beginner's question

lostsouldark

Hello,

I'm a beginner with basic stamp and robotic.
I would know how many sensors can we put on the sumo board, and hwo on the board of education ?
sensors like PIR, LCD, digital thermometer ds1620, photoresistor.

Thanks a lot,

lostsouldark

Bruce Bates

lostsouldark -

Your question seems to contain a limitation which really doesn't exist, so if I may, let me re-phrase your question as follows:

Does either the SumoBot programming board, or the BOE programming board present any limitation as to how many I/O pin ports are available for use by the programmer?

The answer to that questions is - no, not as far as I am aware. The basic limitation of the number of I/O pin ports available for use by the programmer is based on the underlying PBASIC Stamp. Parallax thoughtfully publishes a Stamp comparison document, which you will find attached to this message. Therein you will find each of the PBASIC Stamps, and how many I/O ports each has. There is a good deal more information than that, all summarized on one page for ease of reference.

There is a circumvention to even this limitation, and that's through the use of shift registers to (artificially) increase the number of input or output pin ports. There is a Nuts and Volts article which addresses this very issue, and shows how to use them. There is a TON of information contained in the Nuts and Volts columns, which can be found here on the Parallax web site, and they are free for the download:
http://www.parallax.com/Resources/NutsVoltsColumns/tabid/272/Default.aspx

Volume 5 Column 109 contains the applications information for expanding the PBASIC Stamps' I/O ports by use of shift registers.

I hope that answers your question and doesn't confuse you.

Regards,

Bruce Bates

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When all else fails, try inserting a new battery.

lostsouldark

thanks a lot for this response so precise and complete.
if I have understand all of that (I hope, my english is not as well as I would), I could put all of these sensors for example (PIR, LCD, digital thermometer ds1620, photoresistor), if I have the good processor ?

thanks again, I'll read Nuts and Volts with interest

regards,

lostsouldark

Bruce Bates

lostsouldark -

I'm not sure I'd use thwe word "good processor" as to my minnd ALL PBASIC Stamps are good processors

Here is a brief run down:

BS1 Stamp - 8-I/O pin ports

All BS-2 Stamps - Minimum of 16 I/O pin ports (some have more!)

That's at the base level. For each shift register that you might use, you LOSE 2 Stamp pin ports, and GAIN (at least) 8 (input or output - not both). I won't go any further unless you wish me to do so.

Regards,

Bruce Bates

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When all else fails, try inserting a new battery.

lostsouldark

I think about BASIC Stamp of course
they seems to be very good.

thanks again for all, now, I'll read docs on the Parallax site

lostsouldark

lostsouldark

I ask this question because I have a sumobot, and a boar of education, and all the sensors I talk in the first post.
and all of this is mounted in one robot. the 2 boards don't communicate, and each one have some sensors. and I'll try to put all of them on a single board, it's more simple I think.

Chris Savage

Hello,

You original post was regarding the ability of the BASIC Stamp to handle all of the peripherals sensors and devices you wanted to connect. But it seems you’re basing this on the ability for two boards to communicate, which is not related.

I/O pins can be expanded using shift registers. For the most part a shift register is going to give you an additional input or output, depending on the register. When using the same type of shift register you lose three I/O pins, but you gain them in multiples of eight. For example, if you have one 74HC595, it will take three I/O pins to talk to it, however it will provide you with eight outputs. Adding 8 more I/O pins does not consume any more I/O pins as these are serially extendable. In this case the limitation is available memory as you need a byte variable for each shift register. Adding additional SPI devices requires only one additional I/O line as these types of devices can share clock/data pins.

LCD, PIR and DS1620 are all different types of devices that take varying numbers of I/O pins and most cannot be used on the shift register pins. Perhaps clearly defining what exactly you want to do will help us outline a solution for you.

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Chris Savage
Parallax Engineering

lostsouldark

no, I don't want to make the board communicate, I don't talk about this in my first post.
I use 2 boards just because I don't know if it's possible to put all of the sensors on the sumo bot board.
I don't want to disturb you, I'll search on the web, and on the doc on Parallax.
I like to understand by myself.

thanks a lot for all of this useful informations

lostsouldark