joc_06

this project is a lot easier than you might think..

all you need to do is master the usrt on the pic ie get it to send and receive exact commands to the pc. then all you have to do is a direct connection from pic's rx and tx pins to mbile and share gnds and guess what you are done.

Now the hardest part here is testing what the uart receives because it will receive a different no. of bytes for different commands and thats a total bitch. Im using a circular buffer and maybe malloc to create dynamic array that grows according to <cr> position.

Any more q's just ask but note i havnt used pics in a while but 8051's z8 and avr so be patient

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hollywood_aka_ace

I have already finished the interfacing between the cellphone and the PIC
My problem now is how will i program my controller according to what i want. I have very little knowledge in programming stuffs.
My project is a free-call unlocker. the door would only open for certain numbers calling on the cell phone. Then it will automatically be locked again 20 seconds after the call ended. a keypad is connected in order to add and delete contacts numbers that could open the door. but before you could add or remove a number you will be ask to enter a password. if the password entered is incorrect for three consecutive tries. an alarm will be triggered. thats pratically what my project do. i hope you could help me program PIC16F84.

thanks a lot.

joc_06

You need to go to etsi.com and download some pdf's on gsm standards for at command sets. These are big and there are many, also hard to understand so get cracking...

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Noggin

I have a 370 page manual for GSM cellular modem commands. Took forever to print out and punch holes in it.

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KaJuan

Sir I have a question with regards to how the PIC sends and receives in full duplex mode. In a full duplex RS232, will the sending and receving of data happen at the same time? If so how will the PIC handle this since it is only capable of doing once task either by receving or trasmitting. I also have a problem with how the PIC will receive the data replied by the cell phone after you sent the cellphone a certain command. The no. of bytes the PIC will receive is dependent ont ehkind of command the or data teh cellphoen will sned back to the PIC. How will you solve this, my first concept is through the use of arrays. How will you do it? Could you send me a code snipet or code example of it?

KaJuan

Sir I dont know how full duplex works. All I know is that there is a separate line for TX and another for RX and the last is for gnd. MY question is will there be a time by which the sending and receving of data is done at the same time?

joc_06

why use full duplex??

It is useful when io pins are a serious issue but a fair few phones dont have provision for it like older ericssons etc.

My advice to you, as i give to all, is to check the website/cd of the micro you are using. The application notes released are the absolute best way to get into the thing and uart is often a major topic...

for more help you'll have to tell me more specifics, like language, micro, phone etc...

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KaJuan

The reason why I am using full duplex is that the FBUS cable I am using to connect the phone to my cell phone works in full duplex mode.

csaba911

:shock:
:lol:
And I tough I'm beginner!!

Steve

joc_06

You need to do more research. full duplex = mbus, half duplex = fbus (this one is generally acceped to be better option as mbus echoes everything)

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nenayd

my project is similar to your project. Silent Security System Sending SMS-alert. I used old ericsson a1018s for the communication and pic16f84a for the processor. In a long period of debugging and hacking the protocol it was now smoothly working. You can search for this gsm model for your project.


p.s. i can provide you some actual tutorials and programming contact me to this no 09173080656.

carlodie

Hi, Somebody can give me information or FBUS MBUS commands????

terka

Hi

You FBUS cable mybe can set to MBUS

Try it

MEHLULI

I dont know whether you can help me but from the look of things YES!
My project is also similar. I call the landline (whether home or office) and then toggle on or off the appliances. When a call is made, that is, when ringback tone my system decodes the DTMF signal to BCD then it is demuxed to the flip flops that do the toggling on and off of the appliance connected through relays. Now, I thought I could improve by interfacing a cellphone instead of a landline which is fixed, so as to use it for vehicle security. Now I don't know how I can interface a cellphone, just a simple Nokia 5110 to the whole system. Also, I'm trying to incoporate security features by the PIC16F84 for password to access the system.

PLEASE HELP!
P.S. I AM A FINAL YEAR STUDENT DOING APPLIED PHYSICS!

motion

With a hardware UART in a PIC16F627, there is more than enough time to send and receive at the same time. At 9600 baud, the PIC waits more than 1 msec to send/receive a byte of data. In 1msec, the PIC running at 4Mhz can execute 1000 program instructions, while the hardware UART is sending/receiving data.

With a software UART, you have to service the serial port approximately every 100usec @9600baud. There is not much spare CPU time with a 4Mhz PIC to do full duplex.

However, even if the serial connection is full duplex, the cell phone might not transmitting and receiving at the same time. Or the bytes echoed from the cell phone can be ignored while sending commands to it and so you might get away with a software UART.

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