High is low and low is high!?

J

Jamcof

New Member
Hello! I am new here.

So I just have bought 08M2+ microprocessor.
Well, I downloaded simplest program.
This:
Code: 
High B.2
When I run this program the LED is not turned on, it's off. And when I type low instead of high, the LED turns on!
How is it possible? I have connected all correctly on my breadboard, double checked everything.
This happens on B.1, B.2 and B.4 pins expect B.0 is everytime turned on.
Everything is like reversed.

Help me please.
Thank you.
 
B

bpowell

Senior Member
I'd like to see how you have it connected on your breadboard...can you share a picture?

It sounds like you have the LED connected to power on the breadboard, and so when the PICAXE is HIGH, there is no difference in potential, so the LED doesn't light...when the PICAXE goes low, then you have a path for the the electrons, and the LED lights up.
 
hippy

hippy

Ex-Staff (retired)
And as a picture is worth a thousand words; your LED is probably wired as bpowell says, as on the left, rather than as on the right -
Code: 
           V+ -.-
              _|_
---.         _\ /_       ---.
   |    ___    |            |    ___
   |---|___|---'            |---|___|---.
   |                        |          _|_
---'                     ---'         _\ /_
                                        |
                                    0V -^-
 
W

westaust55

Moderator
@Jamcof,

Firstly, welcome to the PICAXE forum (this is your first thread of posts).

If you look at PICAXE manual 3, (see link for manuals on the toolbar at top of these pages)
That documents includes information on connection and operating
/sensing numerous basic devices.
In the case of an LED the information is on page 9:
http://www.picaxe.com/docs/picaxe_manual3.pdf#page9
Showing both arrangements with LED to +5 Volt and also to 0 Volts.
 
rq3

rq3

Senior Member
Jamcof said:
Hello! I am new here.

So I just have bought 08M2+ microprocessor.
Well, I downloaded simplest program.
This:
Code: 
High B.2
When I run this program the LED is not turned on, it's off. And when I type low instead of high, the LED turns on!
How is it possible? I have connected all correctly on my breadboard, double checked everything.
This happens on B.1, B.2 and B.4 pins expect B.0 is everytime turned on.
Everything is like reversed.

Help me please.
Thank you.
Click to expand...
A HIGH pin is a bathtub faucet supplying water. A LOW pin is a bathtub drain. The led is a check valve which will let the water flow only one way.
 
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