[SOLVED] How to write AT-commands on an MCU?

[seadolphine2000]

at commands pic

Hi everyone,..

I know that this topic might be repeated but I'm really confused.
I have a NOKIA 6610 and I want to connect it with PIC16F877 via serial cable. My only problem is:
How to write the AT-commands in basic or C languages?

For example:
AT+CMGR=2 --> This command will read the sms stored in location 2.

I want to know how to translate this command into basic or C.?

Thanks very very much guys for your help and patience.

 

[eamol]

how to write at commands

If you are using C language for programming, Take a string
e.g.
unsigned char send_data[] = "AT+CMGR=2";

and send this on UART using SBUF, use any loop such as for loop.

and after sending this string you have to send CR
(carriage return ASCII CODE = 0x0d)

and you have to wait for response from modem.

 

[seadolphine2000]

where to write at commands

eamol,..
Thanks very much for your help. I have another question:
What is " SBUF "?

Thanks again for your time.

 

[blastronics]

mcu and 6610

how do you do this in assembly?
does each AT - command has a ascii or binary equivalent?

 

[glenjoy]

sending at commands using mcu

This had been discussed many time here, try to use the search function and you will get many results.

 

[budhy]

pic mcu atcommands

seadolphine2000 wrote:

How to write the AT-commands in basic or C languages?

if your C language stdio library has puts() and putchar() function, and those function are redirected to serial port, you can send AT command like that :

unsigned char send_data[] = "AT+CMGR=2"; 
    puts(send_data); 
    putchar(0x0D);

blastronics wrote :

does each AT - command has a ascii or binary equivalent?

AT command is an ASCII string, it is represented with ASCII code!
You can build that AT command like this :

ReadSMS DB 'AT+CMGR=2',0x0D

how do you do this in assembly?

Write a Serial Port charater output sub-routine, use it to output above ASCII string character by character, after 0x0D is printed stop the loop.

 

[seadolphine2000]

nokia 6610 at commands

Hello all,..

I have another question and hope you can help.

Can I send the command AT+CMGR=2 in ASCII?
I mean, can I send it character by character?
Example:
Soft_Uart_write(64)
Soft_Uart_write(84)
....
so on

where:
Soft_Uart_write is the command that sends the data serially.
64 is the ASCII code of A and 84 is the ASCII code of T.

Thanks very very much guys for all your help, I really appreciate that.

 

[budhy]

soft_uart_write

Yes you can do that. 64 and 'A' has same binary value : 01100100

if Soft_Uart_write() is an C function, Soft_Uart_write(64) and Soft_Uart_write('A') is the same!

 

[VSMVDD]

mcu commands

at commands are string's

write them in strings

make a set of defines and a menu use some buttons to then send the strings

you simply make an array of command strings
DONT send char by char

instead dump the whole string
alternalty wire a keyboard upto the pic and an lcd then youll have a dumb terminal

 

[Kuzito]

at commands mcu

Hi seadolphine2000,

I use this C+ code to call to one number.
I using PIC16F877 and Siemens :

printf("AT");
delay_ms(500);
printf("D+359xxxxxxxxxL;");

"+359" is country code.
"xxxxxxxxxx" is number

Kuzito

 

[seadolphine2000]

pic at commands

Guys,..
Thanks very much for your time and consideration up till now.

I have another problem which is when I connect the phone to the PC and start to send the command using the hyper terminal, I found that all what I typed didn't appear on the hyp trm screen.
I tried all the possible combinations of baud rate, flow control, ASCII settings,... but all gave the same result, Nothing appear.

A friend has 6210 and he tried connecting the phone to the hyp trm and succeeded, he told me that he had installed a driver for the phone cable.

The question is: What driver for the cable?
Do I need to write this driver on the MCU to connect the phone to the MCU?

Thanks very very much all of you.

 

[budhy]

at90s2313 nokia at command

I found that all what I typed didn't appear on the hyp trm screen.

Keep try type in AT <enter>, what is the answer from cell phone?
If the Cellphone answer OK, it mean every thing is OK. At this case you have to type in ATE1<enter>, after that every thing is going right

 

[kishorekhatri]

at commands for k750

i have siemens C55 cell phone,, the AT command work well while connected PC.
the data cable convert RS232 violatage level into TTL/CMOS, data cable have max232 circuit within the port. and it get power from DB-9 PC.

now problem is that if i connect the data cable with micro controller then how can i provide powere to it cause there is only 3 pins in MC (Tx,Rx and GRD),
and i dont know what voltage and from which pins of PC's DB-9 the data cable get the power.

once i connected direct C55 's TX,RX & grd with CELL phone the at commands workd but other day it doesn't work , some body told me that u must use MAX232 is to interface and use data cable.

 

[budhy]

schematic max232cpe mcu

data cable have max232 circuit within the port. and it get power from DB-9 PC.

i dont know what voltage and from which pins of PC's DB-9 the data cable get the power.

You have to supply these voltage to DB-9 connector
pin 7 DB9 (RTS) -9 Volt
pin 4 DB9 (DTR) +9 Volt
pin 5 DB9 (GND)

But be careful that the following pins
pin 2 DB9 (RXD)
pin 3 DB9 (TXD)
has a RS232 Voltage level, that's >+5 Volt as logic level '0' and <-5 Volt as logic level '1', you can't connect this pin to micro controller's TXD pin and RXD pin directly, it may burn out that pins!

once i connected direct C55 's TX,RX & grd with CELL phone the at commands works but other day it doesn't work

Without the above voltage supplies, the data cable doesn't works!

some body told me that u must use MAX232 is to interface and use data cable.

Yes, its true!

Another connection is like this:

 

[seadolphine2000]

view screen siemen c55 with vb6

budhy,..

has a RS232 Voltage level, that's >+5 Volt as logic level '0' and <-5 Volt as logic level '1'

How to supply the Rx,Tx pins with -5 volts from the microcontroller?

Thanks very much guys for your concern.

 

[budhy]

at command pic

How to supply the Rx,Tx pins with -5 volts from the microcontroller?

Please note that <-5 Volt and >+5 Volt is the RS232 Voltage level (at DB-9 pins), it isn't micro controller pins. That voltage is supplied from IC MAX232!

 

[seadolphine2000]

sms controller using pic with ericsson t20

budhy,..
Thanks very much for all your help, but I'm really confused. According to this

Quote:
some body told me that u must use MAX232 is to interface and use data cable.

Yes, its true!

I have to use the MAX232, but according to this:

Quote:
PIC16F84A microcontroller and a Nokia 6210 cellphone. We will also use a Max232

mobile phones usually use inverted TTL RX/TX signals, so max232 is unnecessary

The MAX232 is unnecessary.

I'm really confused.

 

[budhy]

pakistani putchar

Don't confuse, kishorekhatri discuss about connect cellphone to microcontroller thru a dala cable, which has build in 3.8 Volt Logic to RS232 converter.
At this case he need a RS232 to 5 Volt logic converter on the microcontroleer board.

The picture I were attached illustrate direct connection without data cable, at this case max232 is unnecessary

 

[kishorekhatri]

program for sending sms on mcu

MR Budhy wat is ur Yahoo id ?
i wanna discuss u more about my project ...

thanks

 

[Prabakaran]

how to write at commands

Hi
This is Prabakaran , can i have the connection between the Micro controller and Mobile Phone . Can u give the circuit diagram to connect the mobile phone with microcontoller to implement the functionality . This would be useful for my reference.