UM232R and Basic Stamp

bryan costanich

Has anyone here gotten the UM232R and the basic stamp working? i'm having some trouble.

i've configured the UM232 in a self-powered configuration as shown in the attached file.

i've supplied it with 5v DC.

i've configured the basic stamp as shown in the BS2 schematics. i've hooked up the SOUT, SIN, VSS (pins 4&23) and i've supplied 5v regulated voltage to VDD (pin 21) [noparse][[/noparse]i have not hooked up the reset pin (still trying to figure out how to get a reset signal from the um232r chip).

i then installed the um232r drivers. they worked fine. it created a virtual com port at com3.

then i opened up the basic stamp editor and click identify. it shows me com3. tells me i have echo but no loopback (according to the docs, this is normal with usb since loopback is wonky.) however no basic stamp is found.

any ideas why it's not finding the stamp? any ideas on how to debug it? i've double checked all the connections and order as well as the the power, and as far as i can tell the um232r is working properly. (i was able to install the virtual com drivers for it just fine.)

one note is that i don't have the ATN pin (pin 3) on the basic stamp hooked up to anything.

Post Edited (bryan costanich) : 3/10/2007 8:48:54 PM GMT

Franklin

You need to tie the ground from one device to the other so the signals between them have a reference.

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- Stephen

bryan costanich

they are both ground to the same ground bus. see the second image.

Chris Savage

ATN is required to identify or program the BASIC Stamp. That pin is used to reset the BASIC Stamp before these functions. I am not clear on the #RTS & #CTS connections you show on “MCU” since the BASIC Stamp does not have these connections.· It just occurred to me I have already answered this before in a duplicate thread.

Please refer to the original thread at the link below for all future replies.

http://forums.parallax.com/showthread.php?p=631909

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Chris Savage
Parallax Tech Support

bryan costanich

Actually, the other thread was dealing with another specific issue - how to interface the reset pin on the stamp. I didn't realize the issue i posted here was because of the reset problem.

the "MCU" diagram came straight from the UM232R datasheet. it's a generic diagram for micro-controllers, not just the stamp, hence the RTS (ready to send) and CTS (clear to send) in the diagram.

the question of how to get a reset pull up from the UM232R still stands in the other thread, i guess getting an answer to that will hopefully fix my problem here.

sorry for the duplicate thread, they really did begin as different questions.