At 08:14 AM 4/28/05 +0100, rohan patil wrote: > 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?
Out of curiosity, why have you ruled out using a RS-232 level
convertor? It strikes me as a cleaner and easier solution unless you are
building 1000's.
Robert
" 'Freedom' has no meaning of itself. There are always
restrictions, be
they legal, genetic, or physical. If you don't believe me, try to chew a
radio signal. " -- Kelvin Throop, III http://www.aeolusdevelopment.com/
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?
Reply by sudip nag●April 28, 20052005-04-28
If are you trying to connect directly from LPC UART pins to mobile
phone's UART eliminating RS232 transceivers in both end, there need not be
any software change. You have to open the phone cover and solder onto PCB. No
hardware inverter is required. But do not connect LPC pins directly into phone
RS232 jack.
Sudip Nag
rohan patil <iamrohanpatil@iamr...> wrote:
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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Reply by rohan patil●April 28, 20052005-04-28
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?
________________________________________________________________________
Yahoo! India Matrimony: Find your life partner online
Go to: http://yahoo.shaadi.com/india-matrimony
