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Topic: TC35 GSM development board (from eBay) - Confused (Read 1 time) previous topic - next topic

mikecurry

Jan 21, 2011, 02:06 am Last Edit: Jan 21, 2011, 02:19 am by mikecurry74 Reason: 1
So I just bought, and received this (from eBay):

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280594950250

Here is the schematic:
http://ihome.ust.hk/~cs_chwab/SCH/TC35SCH+PCB.pdf

This description states that it can do (RS-232/TTL) - before I plug in to this and blow my arduino or the card up, this board has a MAX232 on it, can I use TTL (tx/rx?)

I have hard times with schematics, as I am just learning, could someone take a look and see if I can just use TTL?


Update:  So I read up, and I know what the MAX232 chip does.  I want to use TTL, so I suppose what I want to know, is where can I bypass that chip and go straight to TTL?  (if someone could help me out and explain, as I don't want to blow this thing up)

gardner

#1
Jan 21, 2011, 03:14 am Last Edit: Jan 21, 2011, 03:17 am by gardner Reason: 1
One side of the MAX323 is RS232 (+/-12V) and the other side is TTL.  You can tap into the TTL level signals.  The schematic you pointed to shows JP2 being a perfect place to tie into the TTL level signals before they go to the MAX232.

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