Need help setting up my ultrasonic distance sensor

[Acetronics2]

Hi,

OMG ...

I also think you are exceeding the Pickit sourcing authorized current ... Especially when " pinging " ...

Alain

[Megahertz]

Hi,

OMG ...

I also think you are exceeding the Pickit sourcing authorized current ... Especially when " pinging " ...

Alain

Oops! will try everything again with seperate supply and update here. May be this is the reason that it is not working.

[Megahertz]

OK, I tried with this approach and it works, but as you will see in the code, even though the object is under 5 meters away (for eg. 4meters), PORTC.2 goes high & does not toggle. Is there something wrong with my calculation. It is working fine upto 1 meter. LED connected to PortC.2 does alterate it's toggling speed depending upon how far is the object under 1 meter. My latest code goes like this:

; Phase2: RA0=TRIG (OUTPUT) ;;;;RA1- PWM (INPUT)
w1 var word

pause 500
main1:
w1=0
High PortA.0
pause 1
Low PortA.0
pause 1
High PortA.0

main:
Pulsin PortA.1,0,w1
if w1>500 or w1=0 then 
		high PortC.2
	else
		toggle PortC.2
			pause w1
	endif
goto main1
end

[Acetronics2]

Hi,

Everything works as written ...

W1 = 500 is a distance of 1 meter ...

...

try 2500 instead ...

and note no measure will send back ... 5000 Pulsin units ( 50 000 µs )

Alain

[Megahertz]

Hi,

Everything works as written ...

W1 = 500 is a distance of 1 meter ...

...

try 2500 instead ...

and note no measure will send back ... 5000 Pulsin units ( 50 000 µs )

Alain

Hi, it works fine with 2500. Can you please explain how you calculated 2500? Thanks

[mackrackit]

500 multiply by 5 meters...

[Acetronics2]

Hi, it works fine with 2500. Can you please explain how you calculated 2500? Thanks

Being Honest ...

1) read Datasheet Page 3 ...

4: PWM - PWM Output 0－25000US，Every 50US represent 1cm

2) read PbP Manual page 133 ...

The resolution of

PULSIN is dependent upon the oscillator frequency. If
a 4MHz oscillator is used, the pulse width is returned in 10us increments.

3) The distance is 5 meters = 500 cm

from 1) and 3) ...

4) Pulse will be 500cm * 50µs/cm = 25 000 µs

from 4) and 2) ...

@4 Mhz Pulsin will return 25 000 / 10 = 2 500 units

This is the mathematical explanation of zeu thing

Alain

PS@ Dave

Don't you think I should add " Need Help " in my signature validity conditions ???

[mackrackit]

PS@ Dave

Don't you think I should add " Need Help " in my signature validity conditions ???

Yup, need help understanding data sheet.

I think Megahertz is doing fine, sometimes know where to look is a bit different than knowing what to look for.

I just spent parts of two days trouble-shooting a machine. Tried this and that, read the manual, tried other stuff, back to the manual.....
Then the great thought hit me... I wonder if that cable on the floor should be plugged into something