// Reads from a device using I2C. The command character is written first and then len bytes are read from the device.
void ReadI2C(char slaveAddress, char cmd, int len, char *data)
{
I2CHW_bWriteBytes(slaveAddress, &cmd, 1, I2CHW_NoStop); // Write cmd byte
while (!(I2CHW_bReadI2CStatus() & I2CHW_WR_COMPLETE)); // Wait until ACK is received
I2CHW_ClrWrStatus(); // Clear write bit
I2CHW_fReadBytes(slaveAddress, data, len, I2CHW_CompleteXfer); // Read len bytes into data
while (!(I2CHW_bReadI2CStatus() & I2CHW_RD_COMPLETE)); // Wait until reading is done
I2CHW_ClrRdStatus(); // Clear read bit
}
void main(void){
M8C_EnableGInt;
M8C_EnableIntMask(INT_MSK0, INT_MSK0_GPIO);
I2CHW_Start();
I2CHW_EnableSlave();
I2CHW_EnableInt();
AMUX4_Start();
PGA_1_Start(PGA_1_HIGHPOWER);
ADCINC_Start(ADCINC_HIGHPOWER);
TX8_Start(TX8_PARITY_NONE);
LED_DBG_ON();
TX8_CPutString("I2C slave addr:0x");
TX8_PutSHexByte(I2CHW_SLAVE_ADDR);
TX8_PutCRLF();
LED_DBG_OFF();
for(;;){
// I2C
i2c_status = I2CHW_bReadI2CStatus();
if(i2c_status & I2CHW_WR_COMPLETE){ // master->slave
I2CHW_ClrWrStatus();
I2CHW_InitWrite(buf_rx, BUF_SIZE);
}
if(i2c_status & I2CHW_RD_COMPLETE){ // slave->master
I2CHW_ClrRdStatus();
I2CHW_InitRamRead(buf_tx, BUF_SIZE);
}
// ADC
for(ad_pin = 0; ad_pin < 4; ad_pin++){
ad = get_adc(ad_pin);
weights[ad_pin] = ad;
TX8_PutChar(ad_pin+'0');
TX8_CPutString(":");
TX8_PutString(intToStr(ad,buf));
TX8_PutCRLF();
}
buf_tx[0] = 'a';
buf_tx[1] = 'b';
buf_tx[2] = 'c';
buf_tx[3] = 'd';
}
}
void main(void)
{
M8C_EnableGInt ; // Uncomment this line to enable Global Interrupts
// Start the UART(with no parity), and Counter16
UART_Start(UART_PARITY_NONE);
// clock for moving serial
Counter16_Start();
// Start I2CHW
I2CHW_Start();
I2CHW_EnableMstr();
I2CHW_EnableInt();
// This is the command usage string
UART_CPutString("########################## I2C External SRAM ########################\r\n\
# W # XX T [Data]\r\n\
# W - Write command\r\n\
# # - Group Address (0 - 7)\r\n\
# XX - Memory Location in hex (00 - FF)\r\n\
# T - Data Type, either A for ASCII or H for Hexadecimal\r\n\
# Data - Either ASCII string or Hexadecimal separates by spaces\r\n\
#\t\t\tA - Mary had a little lamb\r\n\
#\t\t\tH - 01 FF A0 0F D8 C3\r\n\
#\r\n\
# R # XX T NN\r\n\
# R - Read command\r\n\
# # - Group Address (0 - 7)\r\n\
# XX - Memory Location in hex (00 - FF)\r\n\
# T - Data Type, either A for ASCII or H for Hexadecimal\r\n\
# NN - Number of bytes to read in hexadecimal\r\n\
#####################################################################\r\n");
while (1)
{
char *cmd;
char *params;
char slaveAddress = 0x50; // 010100000 R/W shifted to front
GetLine(buf, 79); // Retrieves a line with a maximum length of 70 characters and put it in buf.
memset(data, 0x00, 256); // Initialize all the set {data} to NULL bytes
cmd = Lowercase(cstrtok(buf, " ")); // Get the first word from the entered string and lowercase it.
if (strlen(cmd) == 1 && cmd[0] == 'w') // If the command is one letter and it is w, then write command
{
int groupAddress; // only 1 and 2 actually go to SRAM
int memLoc;
char dataType;
int len;
params = cstrtok(0x00, " "); // 0x00 indicates it will continue from last cstrtok command and get next word. This gets the next parameter
// csscanf if used to parse the string into values such as hexadecimal or integers
// It returns the number of parameters it parsed which should be one
// If the length of the params is not right or it does not parse the right amount, it returns an error
// %d gets an integer, this is the groupAddress
if (strlen(params) != 1 || csscanf(params, "%d", &groupAddress) != 1) goto error;
// %x gets a hexadecimal value, this can read capital or lowercase letters, this is the memory location
params = cstrtok(0x00, " ");
if (strlen(params) != 2 || csscanf(params, "%x", &memLoc) != 1) goto error;
// %c gets a character, the data type character
params = cstrtok(0x00, " ");
if (strlen(params) != 1 || csscanf(params, "%c", &dataType) != 1) goto error;
// This reads the rest of the string and stores it in params.
// If the length is zero or if cstrtok returns 0, this means that there was no valid string/hex entered
params = cstrtok(0x00, "\0");
if (strlen(params) == 0 || params == 0x00) goto error; // They did all the params but didn't write anything
dataType = tolower(dataType); // Lowercase the data type
if (groupAddress < 0 || groupAddress > 7)
goto error; // groupAddress was not in range
data[0] = memLoc; // First byte needs to be the memory location according to PCF8570 datasheet
slaveAddress |= groupAddress; // ORs the group 2 address to the group 1 address to get slaveAddress
if (dataType == 'a') // If the data type is ASCII
{
strcpy((data + 1), params); // Copy the string from params and put it right after the data[0] byte
len = strlen((data + 1)) + 1; // len is the number of bytes to write, it is the length of the string and then +1 because of the memLoc byte
// Cant just do strlen(data) because data[0] could be 0x00 and it would return 0 as the string length
}
else if (dataType == 'h') // If the data type is hex
{
// Take ASCII encoded hex data params and put it after data[0], returns number of bytes converted
if ((len = HexConversion(params, (data + 1))) == -1)
goto error;
len++; // Add one to the length because of the memLoc byte at data[0]
}
else
goto error;
I2CHW_bWriteBytes(slaveAddress, data, len, I2CHW_CompleteXfer); // Write len bytes from data
while (!(I2CHW_bReadI2CStatus() & I2CHW_WR_COMPLETE)); // Wait while it is writing
I2CHW_ClrWrStatus(); // Clear the write bit
csprintf(data, "%x bytes were written", len); // csprintf takes the string and substitutes %x for len, puts into data str
UART_PutString(data); // Print the string to UART
UART_PutCRLF();
}
else if (strlen(cmd) == 1 && cmd[0] == 'r') // If the command is one letter and it is r, then read command
{
int groupAddress;
int memLoc;
char dataType;
int numBytes;
char hexStr[4];
int i;
// csscanf if used to parse the string into values such as hexadecimal or integers
// It returns the number of parameters it parsed which should be one
// If the length of the params is not right or it does not parse the right amount, it returns an error
// %d gets an integer, this is the groupAddress
params = cstrtok(0x00, " ");
if (strlen(params) != 1 || csscanf(params, "%d", &groupAddress) != 1) goto error;
// %x gets a hexadecimal value, this can read capital or lowercase letters, this is the memory location
params = cstrtok(0x00, " ");
if (strlen(params) != 2 || csscanf(params, "%x", &memLoc) != 1) goto error;
// %c gets a character, the data type character
params = cstrtok(0x00, " ");
if (strlen(params) != 1 || csscanf(params, "%c", &dataType) != 1) goto error;
// %x gets a hexadecimal value, number of bytes to read
params = cstrtok(0x00, " ");
if (strlen(params) != 2 || csscanf(params, "%x", &numBytes) != 1) goto error;
// If there is any data after the number of bytes, then the format is invalid and it should return an error
if (cstrtok(0x00, " ") != 0x00) goto error;
dataType = tolower(dataType); // Lowercase the data type
if (groupAddress < 0 || groupAddress > 7)
goto error; // groupAddress was not in range
data[0] = memLoc; // First byte needs to be the memory location according to PCF8570 datasheet
slaveAddress |= groupAddress; // ORs the group 2 address to the group 1 address to get slaveAddress
I2CHW_bWriteBytes(slaveAddress, data, 1, I2CHW_NoStop); // Write one byte to the RAM, the slaveAddress so it knows who were talking to
while (!(I2CHW_bReadI2CStatus() & I2CHW_WR_COMPLETE)); // Wait while it is writing
I2CHW_ClrWrStatus(); // Clear the write bit
I2CHW_fReadBytes(slaveAddress, data, numBytes, I2CHW_CompleteXfer); // Read numBytes from the RAM, put it in data
while(!(I2CHW_bReadI2CStatus() & I2CHW_RD_COMPLETE)); // Wait while it is reading
I2CHW_ClrRdStatus(); // Clear the read bit
if (dataType == 'a') // If the data type is ASCII
{
for (i = 0; i < numBytes; ++i) // Loop through each byte
UART_PutChar(data[i]); // Put the character in PuTTy
UART_PutCRLF();
}
else if (dataType == 'h') // If the data type is Hex
{
for (i = 0; i < numBytes; ++i) // Loop through each byte
{
csprintf(hexStr, "%X ", data[i]); // csprintf prints into hexStr a hexadecimal with a space
UART_PutString(hexStr); // Print hexStr
}
UART_PutCRLF();
}
else
goto error;
}
else
goto error;
continue; // This is so that the error is skipped when everything goes right
error: // This outputs an invalid format message and continues on to read another line
UART_CPutString("Invalid format entered. Valid formats are:\r\n\tW [GroupAddress] [MemoryLocation] [h|a] Hex/ASCII\r\n\tR [GroupAddress] [MemoryLocation] [h|a] [NumBytes]\r\n");
}
}
