hyperterminal siemens c25 problem

[ttn1]

hi to all , im new here and im from spain but my english its not perfect.

im here because im turning crazy with a project.i want to comunicate a pic with a mobile phone , exactly siemens c25, but first i want to see how it works trough hyperterminal or some serial console.

i connected siemens c25 to max233 , and my surprise , the cellphone was blocked and i used a tool to unlock , everithing perfect, the cell now is unlocked , wich confirms that rs232 and max233 works correctly.

then i try with hyperterminal in configuration 9600,8,n,1 none, and i have no response. but in 57600, 8 , n , 1 none i have some response from the phone but not works at all.
when i connect the phone to hyperteminal and power on, shows me two squares and "OK" but if write some AT comand nothing happens.

i hope someone can helpme

thanks in advance

 

[cdh7]

Hi,

Is it possible that your phone has hardware handshaking but only the Tx and Rx lines are connected? Maybe you will have to wire up the flow control pins as well.

Regards,
Chris

 

[ttn1]

hi cdh7 ! thanks for reply!

i only connect tx rx and gnd , but in pinouts of c25 there 2 pinout with , what i believe are handshaking pins

https://pinouts.ru/CellularPhones-P-W/siemens_c25_s25_pinout.shtml exactly pins 7 and 8.

but i dont know where connect these pinouts, max233? directly to rs232? please if you know tell me.

thanks in advance.

Added after 4 minutes:

i found this document but i dont understand at all but i think its very interesting

https://www.electronicspoint.com/fui-siemens-c35-and-c45-data-cable-connector-t23652.html

 

[cdh7]

Hi ttn1,

Yep, it sounds like those are handshaking pins, although the reference designs out there don't seem to use them, so no idea if they help.

Just connect them to the second set of TTL pins on your MAX233, and wire the RS-232 pins to the appropriate pins on your serial connector (CTS and DCD, according to the link you gave).

Regards,
Chris

 

[Imyke]

Hello!

I managed to fix the problem? What caused the error?

Thanks!

Hi!
Imre