What does it mean when the green light goes out

vla7

I have a basic stamp homework board which runs on a 9 volt battery.
The green light on the stamp will turn off while a downloaded program is running and my motors will either stop or just continue to spin.· (they are powered by a seperate 2 AA batteries) Does this mean my battery power (9 volt) is low?· Or is my stamp overheating and shutting off?
·

Mike Green

The green light on the Homework board normally goes out while something is being downloaded. It also goes out when the Stamp is stopped by a NAP, STOP or END statement. I don't know how you're controlling the motors, but the I/O pins of the Stamp get set to input mode when the Stamp is reset (as on a download). For most attached logic, this is an indeterminant state. You can use pull up or pull down resistors (like 10K ohms to +5V or ground respectively) to define the logic state when the I/O pins are in input mode.

vla7

Can you take a look at my program and see if there's something causing the light to go off.· It's a simple program that uses the pololu micro dual serial motor controller.· My intentions is to have the robot go forward until a switch is trigured causing it to backup, spin in place and proceed forward again until the switch is trigured again.· It works fine for about 30 secs of so (it's not consistant), then the green light goes off and the motors stop responding to the switch.· I connected the reset on the motor controller through a 4.7kom resistor to the logic supply.· Is there something else I should be doing?

Mike Green

What you describe usually means that the battery is exhausted. Try a new one. 9V batteries have fairly low current capacity and go dead much faster than you think they should. They're OK for short experiments, but not for any continued use.

Franklin

Get a four pack for AA, C, or D alkaline batteries they will last forever.

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