Question on UART,TTL,Serial and USB to Serial Cable to Root

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zenofex
2.1 Eclair
Posts: 173
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Re: Question on UART,TTL,Serial and USB to Serial Cable to R

Post by zenofex »

You may want to get a multimeter and verify that RX/TX are communicating at 3.3v, a lot of the USB TTL setups I've seen are 5v so after verifying that you'll also want to make sure that you're serial settings are set at 9600 baud with 8-N-1 (8 data bits, no parity bits 1 stop bit).

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Zenofex
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swapped
Android 1.0
Posts: 16
Joined: Thu Aug 11, 2011 10:08 am

Re: Question on UART,TTL,Serial and USB to Serial Cable to R

Post by swapped »

while i am not absolutely sure, i believe that ttl is the inverse level of serial (given same voltage levels). What i mean by that is even if it was 3.3V (even though 5V should not do any damange, u can usually drive inputs with higher voltage) when a ttl converter outputs 10110011, a serial converter would output 01001100. So esentially you would need to have 2 inverters to make this work, or you could buy a $4 usb>ttl device and wait for it. Mine took about a week to ship from china (got it on ebay).

Edit:
I guess a better way of saying this would be:
A TTL Logic 0 is the equivelent of a Serial Logic 1 and vice versa.
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