JSN-SR04T Ultrasonic Module Problem

[YGSH]

Hello guys,
I am using this module jsn-sr04t, and getting the proper output upto 3 meters. Pulse width decreases when object come near to sensor.... Upto this is OK.
But the main problem associated with this is, proper output is from 300mm. If object coming more close to it(Distance less than 300 mm) then instead of of decreasing the pulse width, it is increasing it,which creates the problem in my application.....
Do you all also getting the same problem........If yes then there is no meaning in using the this module........

 

[paulfjujo]

hello,


if your hardware ultrasonic interface is the same as this
you can meaure from 20 or 30 mm minimum , up to ~4meters or more

or you have a problem in your software ..
Check
roll over of timer used as counter ?
type of variable Char,int,long ?
delay betwen start first pulse (trigger) and beiginning of feed back
..etc ..
show your code

 

[YGSH]

I am back with the pulses.
Image 5) Object is 800mm from sensor- Module gives proper pulses-(OK).
Image 4) Object is 500mm from sensor- Pulse width decreases-(OK).
Image 3) Object is 350mm from sensor- Pulse width decreases-(OK).
Image 2) Object is 100mm from sensor- Pulse width changes randomly- (NOT OK).
Image 1) Object is 40mm from sensor- Pulse width increases- (NOT OK).

 

[paulfjujo]

:blah: not enough data .. to be able to give any answer or proposal !

:?: Show your code !

 

[FvM]

I see JSN-SR04T specified with a 0..250 mm blind range. Somehow expectable with a single transducer echo sensor.