FTDI 2232 H Mini Module SPI to USB converter Clock Problem

[adip]

Hi

So I am trying to send data from SPI bus (from PIC MCU) to USB. I was using the MPSSE protocol and was able to do it .

The problem i am facing is that to run the program successfully , we have to restart the PIC MCU. The reason behind this is as soon as the program gets executed , the CLK goes to high, where as in the operation it starts from low. So everytime the program starts the MCU which is monitoring continuously misreads the intialisation.

Also i cant find the command to make it operate from high instead of going to low in the beginning.

I am using MPSSE . ftd2xx.h , lib to operate on the ftdi.

Thanks in advance.

 

[bobcat1]

Re: FTDI 2232 H Mini Module SPI to USB converter Clock Probl

HI

Look at the PIC mcu DS for the SPI set up registers it should have a clock or data reversal bit


All the best

Bobi

The microcontroller specialist

 

[adip]

Re: FTDI 2232 H Mini Module SPI to USB converter Clock Probl

Hi

But the problem is with the ftdi chip and its clock mode. I cant seem to make it start from high in the operation too.. that way it wont go to low and MCU will misread it.

Sorry, I dont understand how the bit reversal register is going to help.

Thanks

 

[millwood]

I have to say that it is (near?) impossible to understand what you are saying.

I would suggest that you put your code up, tell us what you expect to say and what you say.

help us so we can help you.

 

[adip]

Re: FTDI 2232 H Mini Module SPI to USB converter Clock Probl

i apologize if i am not able to make myself clear.

The problem is the free or ideal state of the clock is high (b/w ftdi and MCU).But as soon as i intialise my program the clock immediatly goes to low and then starts the clock cycle.Here is the code for ftdi 2232h chip. I am trying to intialise MPSSE and recieve 6 bytes (its similar to there application note AN_135 ) .

All I want is to not stop MCU all the time , if i stop the ftdi chip.

/*
To build you must include ftd2xx.dll, ftd2xx.lib, ftd2xx.h in your source directory.
*/

#include "stdafx.h"
#include <windows.h>
#include <stdio.h>
#include "ftd2xx.h"

FT_STATUS init_usb(FT_HANDLE ftHandle);
FT_STATUS init_mpsse(FT_HANDLE ftHandle);

FT_STATUS write_start(FT_HANDLE ftHandle, int len);
FT_STATUS write_data(FT_HANDLE ftHandle, unsigned char *buff, DWORD len, DWORD *wLen);
FT_STATUS write_stop(FT_HANDLE ftHandle);

FT_STATUS read_data(FT_HANDLE ftHandle, unsigned char *buff, DWORD len, DWORD *wLen);

int main(int argc, char *argv[])
{
FT_STATUS ftStatus;
FT_HANDLE ftHandle;
DWORD len;
DWORD wLen;
unsigned char buff[20 + 2];

int i;

ftStatus = FT_Open(0, &ftHandle);
if (ftStatus != FT_OK)
printf("FT_Open Port A failed\n");

printf("Init USB and MPSSE\n");
ftStatus = init_usb(ftHandle);


#if 1
ftStatus = init_mpsse(ftHandle);

strcpy((char *)&buff[0], "Hello World!"); // String to output on SDO
printf("Write Data\n");
len = strlen("Hello World");

ftStatus = write_start(ftHandle, len);
for (i = 0; i < 2; i++)
{
ftStatus = write_data(ftHandle, buff, len, &wLen);
//sleep(1);
}
ftStatus = write_stop(ftHandle);

// sleep(2);
#endif

#if 1
printf("Init MPSSE\n");
ftStatus = init_mpsse(ftHandle);
printf("Read\n");
len = 5;
ftStatus = read_data(ftHandle, buff, len, &wLen);
printf("No bytes read %d\n", (int)wLen);

for (i = 0; i < wLen; i++)
printf("0x%x ", buff);
printf("\n");
#endif

ftStatus = FT_SetBitMode(ftHandle, 0x00, 0x00);
ftStatus = FT_Purge(ftHandle, FT_PURGE_TX | FT_PURGE_RX);
ftStatus = FT_ResetDevice(ftHandle);

FT_Close(ftHandle);

return 0;
}



FT_STATUS init_usb(FT_HANDLE ftHandle)
{
FT_STATUS ftStatus;
PFT_EVENT_HANDLER eh;
DWORD InOutTransferSize = 64 * 1024;
unsigned char event_error = 0x00;

/* Reset Device and Purge USB Buffers */
ftStatus = FT_ResetDevice(ftHandle);

/* Set USB Buffer to 64K */
ftStatus = FT_SetUSBParameters(ftHandle, InOutTransferSize, InOutTransferSize);
if (ftStatus != FT_OK)
printf("USB Setup Failed\n");

ftStatus = FT_Purge(ftHandle, FT_PURGE_TX | FT_PURGE_RX);

ftStatus = FT_SetEventNotification(ftHandle, 0, (PVOID) &eh );
if (ftStatus != FT_OK)
printf("Set Event Notification Failed\n");

ftStatus = FT_SetChars(ftHandle, event_error, 0, event_error, 0);
if (ftStatus != FT_OK)
printf("Set Chars Failed\n");

/* Set Timeouts */
ftStatus = FT_SetTimeouts(ftHandle, 0, 5000);
if (ftStatus != FT_OK)
printf("Set Timeout Failed\n");

ftStatus = FT_SetLatencyTimer(ftHandle, 16);
if (ftStatus != FT_OK)
printf("Set Latency Timeout Failed\n");

ftStatus = FT_Purge(ftHandle, FT_PURGE_TX | FT_PURGE_RX);
if (ftStatus != FT_OK)
printf("Purge Buffers Failed\n");

// usleep(100000);

return(ftStatus);
}


FT_STATUS init_mpsse(FT_HANDLE ftHandle)
{
FT_STATUS ftStatus;
DWORD wBytes;
DWORD nBytes;
unsigned char mpsee_cmd[16];

/* Reset MPSEE Mode */
ftStatus = FT_SetBitMode(ftHandle, 0x00, 0x00);

/* Set MPSEE Mode */
ftStatus = FT_SetBitMode(ftHandle, 0x00, 0x02);
if (ftStatus != FT_OK) {
printf("Failed to set MPSEE mode\n");
}

/* Set 8 Low Pins Directions and Output */
mpsee_cmd[0] = 0x80;
mpsee_cmd[1] = 0x00; //default is 0x00
mpsee_cmd[2] = 0xEB;
nBytes = 3;
ftStatus = FT_Write(ftHandle, mpsee_cmd, nBytes, &wBytes);
if(ftStatus != FT_OK)
printf("Set Low Pins Failed\n");

/* Set 4 High Pins Directions and Output */
mpsee_cmd[0] = 0x82;
mpsee_cmd[1] = 0x00;
mpsee_cmd[2] = 0x0F;
nBytes = 3;
ftStatus = FT_Write(ftHandle, mpsee_cmd, nBytes, &wBytes);
if(ftStatus != FT_OK)
printf("Set High Pins Failed\n");

/* Set Clock to 1.5 Mhz */
mpsee_cmd[0] = 0x86;
mpsee_cmd[1] = 0x03; // default is 0x03
mpsee_cmd[2] = 0x02;
nBytes = 3;
ftStatus = FT_Write(ftHandle, mpsee_cmd, nBytes, &wBytes);
if(ftStatus != FT_OK)
printf("Set Clock Failed\n");

/* Disconnnect Loopback */
mpsee_cmd[0] = 0x85;
nBytes = 1;
ftStatus = FT_Write(ftHandle, mpsee_cmd, nBytes, &wBytes);
if(ftStatus != FT_OK)
printf("Set Loopback Failed\n");
//usleep(100000);

return(ftStatus);
}


FT_STATUS write_start(FT_HANDLE ftHandle, int len)
{
FT_STATUS ftStatus;
DWORD wBytes;
unsigned char mpsee_cmd[8];

/* Set 8 Low Pins Directions and Output */
mpsee_cmd[0] = 0x80; // Set Data Bits Low Byte; default is 0x80
mpsee_cmd[1] = 0x00; // Initial value assigned to pins; default is 0x00
mpsee_cmd[2] = 0xFB; // Determines which pins are input or output.
// 0xFB maps to 1111 1011 (AD7-AD0)

mpsee_cmd[3] = 0x11; // 0x11 clocks bytes on falling (-ve) edge (default)
mpsee_cmd[4] = (unsigned char)(((len - 1) & 0xff00) >> 8);
mpsee_cmd[5] = (unsigned char)((len - 1) & 0x00ff);

ftStatus = FT_Write(ftHandle, mpsee_cmd, 6, &wBytes);

return(ftStatus);
}

FT_STATUS write_stop(FT_HANDLE ftHandle)
{
FT_STATUS ftStatus;
DWORD wBytes;
unsigned char mpsee_cmd[8];

/* Set 8 Low Pins Directions and Output */
mpsee_cmd[0] = 0x80;
mpsee_cmd[1] = 0xFF; // default is 0xFF
mpsee_cmd[2] = 0xFB;

ftStatus = FT_Write(ftHandle, mpsee_cmd, 3, &wBytes);

return(ftStatus);
}

FT_STATUS write_data(FT_HANDLE ftHandle, unsigned char *buff, DWORD len, DWORD *wLen)
{
FT_STATUS ftStatus;

ftStatus = FT_Write(ftHandle, buff, len, wLen);

return(ftStatus);
}


FT_STATUS read_data(FT_HANDLE ftHandle, unsigned char *buff, DWORD len, DWORD *wLen)
{
FT_STATUS ftStatus;
unsigned char mpsee_cmd[16];
DWORD wBytes;
int i;

/* Set 8 Low Pins Directions and Output */
mpsee_cmd[0] = 0x80;
mpsee_cmd[1] = 0x00; // default is 0x00
mpsee_cmd[2] = 0xFB;

ftStatus = FT_Write(ftHandle, mpsee_cmd, 3, &wBytes);
if(ftStatus != FT_OK)
printf("Set Low Pins Failed\n");

*wLen = 0;

#if 1
for (i = 0; i < len; i++)
{
/* Read from device without write */
mpsee_cmd[0] = 0x20;
mpsee_cmd[1] = 0;
mpsee_cmd[2] = 0;

ftStatus = FT_Write(ftHandle, mpsee_cmd, 3, &wBytes);
if(ftStatus != FT_OK)
printf("Read from Device Failed\n");

//usleep(20000);
/* Move Data to buffer */
mpsee_cmd[0] = 0x87;
ftStatus = FT_Write(ftHandle, mpsee_cmd, 1, &wBytes);
if(ftStatus != FT_OK)
printf("Data Move Failed\n");
}
#else

/* Read from device without write */
mpsee_cmd[0] = 0x20;
mpsee_cmd[1] = (unsigned char)((len - 1) & 0x00ff);
mpsee_cmd[2] = (unsigned char)(((len - 1) & 0xff00) >> 8);

ftStatus = FT_Write(ftHandle, mpsee_cmd, 3, &wBytes);
if(ftStatus != FT_OK)
printf("Read from Device Failed\n");

/* Move Data to buffer */
mpsee_cmd[0] = 0x87;
ftStatus = FT_Write(ftHandle, mpsee_cmd, 1, &wBytes);
if(ftStatus != FT_OK)
printf("Data Move Failed\n");
#endif

/* Read Data from USB Buffer */
ftStatus = FT_GetQueueStatus(ftHandle, wLen);
printf("wLen = %d\n", (int)*wLen);

if (*wLen > 0)
ftStatus = FT_Read(ftHandle, buff, *wLen, &wBytes);

if(ftStatus != FT_OK)
printf("Read Failed\n");

return(ftStatus);
}


Thanks

 

[millwood]

did you observe the right data going to the chip?

 

[adip]

Yes, I saw the data going in from the PIC is correct (I checked it using a CRO), So data recieved by the chip is correct.

Does anybody know how to use the FT_Purge() function what is the Umask in that?

Thanks