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CR95H UART

JOHN SOLOMON
Associate
Posted on April 09, 2018 at 13:34

Hi, i am using CR95H RFID CLICK module with raspberry pi3.I am using UART for communication.

I connected,

   SSI_1   =>   GND

   SSI_0   =>   GND

   TX        =>    RX

   RX        =>   TX

   VIN       =>   3.3X

   GND     =>    GND.

 for waking up i am sending 0x00 and then i send echo cmd but i didnt any response.can any one help me out i new to these modules

#include<bcm2835.h>

#include <string.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <termios.h>

#include <sys/ioctl.h>

#include<stdio.h>

uint8_t buf2[11],buf1;

void send_data(uint8_t buf1)

{

int fd;

fd = open('/dev/ttyS0', O_RDWR, O_NOCTTY);

fd = write(fd, &buf1, 11);

if (fd == -1) {

printf('failed to write the file');

}

usleep(100000);

close(fd);

}

void recv_data()

{

int fd;

fd = open('/dev/ttyS0', O_RDWR, O_NOCTTY);

if (fd == -1) {

printf('failed to open the file');

}

fd = read(fd, buf2, 17);

if(buf2[0]==0x55)

{

printf('ECHO');

}

printf('%x', buf2);

close(fd);

}

int main(void)

{

bcm2835_init();

delay(10);

send_data(0x00);

usleep(10);

for(int i=0;i<10;i++)

{

send_data(0x55);

recv_data();

delay(50);

}

}
1 ACCEPTED SOLUTION

Accepted Solutions
Posted on April 23, 2018 at 11:44

Hello John,

For your information the default baud rate set on the CR95HF is 57600 bps.

Can you please tell which baud rate is programmed for the UART communication.

Are you sure that you will comply with the specs for your negative pulse sent on IRQIN/RX pin.

Regards

PB

View solution in original post

3 REPLIES 3
Andrew Neil
Chief II
Posted on April 09, 2018 at 16:22

i am using CR95H

That's not an STM32 - so why didyou post this in the STM32 forum?

EDIT

Moved by moderator to  

https://community.st.com/community/st25-nfcrfid-tags-and-readers

 > 

https://community.st.com/community/st25-nfcrfid-tags-and-readers/content?filterID=contentstatus%5Bpublished%5D~objecttype~objecttype%5Bthread%5D

Andrew Neil
Chief II
Posted on April 09, 2018 at 16:44

... with raspberry pi3. I am using UART for communication ... 

So are you familiar with using the Raspberry Pi serial comms in general?

Posted on April 23, 2018 at 11:44

Hello John,

For your information the default baud rate set on the CR95HF is 57600 bps.

Can you please tell which baud rate is programmed for the UART communication.

Are you sure that you will comply with the specs for your negative pulse sent on IRQIN/RX pin.

Regards

PB