Output pin voltage

Community General Discussions
1

Hello! I'm working on a Picaxe 28x1. I can't find in documentation what is supposed to be the voltage of the output pins.

I've used a tester to check and it's very low, about 1, 1.5 Volts. Is it normal that it's so low ? Is that enought to use with a transistor?

Thanks :)

2

How much are you feeding

How much are you feeding it?

/ Fritsl

3

i’m feeding the picaxe with

i’m feeding the picaxe with 4.8V (4*1.2 rechargeable AA battery). I’m also using an L293D IC, can it be the cause? I’ve read it causes a voltage drop, but that much ?

What should the right value be, anyway?

Thanks :slight_smile:

4

Well it all depends on what

Well it all depends on what / where you are measuring :slight_smile:

The Chip sends out TTL-level - which is 0-5V (if it is fed 5V - but then there is the darlington, and the motor driver… I am not quite sure what you are measuring…?

/ Fritsl

5

thanks fritsl :)I’m

thanks fritsl :slight_smile:

I’m measuring the difference between an output pin in the board (the block marked F in this image) and the ground.

perperials1.jpg
perperials1.jpg476×500 58 KB

 

If a device says "connect with TTL level" can i connect with my weak 1,5 V output ?

Btw, what is the Darlington needed for?

6

"F" goes through the

"F" goes through the Darlington. It is sort of an amplifier. There are many issues in your different questions :slight_smile:

So… to put it short; If you want to connect to TTL, you should use the “E”-row, not the “F”.

/ Fritsl

7

Hey, See what Mr “psy” has

Hey, See what Mr “psy” has made here:

https://www.robotshop.com/letsmakerobots/node/662

You may want to read that!

/ Fritsl

8

hithe output voltage int the

hi

the output voltage int the picaxe 08m2 chip, when output hight is:

High Range: VOUT = VDD - 4VT

 

output low:

Low Range: VOUT = VDD - 2Vt

 

where vdd: Positive supply voltage

vt: threshold voltage