FBUS initialisation protocol & timing

[James Cheong]

Hi everyone

 

I'm trying to use the Gnokii code to interface a Nokia 5110 to a M16C(Mitsubishi microcontroller) to send SMS. I'm using software delays to generate the 100us delays and I having some trouble with the initialisation process.

Below is the pseudo code of what I've done and a list of 5 questions, hope you can find time to answer them.

: )

 

 

 

for (count = 0; count < 32; count ++) {
    delay_us(100);
    transmit 0x55;    
    }
transmit 0xc1;    

SendStatusRequest();   
delay_us(100);
SendMsg(7, 0x02, connect1);  // Initiate connection 
delay_us(100);
SendMsg(5, 0x02, connect2);
delay_us(100);
SendMsg(7, 0x02, connect3);
delay_us(100);  
SendMsg(4, 0x64, connect4);  // Phone ID request

delay_us(100);   // ???

 

GetNokiaAuth(IMEI, MagicBytes, magic_connect+4);   //270us to execute
SendMsg(45, 0x64, magic_connect);      //180us lag before change in Tx Pin

 

FB61_SendSMSMessage( );     // any delays need???

 

 

1)First of all, do you transmit the end_init_char (0xc1) right after the 32nd 0x55 char??? Or is a 100us delay needed?

 

2)For the SendMsg( ) functions, is a 100us delay between frames very important? Has anyone check with an oscilloscope to ensure that there is 100us delay between each frame? Because I've noticed with my micro, that the processing involved for SendMsg( ) can be quite significant for longer message lengths and I have to tweak the code to ensure 100us delays between frames.

 

3) What is the delay used between the "SendMsg(4, 0x64, connect4)" frame and the "SendMsg(45, 0x64, magic_connect)" ?

My code wouldn't work if a 100us delay there is required because even if I have no delays in after calling SendMsg(4, 0x64, connect4); there is an inherent processing delay caused by GetNokiaAuth( ). 

 

4)According to the protocol, is the first frame u receive from the phone an acknowledgement for the SendStatusRequest( )? Currently, I'm not receiving any frames from the phone at all.

: (

 

5) Is the above pseudo code all that is needed to initialise the link with the 5110? Can I call the FB61_SendSMSMessage( ) right after initialisation is successful???

 

Thanks very much for your time.

 

James

 

 

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