Discussion in "General help Guidance and Discussion" started by    Mamat    Nov 4, 2010.
Wed Feb 09 2011, 09:10 am
i try many way and get more info from ajay and member,now my wireless is work.circuit is like this
pic(5v)---max232---max3232---xbee pro(3.3v)

but when i try using voltage divider without using any max only connect pic with xbee its not work.i don"t know why.i now i proceed with my work circuit.

thanks to ajay and master member and this forum
Wed Feb 09 2011, 09:18 pm
it really work?
if my uC is at89s52? did the circuit will work or not?

Thu Feb 10 2011, 01:36 pm
@ posto
about which circuit ur referring

@ Mamat
which resistor values u try

Thu Feb 10 2011, 04:45 pm
i refer left this image majoka

Thu Feb 10 2011, 05:52 pm
to interfacing xbee / 8051 better with voltage dividers ?

if i intefacing pin dout/din xbee to pin tx and rx 8051 without voltage dividers , what will happen?
Thu Feb 10 2011, 05:57 pm
xbee understand 3.3 as high logic and 8051 also can understand 3.3 as 1 volt but if u give high voltage at xbee pins it may damage that is risky and it is costly part of circuit so do not get risk
Sat Feb 12 2011, 08:43 pm
if i was making this circuit i would be doing this way:

8051/PIC RX <------- XBEE TX (direct no need of voltage conversion)

8051/PIC TX --------> XBEE RX (need a conversion)

conversion methods:
1. Simplest use voltage divider. works 90% make sure your resistors are with gold rings
2. transistor circuit... much reliable.
3. put 2 diodes and a small resistor in series.. 1N4148.
each diode drops 0.7V so two diodes 1.4, so 5V - 1.4V = 3.6V (pretty good) + a resistor (1K) for current limitation. you will hardly fear damaging your xbee

all methods are good.. you can choose which one you want.
Tags 5V to 3.3v conversion8051 xbee connectionpic xbee connectionxbee module with 8051xbee with pic micro
Mon Feb 21 2011, 07:22 pm
oh tq.

ajay my place max3232 not have,
only max232 have in my place.

so, what should i do. to interfacing xbee to pc?
did any solution ?

Tue Feb 22 2011, 02:23 am

ajay my place max3232 not have,
only max232 have in my place.

so, what should i do. to interfacing xbee to pc?
did any solution ?


The safest way is to get a max3232, they are a lot cheaper than Xbee modules

If not, use a Max232 run from 5 volts, run the Xbee from 3.3 volts, and use one of the
methods in Ajay's latest post to connect them.

[ Edited Tue Feb 22 2011, 02:25 am ]
Wed Feb 23 2011, 07:24 pm
there are other 3.3V RS232 line drivers available in market, look for them. There is a similar IC available from TI too and same price if i remember

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