serial cable with 18m2 and L293D

A

Alex3k

Member
Hey guys, so in a previous topic of mine (http://www.picaxeforum.co.uk/showthread.php?19095-Limiting-D.C-motor-angle) i was trying to figure out how to use a motor to control a webcam (pan and tilt) and after looking at manual 3 i found using a L293D would allow me to control two motors with ease.

So the aim of this is to use the input from a computer to control the webcam, everything is done however I can not use a 08m chip as i need to serial inputs therefore i am one output pin short therefore the next chip i have is a 18m2 (bit of a leap). when i plug in my serial cable to the breadboard all of the output pins go to approx (varies) 0.75v i dont know why... I have dinner now and when i come back i will make a circuit diagram however i wanted to get the ball rolling....

This is very confusing.

Cheers for the help once again.

Alex
 
E

eclectic

Moderator
Alex3k said:
Hey guys, so in a previous topic of mine (http://www.picaxeforum.co.uk/showthread.php?19095-Limiting-D.C-motor-angle) i was trying to figure out how to use a motor to control a webcam (pan and tilt) and after looking at manual 3 i found using a L293D would allow me to control two motors with ease.

So the aim of this is to use the input from a computer to control the webcam, everything is done however I can not use a 08m chip as i need to serial inputs therefore i am one output pin short therefore the next chip i have is a 18m2 (bit of a leap). when i plug in my serial cable to the breadboard all of the output pins go to approx (varies) 0.75v i dont know why... I have dinner now and when i come back i will make a circuit diagram however i wanted to get the ball rolling....

This is very confusing.

Cheers for the help once again.

Alex
Click to expand...
Alex,
1. Please post your FULL circuit schematic and program.
A HQ photo might help as well.

2. For excellent background, read
http://www.picaxeforum.co.uk/showthread.php?9425-Pan-and-tilt-control-of-webcam-with-PICAXE-08M&highlight=webcam


http://www.picaxeforum.co.uk/showthread.php?9192-Pan-and-tilt-mechanism&highlight=webcam
http://www.picaxeforum.co.uk/showthread.php?13705-Rivercam-with-PICAXE-pan-tilt-control&highlight=webcam


e
 
Last edited:
hippy

hippy

Ex-Staff (retired)
A circuit will help but a good first check will be that you've got the 10K / 22K 'download circuit' right and the connections in the right order.

If it's just an additional serial in you need for your 08M you could consider moving to an 08M2 and using SERRXD. That should be a drop-in replacement for what you seem to already have.
 
E

eclectic

Moderator
Alex3k said:
What software can you recommend for drawing the diagram?
Click to expand...
Many available.
I use Express Sch, but there are many others.
They all take a couple of hours to learn.

A good quick way to start is

Graph paper, a ruler and a thick pencil.
Draw the schematic, then scan it.

Post as a jpg.

e
 
M

MartinM57

Moderator
Alex3k said:
I have dinner now and when i come back i will make a circuit diagram ... This is very confusing.
Click to expand...
I agree. I don't think anyone could spot where the problem lies from the photos unfortunately. A nice clear diagram plus a check by you that the breadboard circuit EXACTLY matches the diagram will, I'm sure, lead to lots of assistance.
 
A

Alex3k

Member
well cheers for your help guys, i got half way through drawing it which took a while... im not exactly the neatest person around and then decided for a third time lucky in taking it apart and re doing it and with sucess :) its all working well now :D

I do however have one question, I have noticed using the High command with my picaxe chip (18m2) the voltage output from the pins varies between 2.3v to 5.1v... is there a way to make sure it gives atleast 4v?
 
M

MartinM57

Moderator
...well that's not normal. What's connected to it?...and a small circuit diagram of that part of the circuit would definitely help or else we are all guessing ;)
 
A

Alex3k

Member
... nothings connected to it, ive started it all again and at the moment i have the serial connection circuit from manual one for the 18m2 chip
 
A

Alex3k

Member
Solved the problem. it was becuase i was using 200ms but as the time increases it gets stable ground.... :p cheers... Has anyone had any expierence with a L293D? have they found it good ?
 
E

eclectic

Moderator
Alex,
can you please post

your current circuit.
your current program(s)

It's very difficult to keep track of what you are doing.

e
 
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