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Re:lpc 210x Uart1 modem interface

2005-04-28 by Owen Mooney

If you can get behind the RS232 driver in phone then you will
be able to make a direct connection from the 2106 ports to the 
corresponding micro ports of the phone (both should be 0 to 3.3 volts)

If you can't, then you cannot directly connect the 2106 ports to the 
data lines from the cdma phone. The line will not only be inverted, but
also have voltages outside the acceptable range of the 2106 ports - typically +/- 6 V.

An easy solution is a transistor invertor on each of the 2106 lines.
Use a fet and resistor for the tx line, and a npn transistor and resistor for the rx line

You can also get a tiny dallas chip that will do all of this

Owen Mooney
 

Subject: 

   hi
i m final year elect. engg student
in my project i m interfcing lg cdma phone with 
lpc 2106 . this cdma phone has data cable which
contains rs 232 converter in it.
normal rs 232 drivers such as max 3232 gives inverted
outputs & modem interface pins of uart 1 are active
low so total system works perfectly
but i want to remove that rs 232 converter & i havent
provided inverter in hardware . what is the software
solution so that system will work perfectly?

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