line tracing using TSOP

[k_ishan]

Hi guys.........
i have tried TSOP-1738 alongwith IR led as an obstacle detector.......
its output goes low whenever obstacle comes in its range......it remains high otherwise.......
i think it can also be used to trace the line ......
i think its outout should go low on white line as IR light will get reflected from white and it should remain high on black line as IR light will not get reflected from black and it'll not detect black line as an obstacle
but in case of TSOP-1738 THIS IS NOT HAPENNING .........
CAN U PLEASE HELP ME........

 

[ericgibbs]

Hi guys.........
i have tried TSOP-1738 alongwith IR led as an obstacle detector.......
its output goes low whenever obstacle comes in its range......it remains high otherwise.......
i think it can also be used to trace the line ......
i think its outout should go low on white line as IR light will get reflected from white and it should remain high on black line as IR light will not get reflected from black and it'll not detect black line as an obstacle
but in case of TSOP-1738 THIS IS NOT HAPENNING .........
CAN U PLEASE HELP ME........

hi,
The TSOP requires a pulsed emitter pattern for correct operation, not on/off IR line detection. datasheet.

 

[k_ishan]

hi,
The TSOP requires a pulsed emitter pattern for correct operation, not on/off IR line detection. datasheet.

yeah, i know it ......................
i have applied 38khz pulses(square wave).........

 

[ericgibbs]

yeah, i know it ......................
i have applied 38khz pulses(square wave).........

hi,
Are the pulses of the emitter produced to this specification.? 10 to 70 pulses and a gap of 14 pulse periods.?

A continuous 38KHz pulse rate will not work, look carefully at this image

 

[k_ishan]

hi,
Are the pulses of the emitter produced to this specification.? 10 to 70 pulses and a gap of 14 pulse periods.?

A continuous 38KHz pulse rate will not work, look carefully at this image

I am not getting what is the BURST LENTH??????????/

 

[ericgibbs]

I am not getting what is the BURST LENTH??????????/

Its the number of pulses in the 10 to 70 pulses, if you know the period of the pulses you can work out the Burst length [period]

Note what it says about a continuous 38KHz signal, in the 'errors' section.