USB board

unebonnevie

Hi,

I have been reading about Parallax's Propeller CPU and what it can do. Newbie questions:

1. Parallax's proto board has a 5MHz crystal. I want the CPU to go faster. Is there documentation on what the max MHz I can use and what power supply I need to give with respect to the MHz? Right now 5HMz is happy with 3 AAA batteries?

2. The proto board comes with 64KB EEPROM. How high can I go in size for the EEPROM for the proto board? And Parallax sells the EEPROMs?

3. Is there an SD add-on for the proto board (either the USB or non-USB one)? I am looking to interface with a 2GB SD card both read and write.

thanks

Timmoore

1. the prop is spec for a crystal up to 8MHz, but you have enable a pll of x8 and 16. Most common usage is a crystal of 5Mhz and a 16x pll
2. You can get larger eeprom, through the proto board has the eeprom soldered to the board but you can add a 2nd (or more) eeprom, the eeprom has address pins, that change the address it responds to so you can add a 2nd 64K but have it respond to addresses 64K+1 - 128K. I dont remember if parallax sell them but someone like mouser.com do.
3. Yes, there are a number of people who do, look at ucontroller.com, sparkfun.com, futurlec.com they all sell sd interfaces that will work with the prop (they are not usb interfaces but spi interfaces)

Oldbitcollector (Jeff)

Welcome to the Propeller!

You will want to check out the links in my .sig (below) if you haven't already..

Also, here is a Wiki page on speed/oscillators propeller.wikispaces.com/Oscillator

OBC

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New to the Propeller?

Getting started with a Propeller Protoboard?
Check out: Introduction to the Proboard & Propeller Cookbook 1.4
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

Spork Frog

Also...

1. The Prop is spec'd out to run up to 80mhz, but people have ran it up to 100mhz without problem in most situations. I'm not really sure about the largest crystal but I know for sure that at least up to 10mhz crystals work. See the datasheet for more info on all that.

2. Parallax has a small selection of EEPROMs as well, but the only one they sell that will work with the Prop is the 32k EEPROM. Part numbers 2C256, 2C512, and 2C1024 can all be used; check your favorite distributor.

3. The only real difference between the USB Protoboard and the Non-USB Probotoboard is the programming port; all other parts AFAIK are the same.

Mike Green

The EEPROM is soldered onto the Protoboard. It's possible to unsolder it and solder on a new one, but I wouldn't recommend doing that without some experience soldering surface mount parts.

It's possible to run the Protoboard off 3 AAA batteries, but I wouldn't recommend it. It's designed to be used with a battery or AC adapter source of 6-9V. There's a low drop-out 5V regulator to power any 5V logic you might want to use followed by a low drop-out 3.3V regulator to power the Propeller and EEPROM. The power input goes to the 5V regulator which won't regulate at 4.5V. Also, AAA batteries have little capacity and the regulators will draw a significant current as well as the power-on LED. If you want to run the Propeller off a low power source, you'll want to use a very low drop-out 3.3V regulator with a low idle current and substitute that for the Protoboard's on-board regulators. The Propeller's current drain is proportional to its clock frequency and the number of cogs in use. The datasheet for the Propeller has lots of information on current drain and you should look at that.

unebonnevie

Thanks, all for the great answers...I will do more digging, but, at least, looks like things are possible wrt questions and answers.