obstacle sensing circuit

[khangzing]

i'm having TSAL6200 emitter,Tssp6p38 receiver ,pic16f877a mcu and apr9600 voice chip.

the basic idea was when obstacle detected,mcu will activate the voice chip and alert the blind.

i stucked on emitter side,how can i modulate the signal without using mcu?can show me the circuit?

 

[crutschow]

What type of modulation do you want?

 

[khangzing]

I need to modulate my ir emitter to 38khz,how to do?i tried with 555 ic and I can't get 38k

 

[crutschow]

A 555 astable should readily oscillated at 38kHz. Post your circuit diagram.

 

[khangzing]

https://techmagnanil.blogspot.com/2012/04/8051-microcontroller-hobby-project.html

please see the transmitter side,this is the circuit i used to produce the 38khz signal.

by the way,if i only using the internal clock of PIC16F877A,will it function?i mean to modulate the signal?my receiver is tssp6p38 and this is the receiver.

https://www.electro-tech-online.com/custompdfs/2013/04/tssp6p38.pdf

 

[crutschow]

So did you use the component values shown in Figure 3.1?

What output frequency of your 555 do you see?

 

[khangzing]

ya i used,but i only use 1 TSAL6200 emitter,in figure 3.1 it show 2 emitter,and what i measured is only 4.5khz -.-

 

[crutschow]

What happens to the frequency when you adjust the pot?

 

[khangzing]

nothing happen -.- do you know how to modulate it by crystal oscillator?or the internal clock of microcontroller? i'm using PIC16F877A. do you have any reference circuit?