GPIO problem

[Paleantrop]

Hello,

I am trying to write a character to a specific IO pin but no success . So, I have the following pieces of code (I mention that I have modified the BSP lib in order to have access to this specific pins) :

const uint_32 output_set[] = {    TX_PIN,     TX_ENABLE,       GPIO_LIST_END         };output = fopen("gpio:write", (char_ptr) &output_set);if (output){  SetOutput();}else      printf("Error\n");.......

the SetOutput function : 

void SetOutput(void){   static const uint_32 TxPin[] = {  TX_PIN,  GPIO_LIST_END      };       static const uint_32 TxEnable[] = {  TX_ENABLE,  GPIO_LIST_END     };         ioctl(output, 1, (pointer) &TxPin);    ioctl(output, 1, (pointer) &TxEnable);}

Debugging the program , I've seen that it is a problem with fopen function (I think). As you can see in the printscreen attached : it reaches that breakpoint and never steps out.

Can anyone have an idea ? What I am doing wrong.. ?

Thanks

[boogy]

Are you using magic numbers?

This works for me.

When I send a character I start a timer after setting the enable pin. The timer times out and resets the pin for me.

#define GPIO_IOCTL_WRITE_LOG1       _IO(IO_TYPE_GPIO,0x02)  /* Set pins on output port */
#define GPIO_IOCTL_WRITE_LOG0       _IO(IO_TYPE_GPIO,0x03)  /* Clear (set to 0) pins on output port */

 GPIO_PIN_STRUCT ch1_ps[] =     {  CH1_TX_ENABLE,  GPIO_LIST_END }; FILE_PTR ch1_enable_fh;......//initializationch1_enable_fh = fopen("gpio:write", ch1_ps );//use in the serial send routine_mqx_int    unc1_putc(uchar c){ _mqx_int err; err = 0; if(socket_flag && sockfd != NULL) {  err = fputc(c,sockfd); } else if(application_list[HOST_APP] !=0) {  ioctl(ch1_enable_fh, GPIO_IOCTL_WRITE_LOG1, NULL);  err = fputc(c,ch1_fh);  uart1_timer = (40000  / uart1_baud) +1;  while(uart1_timer)   _time_delay(10); } return (err);}//timer times out if(uart1_timer)  if(! -- uart1_timer)  {   ioctl(ch1_enable_fh, GPIO_IOCTL_WRITE_LOG0, NULL);     }

[Paleantrop · Accepted solution]

Thanks for your reply!

It seemed to be a hardware problem (not correctly connected to the I/O pins).

Right now, I am trying to send a char using RS-485 (4 wires). So, I have Rx, Tx, RxEnable, TxEnable. Maybe you can give a hint regarding this topic because I think I missed something (based on the fact I am a beginner with MQX).

I have the defines :

#define TxPin     BSP_TX#define RxPin     BSP_RX#define Tx_Enable BSP_TX_ENABLE#define Rx_Enable BSP_RX_ENABLE

 Initialize function :

boolean InitializeIO(void) {    const uint_32 output_set[] = {        TxPin    | GPIO_PIN_STATUS_0,        Tx_Enable | GPIO_PIN_STATUS_0,        Rx_Enable | GPIO_PIN_STATUS_0,        GPIO_LIST_END    };        const uint_32 input_set[] = {        RxPin,        GPIO_LIST_END    };    /* Open and set port as output  */    output_port = fopen("gpio:write", (char_ptr) output_set);    /* Open and set port as input to read value from Rx pin*/    input_port = fopen("gpio:read", (char_ptr) input_set);        if (output_port && input_port)        return (input_port!=NULL) && (output_port!=NULL);         else     return 0;}

 Then I am trying to setup the outputs (for transmitting - RxEnable 1 and TxEnable 1 :

void SetOutput(int signal)
{
   uint_32  set_value=0;
  
   static const uint_32 Send[] = {
    TxPin,
    GPIO_LIST_END
   };
   static const uint_32 SendEnable[] = {
    Tx_Enable,
    GPIO_LIST_END
   };
  
   static const uint_32 ReceiveEnable[] = {
    Rx_Enable,
    GPIO_LIST_END
   };
  
   if(output_port)
   {
           switch(signal)
           {
               case 1: ioctl(output_port, GPIO_IOCTL_WRITE_LOG1, (pointer) &Send);
              
               case 2:
               {
              
                   ioctl(output_port, GPIO_IOCTL_WRITE_LOG1, (pointer) &SendEnable);
                   ioctl(output_port, GPIO_IOCTL_WRITE_LOG1, (pointer) &ReceiveEnable);   
               }
           }
   }
   
  
}

 And the trying to send the character :

int SendChar(uchar c){ _mqx_int error=0;  SetOutput(2); ioctl(output_port, GPIO_IOCTL_WRITE_LOG1, NULL); error = fputc(c,output_port); _time_delay(100); return error;}

Any hint ? What I am doing wrong ?

Many thanks