ok so my project consists of using an msp430f5659 and a PN532 communicating over I2C. its working for the most part but i need some advice. i started off a example program which has now been wildly altered to fit my project. my first question is now that i have over seven data packs is there a way to have less pointers say not a pointer for each array. as it stands i have a function for transmitting and reciving and it would be extremely convenient if i say could put the data pack in the function like "transmit(0x02, 0xAA);" and the function takes care of the preamble as well as the data length byte the check sum frame identifier and data check sum and post-amble automatically. so fare i have just been making an array of each with all the information. like this...
unsigned char *PTxData; // Pointer to TX data
volatile unsigned char TXByteCtr;
const unsigned char TxData[] = // get firmwear version
{
0x00,
0x00,
0xFF,
0x02,
0xFE,
0xD4,
0x02,
0x2A,
0x00
};
then when i want to transmit i do something like this.
x=0;
Transmit(); // Get Firmewar version
which calls my function
void Transmit(void){
unsigned int i;
for(i=0;i<10;i++); // Delay required between transaction
if(x == 1)
{
PTx2Data = (unsigned char *)Tx2Data; // TX array start address
// Place breakpoint here to see each // transmit operation.
TXByteCtr = sizeof Tx2Data; // Load TX byte counter
}
else if(x == 2)
{
PTx3Data = (unsigned char *)Tx3Data; // TX array start address
// Place breakpoint here to see each // transmit operation.
TXByteCtr = sizeof Tx3Data; // Load TX byte counter
}
else if(x == 3)
{
PTx4Data = (unsigned char *)Tx4Data; // TX array start address
// Place breakpoint here to see each // transmit operation.
TXByteCtr = sizeof Tx4Data; // Load TX byte counter
}
else if(x == 4)
{
PTx5Data = (unsigned char *)Tx5Data; // TX array start address
// Place breakpoint here to see each // transmit operation.
TXByteCtr = sizeof Tx5Data; // Load TX byte counter
}
else
{
PTxData = (unsigned char *)TxData; // TX array start address
// Place breakpoint here to see each // transmit operation.
TXByteCtr = sizeof TxData; // Load TX byte counter
}
UCB0CTL1 |= UCTXSTT | UCTR; // I2C TX, start condition
__bis_SR_register(LPM0_bits | GIE); // Enter LPM0, enable interrupts
__no_operation(); // Remain in LPM0 until all data
// is TX'd
while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
}
and the isr
case 12: // Vector 12: TXIFG
if (TXByteCtr) // Check TX byte counter
{
if(x == 1)
{
UCB0TXBUF = *PTx2Data++; // Load TX buffer
TXByteCtr--; // Decrement TX byte counter
}
else if(x == 2)
{
UCB0TXBUF = *PTx3Data++; // Load TX buffer with int passive mode
TXByteCtr--; // Decrement TX byte counter
}
else if(x == 3)
{
UCB0TXBUF = *PTx4Data++; // Load TX buffer
TXByteCtr--; // Decrement TX byte counter
}
else if(x == 4)
{
UCB0TXBUF = *PTx5Data++; // Load TX buffer
TXByteCtr--;
}
else
{
UCB0TXBUF = *PTxData++; // Load TX buffer
TXByteCtr--; // Decrement TX byte counter
}
}
else
{
UCB0CTL1 |= UCTXSTP; // I2C stop condition
UCB0IFG &= ~UCTXIFG; // Clear USCI_B0 TX int flag
__bic_SR_register_on_exit(LPM0_bits); // Exit LPM0
}
default: break;
}
this is just the case in the isr that deals with transmitting......
now u can see as i make entire data packs each with its own pointer and changing a value of x before each transmit function is called now that can be overly complicated as well as take up more memory. i also use the same rx buffer and i haven't found out yet if each time i receive information if it starts back at 0. this will be impotent now because i will need to check incoming data in order to know what to send the pn532 as well as when it sends information about a card its reading it will say have 4 bytes in a pre determined spot of the incoming data pack that are to be repeated back in my next data pack to verify i wanted that card or as say an authorization thing. any advice about all of this would be much appreciated. maybe a suggestion about how to change my transmit function to just put that value of to tell it to send the data pack i want or better yet the data for the data pack bearing in mind it would have to fill in the check sum and all that as well as possibly filling in 4 bytes that was from a data pack just received. also what is the best way to check the rxbuffer in terms of setting the hex value of a variable to say rxbuffer[5] whatever it may be. i used....
volatile unsigned char c;
c = RxBuffer[9];
and im not sure it has always worked nor am i sure if my rx buffer resets to zero everytime it recives data or if it tacks it onto the end of the last data fed to the array my rx buffer is being used like this...
unsigned char *PRxData; // Pointer to RX data
volatile unsigned char RXByteCtr;
volatile unsigned char RxBuffer[100]; // Allocate 100 byte of RAM
-- this is to set the byte ctr to what im expecting to recive
RXByteCtr = 32; // Bytes to get
Receive();
--this is my receive function
void Receive(void){
unsigned int i;
for(i=0;i<10;i++); // Delay required between transaction
PRxData = (unsigned char *)RxBuffer; // Start of RX buffer
// RXByteCtr = 7; // Load RX byte counter (moved to outside function due to change as needed)
UCB0CTL1 |= UCTXSTT; // I2C start condition
__bis_SR_register(LPM0_bits | GIE); // Enter LPM0, enable interrupts
__no_operation(); // Remain in LPM0 until all data
// is RX'd
while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
}
---and the part of the isr that deals with receving.
case 10: // Vector 10: RXIFG
// RXByteCtr--; // Decrement RX byte counter (changed due to being skipped)
if (RXByteCtr)
{
RXByteCtr--; // Decrement RX byte counter ****change
*PRxData++ = UCB0RXBUF; // Move RX data to address PRxData
if(RXByteCtr == 1) // Only one byte left?
{
UCB0CTL1 |= UCTXSTP; // Generate I2C stop condition
__bic_SR_register_on_exit(LPM0_bits); // Exit active CPU
}
}
else
{
// *PRxData = UCB0RXBUF; // Move final RX data to PRxData
// __bic_SR_register_on_exit(LPM0_bits); // Exit active CPU
}
break;
please let me know if theres anything i can do or say the syntax (if you will) of having the receive function load the bite counter to where all i have to do is put Receive(32); and it will receive 32 bytes. also with all my data packets iv had to create assuming theres not way to have to data set ups made for me by code can i use a .h file for alot of this so my main is a little less busy? any help would be greatly appreciated keep in mined my code works up tell i want to check my received data array for some reason or i need to automatically change a data pack of mine to match 4 bites of what was received. thats where im stuck. thank you for any help and sorry this is so long.
