Stamp not found error

[hobbyrobo]

Hi All,

I have been using basic stamp 2, with board of education USB rev D, usb version to build a hobby project. Everything was working great till last week. Today, as I tried to connect the circuit to my laptop, I get the 'stamp not found' error. Nothing has changed since I was last able to connect. I'm using the same laptop, same usb cable, same circuit etc. When I do 'identify' I get loopback = yes, echo = no. I checked the following,

--my usb port is com4 and that is what shows up in 'identify' screen
--I changed the batteries to power the board (4 AA cells), did not resolve the problem
--I went into control panel, changed the port settings to decrease the receive bytes and transmit bytes to 256 each (earlier they were at 4096), didn't help

I'm stuck at this point on what to do to resolve this problem. Any help will be greatly appreciated.

PS -- my laptop is an hp pavilion, with vista 64 bit OS.

thanks!!

[Mike Green]

This situation comes up over and over again and there are many past threads on the subject. There are some suggestions in one of the "sticky" threads at the top of the forum thread list. Nearly all of the cases are causes by:

1) Something wrong with the power source. If run off batteries, the batteries have been used up. If run off AC, something has gone wrong with the power supply or cable.

2) Something wrong with the serial connection between the PC and the Stamp. Something has gone wrong with the serial cable or USB to serial adapter or USB driver or USB cable.

You should not get echo = no. The BOE and Stamp module circuitry connects the serial output from the PC to the serial input to the PC and that will cause any data sent from the PC to be echoed back to the PC. Your Stamp Editor says this isn't happening.

I would recommend trying another PC, preferably with something other than Vista on it. You may end up having to uninstall the Stamp Editor and FTDI drivers, then reinstalling from fresh copies.

[C-Bob]

I think, try HW loopback - remove BS2 and conect on board pins SIN SOUT (pins 1 and 2), run hyperterminal like sw (hyperterminal not present in Vista). Write anything and you must receive the same. If not, you have defective USB>RS232 convertor, else problem is in stamp.

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C-Bob

Every problem·have at least one·nice, simply and·wrong solution.

[JD]

Hobbyrobo,

What do you get for echo and loopback when you run Identify (ctrl + I)·from the BASIC Stamp Editor?

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Respectfully,


Joshua Donelson
www.parallax.com (http://www.parallax.com)

[hobbyrobo]

Hi All,

Thanks for your inputs. Strangely enough, my stamp is working again!! I did not change anything, I just disconnected everything and tried again the next day. I'm not sure what was wrong. Power supply (AA cells) was fine, usb cable was fine, power switch on the BOE was in 1/2 positions (checked several times) etc etc. Could the error occur if I connect the usb cable first and batteries later? Anyways, I'm fine for now and will let you guys know if I run into issues again.

When I ran identify, I was getting loopback=yes, echo=no. Now it is ok. Don't know why/how.

thanks.

[logan996]

weird, i got the same problem and i just left it alone a while, and it worked again, werd...

[JD]

Gents,

It sounds like the latency time is set to 16 as apposed to 1; can you confirm what the BM latency timer is set to in the device manager? Windows defaults to 16, and that can cause a small timing issue depending on the PC; it should be·set to 1.

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Respectfully,


Joshua Donelson
www.parallax.com (http://www.parallax.com)