Rs -485 & RS-232 comapability

[ratan.1185]

Dear all ,

I am doing a project in which I have to use GSM modem & ARM based controller ,LPC 1768.
My query is that, As UART of LPC 1768 support RS485 but GSM modem supports RS-232 . so how can I commumnicate between them.

 

[djsfantasi]

The two types of interfaces are not directly compatble. Quote: "RS485 interface gives some more benefits compared to RS232: simplicity and the robustness for long distance transfer. RS485 is simpler because it uses only two ire (or a single pair) to carry out the data in bidirectional manner, using RS232, we need 3 wires at minimum to carry the data bidirectionally. RS485 cable length can be as long as 1.2 km, while RS232 only about 25 meters."
There are many circuits available and on this forum, too! Search the forum for "rs232 rs485 converter" and see if you can find what you need.

 

[mrcube_ns]

Simple make RS485-RS232 converter.

Use google, you can find a lot schematics.

try:
RS232<=>RS485<=>RS422 Converters

There you can find lots schematics for converter.

Mr.Cube

 

[akvii]

here is the schematic which i made and its working



u can use max485 or 75176 as 485 IC and max232 for 232 IC