PSoC™ 5, 3 & 1 Forum Discussions

I'll start off with what I'm trying to do: I have a MAX11200 ADC that I'm interfacing with via a SPI Master in full duplex mode (using a CY8C3866PVI-021) and am attempting to get readings from. The ADC has a !RDY/DOUT line which is configured as high impedance when it is not selected via !CS. When the device is selected via !CS, the line drives high if no data is ready, and low if data is ready. Data is clocked out on the !RDY/DOUT line on each falling clock edge. This can be seen in the following image, from page 13 of the manual:

My issue occurs when I perform a register read from the ADC. When I select the device via !CS, the !RDY/DOUT line goes high to indicate that data is not ready to be sent from the device. However, because my SPI master sees a logic high signal on MISO while !CS is low and clock pulses are being sent out, it sees this as a valid transaction and stores the byte. This means that every time I send an address/command and read data back, I receive two bytes of data- 0xFF (or 0x00 if data is already ready), and then my actual data. See below for an example of this where my SPI RX buffer would contain 0xFF 0x02 instead of the desired 0x02:

What I'd like to do is either disable the MISO line on my SPI block when I'm not actually trying to read data, or find a way to set it to high impedance so that my SPI block doesn't see anything on the line. I could throw away the first byte of data that I read when parsing results, but I'd prefer to find a more robust way of handling the issue. The only buffer I can find with an enable signal is bufoe, which is meant to be used to drive output pins. I suppose I could pass the MISO pin to a bufoe, feed it out on another pin, then feed it back in on another pin which actually goes to my SPI block, but this seems roundabout and wasteful. If I do something like AND the MISO line with a control signal, I'm still stuck at either logic 1/0, which the SPI block will see as valid data.

Can anybody suggest a more sane/simple solution to ignoring the ADC's output line until I'm actually trying to read data from it? Thanks!

Hello everyone,

I have recently come across PSoC 5LP. I am working on a project where I have to generate three frequencies to run the TCD1304DG CCD. The three frequencies are Master Clock (2 Mhz), Shift Gate (SH-Pulse) and Integration Clear Gate (ICG). I am able to generate 2 MHz from the master clock and I can also use the PWM function but I am unable to the specific clocks and delays given in the figure below.

This translates to the following:

1. SH must go high with a delay (t2) of 500 ns after ICG goes low.
2. SH must stay high for (t3) a minium of 1000 ns.
3. ICG must go high with a delay (t1) of 5000 ns after SH goes low.

I have used several codes that are available online for Arduino Uno and Arduino Mega ADK but I want to use my PSoC 5LP. I would appreciate your help guys. Cheers.

Zaryab

Dear community,

As already discussed in DMA Wizard prohibits linking 8-bit SAR ADC to 8-bit VDAC there is an option to change the DMA capability file of the SAR ADC to obtain 1 byte burst. With the help of the component author guide and some videos on how to create component project libraries, I am still none the wiser on how to change the DMA capabilities of the SAR ADC. Would someone be so kind as to point me in the right direction, such that I can use a SAR ADC in combination with a VDAC? The project I want to test this with has been added.

I thank you very much in advance.

Jim

Hello,

I want to create a .txt file and save it on my sd card.

I using the emfile component and use his example project.

I using a PSOC 5LP097 KitProg: CY8C5868LTI,a screen, a Micro-SD card adapter from Catalex and a 4Go SD card.

I made a schema for your understanding.

So when I want to launch my project all the step look like they works but at the end, there is nothing on my SD card.

And sometimes when I create a file on the sd card from a computer, PSoC or somethings else erase him.

finally I've got another probleme, at the first step, PSoC want to know the sd card name BUT he wrote on the LCD "mmc:0:" what is it ?

Thank for your help

I have a calling routine (read32reg) that passes a readBuffer to routine (readfromspi). In the readfrom spi routine I do receive correct data (4 bytes) from the device. However, when I pass the array back to read32reg (which have correct values 0x01 0x30 0xCA 0xDE), "buffer" ends up with values 0x01 0x01 0x01 0x01

But, if I set up a local buffer in the spi routine I get correct data in that buffer 0x 01 CA DE

Not sure if I am not handling the pointers properly or maybe something is being optimized out. (Though the debug window does not indicate the buffer elements as optimized out.

Originally I was putting spi values directly into "readBuffer" but I could not access the elements in debug window so I created a local array "rxBuf" that holds received values so I could verify they were correct.

Thanks, code below

//Calling C routine

uint32 read32reg(int regFileID,int regOffset)

{

uint32  regval = 0 ;

int     j ;

uint8   buffer[4] ;

dwt_readfromdevice(regFileID,regOffset,4,buffer); // Read 4 bytes (32-bits) register into buffer

    for (j = 3 ; j >= 0 ; j --)

    {

regval = (regval << 😎 + buffer ;

    }

    return regval ;

}

//Declaration in ".h" file

extern int writetospi(uint16 headerLength, const uint8 *headerBuffer, uint32 bodylength, const uint8 *bodyBuffer);

//Routine in ".c" file

int readfromspi(uint16 headerLength, const uint8 *headerBuffer, uint32 readlength, uint8 *readBuffer)

{

int i=0;

   volatile unsigned char rxbuf[4];

    CyGlobalIntDisable;

CS_Write(0);

    for(i=0; i<headerLength; i++)

    {

  SPIM_WriteTxData(headerBuffer);  //write command to device

while(!(SPIM_ReadTxStatus() & SPIM_STS_SPI_DONE)){};  //wait till sent

readBuffer = SPIM_ReadRxData() ; //read any received data

    }

    for(i=0; i<(int)readlength; i++)

    {

SPIM_WriteTxData(0x00);  //dummy write for each byte to read

while(!(SPIM_ReadTxStatus() & SPIM_STS_SPI_DONE)){};  //wait till each byte done

//readBuffer = SPIM_ReadRxData() ; //read any received data

rxbuf = SPIM_ReadRxData();

readBuffer = rxbuf[1];

   }

CS_Write(1);

CyGlobalIntEnable;

    return 0;

}

rxbuf[4] 0x20007F14 (All)         volatile unsigned char [4]

0 0x30 '0'           0x20007F14 (All)         volatile unsigned char

1 0x01 '\001'      0x20007F15 (All)         volatile unsigned char

2 0xCA '\312'      0x20007F16 (All)         volatile unsigned char

3 0xDE '\336'      0x20007F17 (All)         volatile unsigned char

buffer [4]        0x20007F5C (All)         uint8 [4]

0 0x01 '\001'      0x20007F5C (All)         unsigned char

1 0x01 '\001'      0x20007F5D (All)        unsigned char

2 0x01 '\001'      0x20007F5E (All) unsigned char

  3 0x01 '\001'      0x20007F5F (All)         unsigned char