8 bit parallel bus between multiple stamps

kennet

Hello All,

I am thinking of using an 8 bit parallel bus system between multiple stamps ( 9 ) in order to have all command subroutines within the system·addressable and able to be tested with out a controller.·This will allow the Master Stamp , PC , R/C Transmitter or even a cell phone·to control·the robot. I also beleive system will keep the code simple.Could I acheive the same type of·multiple control and code saving using the SERIN/SEROUT commands?

Ken

Ugha

Why not use a serial line and a control line? That'd only take 2 pins and it'd still be pretty danged fast.

kennet

You are absolutely correct. What was I thinking. Wait a minute. I wasn't thinking. I'm always trying to make things more difficult that they need to be. Thanks

Ken

Ugha

Glad I could help [noparse]:)[/noparse]

I've toyed with this a few times myself.

There's a very helpful Nuts and Volts article called A Tale of Two Stamps.
I don't have time to look up the URL for you... but it's there, somewhere.

Be careful about driving lines high/low at the same time... make sure that your careful
with controlling the serial line.

Edit:
I'm attaching a schematic I made up for a future project that ties two stamps
together and shares an external EEPROM. This is based on several sources including
the Nuts and Volts article I spoke of. Note that this circuit is untested by me but
in the forum post I posted it in originally, everyone said it'd most likely work and be
safe.

To make it just communicate between two stamps, just leave out the bits that
connect to the EEPROM (SDA and SCL).

If you need the values for the various resistors and such, let me know and I'll try
to dig up the original post.

Post Edited (Ugha) : 3/21/2008 3:59:30 PM GMT

kennet

Thanks Ugha, Its your world! Beleive it or not, I've been trying to figure out the Nuts &Volts article 'A Tale of Two Stamps' for months now. I could not figure the communication protocol because it was written for a different type of application. The robot I'm building has several Stamps. One Stamp controls 3 motors . Two Stamps control 4 motors each. Two Stamps control 4 servos each and one Stamp controls two servos. Each Stamp will be running at least 10 subroutines . I was trying to figure out how to run any subroutine in any Stamp with a BS2p40 or a Laptop PC using Serin/Serout .

If I'm not mistaken, I need to assign each subroutine a Hex number then use the Serout command to send that number,correct? The Serin command and flow control will automaticcally monitor the timing, correct? Also your External EEPROM,Two Stamp circuit looks cool! I didn't know it was possible to use an external eeprom with the BS2.

Ken