TC35i GSM With PIC 16F690 help

[pedja089]

max 232 is logic level converter. It converts RS232 logic level to ttl logic level and ttl to RS232. You should look datasheet.

[financecatalyst]

Thanks for the info but since I am fairly new to this field, can you guide me as to where I can read about TTL & RS-232 type signals and difference between them.

[mackrackit]

http://en.wikipedia.org/wiki/RS-232

http://en.wikipedia.org/wiki/Transis...ansistor_logic

Is a start...

[pedja089]

On google or wiki
RS232 standard:
logic "1" is -3 to -15V
logic "0" is 3 to 15v
-3 to 3 is not defined
TTL standard:
logic "1" is 2 to Vcc (usually Vcc=5V)
logic "0" is 0 to 0.8V
Edit:
0.8 to 2V isn't defied

[financecatalyst]

On google or wiki
RS232 standard:
logic "1" is -3 to -15V
logic "0" is 3 to 15v
-3 to 3 is not defined
TTL standard:
logic "1" is 2 to Vcc (usually Vcc=5V)
logic "0" is 0 to 0.8V
Edit:
0.8 to 2V isn't defied

Thanks. I am trying to send an SMS using TC35i & 16F690. I tried to replicate the schematic at this link: http://techni.caliti.es/blog/2008/12...ontroller.html
I used the pins 10 & 12 of 16f690 instead of 17 & 18 of 16F873. Hope it will work

[aratti]

I used the pins 10 & 12 of 16f690 instead of 17 & 18 of 16F873. Hope it will work

If you have in mind to use the downloaded software, the answer is IT WILL NOT WORK.

If you will write your own software the answer is YES IT WILL WORK.

Al.

[financecatalyst]

If you have in mind to use the downloaded software, the answer is IT WILL NOT WORK.

If you will write your own software the answer is YES IT WILL WORK.

Al.

Hi Aratti, your project has inspired me to do one by myself. I wont be connecting to the computer (as it does not have an serial port) neither I can get 16F873 that easily. So I am using 16F690.

Any advise as to how to set up the registers, correctly for 690?

[aratti]

Any advise as to how to set up the registers, correctly for 690?

With pic 16F690 you need to turn off analog port to make them digital. You will accomplish this with the following instruction:

ANSEL = 0 : ANSELH = 0

In my project I have used 8 ports as inputs and 8 ports as output. 690 doesn't have all these ports available, so you will decide how many inputs and how many outputs to use. Remember to set the TrisA; TrisB and TrisC registers accordingly.


Al.