High and Low code

A

Alex3k

Member
Hey guys,

So what i have is a program written in vb.net that works that sends the letters "u", "d", "l" and "r" via serial cable to the 08m chip i am using.
The vb.net program works as ive used it many times before.

I have the code below, it is supposed to turn on pin 1 and 2 when the specific letters are entered... i checked the pins with a digtal multi meter and it reads only 0.22v not the expected 5v... Can someone help?


Code: 
main:
	Serin 3, N2400, b0
	
	select b0
		case "l"
			high 1
			pause 500
			low 1
			
		case "r"
			high 1
			pause 500
			low 1
		
		case "u"
			high 2
			pause 500
			low 2
			
		case "d"
			high 2
			pause 500
			low 2
			
	endselect
	
	
	goto main
 
E

eclectic

Moderator
Alex3k said:
Hey guys,

So what i have is a program written in vb.net that works that sends the letters "u", "d", "l" and "r" via serial cable to the 08m chip i am using.
The vb.net program works as ive used it many times before.

I have the code below, it is supposed to turn on pin 1 and 2 when the specific letters are entered... i checked the pins with a digtal multi meter and it reads only 0.22v not the expected 5v... Can someone help?


Code: 
main:
    Serin 3, N2400, b0
    
    select b0
        case "l"
            high 1
            pause 500
            low 1
            
        case "r"
            high 1
            pause 500
            low 1
        
        case "u"
            high 2
            pause 500
            low 2
            
        case "d"
            high 2
            pause 500
            low 2
            
    endselect
    
    
    goto main
Click to expand...
I have NO knowledge of vbnet, just two questions.

1. How did you get it to work originally?

2. What is your present circuit and how does it differ from the "working" one?

e
 
hippy

hippy

Ex-Staff (retired)
Alex3k said:
i checked the pins with a digtal multi meter and it reads only 0.22v not the expected 5v... Can someone help?
Click to expand...
Are you using a project board which has a ULN2803A Darlington driver on it ? If so those will be open collector outputs, can only sink current not source it. Check with the meter probe directly on the PICAXE leg but take care not to short two legs together !
 
A

Alex3k

Member
hippy. i am using a simple bread board.
eclectic - yeah i can get it working using fully functional servos. the only thing i have changed is that a signal wire (white servo wire) was connected to the output now the power wire to the dc motor is connected to the output and the black wire from the motor is connected to ground. in theory this should work right?
Also am i right in sayign that a 08m chip at the output should give 5v not 0.22v?
 
E

eclectic

Moderator
Alex3k said:
hippy. i am using a simple bread board.
eclectic - yeah i can get it working using fully functional servos. the only thing i have changed is that a signal wire (white servo wire) was connected to the output now the power wire to the dc motor is connected to the output and the black wire from the motor is connected to ground. in theory this should work right?
Also am i right in sayign that a 08m chip at the output should give 5v not 0.22v?
Click to expand...
WHAT circuit?

Gives up.
 
A

Alex3k

Member
The 08m normal circuit from manual 1 with a motor attached to the output pin 1 and another motor attached to the output pin 2
 
A

Alex3k

Member
ive just realised that its when the motor is connected that the output 1 voltage drops from 5v to 0.22v...
 
Technical

Technical

Technical Support
Staff member
You cannot connect a motor without an interfacing ciruit. You will damage the PICAXE chip, in fact you may well have done so already.
Look up motors in part 3 of the manual, they are very different to servos (which take a logic signal and so can connect direct).
 
Technical

Technical

Technical Support
Staff member
That would work, as would building an electronic circuit (e.g. L293D) to interface your motors. Your choice.
 
You must log in or register to reply here.
Top