infrared transmitor using TSOP and microcontroller

[marian]

hello i have some problems with an infrared transmision, i am trying to send dome data between computer and microcontoller .

for this i am usnig an 555 timer thet givese me 38 Khz output (i saw an osciloscope and it jams all TVs so it wirks),this the 555 timer is alimentated from 5 vols and the output high is at 4.3-4.4 v. (on osciloscope)

  the data is send using UART transmision from microcontrroler set at 2400 bps and put in a nand gate ciscuit with the 555 time output. so the driver for IR LED sands 38 KHz when the TX UART signal is high

 

   for reception a am using an TSOP31238 integrated ir recever that i conect to an MAX232 and to computer.

  so i am trying to sand some characetrs on hyperterminal, on computer it is not what i am sanding

 

    can you have some ideea why is this not working,  i  tryed to invert de output of tsop and stil is not working,  should i chose an lower transmision rate, the output of tsop is to low, i mesured and it give 4.8 volts when no signal in send or the nand gate can not work with the output of 55 timer (the voltage is to low or the frequency to wigh (i dont thinck it has something with frquency) ).

 

  an other question is thai it is ok to  sent data directly from usart, this protocol is high all the time and is put on 0  before transmitins so the the output of the driver (38 Khz beam) is on most of the time so the TSOP detect always 1  , it this fine for tsop circuit or shoul i invert the output of uart before nand gate ?

 

  i can provide the scematisc but i have resumed all 

thank you and plese help

[SHAH DISHANT H.]

Hi,

Can you pls send schematic and program? Issue seems with program. Have you tested software alone?

 

Anyways, post both the things and we will solve it.

[Author]

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