UARTt 16f887 configuration reception and transmission

[jayanth.devarayanadurga]

You need MAX232. MCU pins are TTL/CMOS level and RS232 voltage is different. Google for TTL voltages and RS232 voltages.

 

[betwixt]

You only need the MAX3222 if you are going to drive cables to another RS232 device at the other end. You can drive the UART through a current booster to an LED but you might have other problems if you do that. It depends on the distance the light beam has to travel and the environemnt it has to work in. If you are using it in an open environment the biggest problem you will face is other light sources reaching the receiver and being mistaken for your data. Also be careful if you use a high current through the LED that you have it default to OFF when the data line is idle or you may face heating problems.

Brian.

 

[lotfibedui]

i just want to ask
when using the uart
is there need to use microcontroller like MAX3222
i want to develop visible light communication
computer --> uart --> transistor --> LED
so is there need to use microcontroller between uart and transistor to make LED blinking?
or uart alone can do the task?

you should use Max232, for example, between your serial port and your pic
his role is the adaptation of signal between the UART and the serial port
you can have more detail in this subject if you search Max232 with google

 

[betwixt]

That conflicts with the "visible light communication" requirement which I assume means sending serial data over a light beam. For that there is no need to use a MAX3222 or MAX232. Perhaps the OP can clarify exactly what they want as there is already a UART in the PC.

Brian.

 

[palie90]

thanks
i think i just use usb to uart(uc00b)
the voltage is fixed to 3.3 or 5
am i right?
if anyone had done visible light communication
please share knowledge with me
because visible light communication is my final year project in university