Read status of FT245RL pins - usb

Sorry for my ignorance but I am very new in FTDI chip Linux software development.
I have module based on FT245RL chip, programmed to be 4 port output (relays) and 4 port opto isolated input unit.
I found out in Internet program in C to turn on/off relays connected to outputs D0 to D3. After compiling it works properly. Below draft of this working program:
/* switch4.c
* # gcc -o switch4 switch4.c -L. -lftd2xx -Wl,-rpath,/usr/local/lib
* Usage
* # switch4 [0-15], for example # switch4 1
* */
#include <stdio.h>
#include <stdlib.h>
#include "./ftd2xx.h"
int main(int argc, char *argv[])
{
FT_STATUS ftStatus;
FT_HANDLE ftHandle0;
int parametr;
LPVOID pkod;
DWORD nBufferSize = 0x0001;
DWORD dwBytesWritten;
if(argc > 1) {
sscanf(argv[1], "%d", ¶metr);
}
else {
parametr = 0;
}
FT_SetVIDPID(0x5555,0x0001); // id from lsusb
FT_Open(0,&ftHandle0);
FT_SetBitMode(ftHandle0,15,1);
pkod=&parametr;
ftStatus = FT_Write(ftHandle0,pkod,nBufferSize,&dwBytesWritten);
ftStatus = FT_Close(ftHandle0);
}
My question is. How can I read in the same program, status of D4 to D7 pins, programmed as inputs? I mean about "printf" to stdout the number representing status (zero or one) of input pins (or all input/output pins).
Can anybody help newbie ?
UPDATE-1
This is my program with FT_GetBitMode
// # gcc -o read5 read5.c -L. -lftd2xx -Wl,-rpath,/usr/local/lib
#include <stdio.h>
#include <stdlib.h>
#include "./ftd2xx.h"
int main(int argc, char *argv[])
{
FT_STATUS ftStatus;
FT_HANDLE ftHandle0;
UCHAR BitMode;
FT_SetVIDPID(0x5555,0x0001); // id from lsusb
ftStatus = FT_Open(0,&ftHandle0);
if(ftStatus != FT_OK) {
printf("FT_Open failed");
return;
}
FT_SetBitMode(ftHandle0,15,1);
ftStatus = FT_GetBitMode(ftHandle0, &BitMode);
if (ftStatus == FT_OK) {
printf("BitMode contains - %d",BitMode);
}
else {
printf("FT_GetBitMode FAILED!");
}
ftStatus = FT_Close(ftHandle0);
}
But it returns "FT_GetBitMode FAILED!" instead value of BitMode


FT_GetBitMode returns the instantaneous value of the pins. A single byte will be
returned containing the current values of the pins, both those which are inputs and
those which are outputs.
Source.


Finally I found out whats going wrong. I used incorrect version of ftdi library. The correct version dedicated for x86_64 platform is located here:
Link to FTDI library

Related

I2C communication between PIC32 and LCD

I am trying to communicate with LCD2041 using I2C . I am using PIC32MM curiosity board . I wrote the following code on MP lab code configurator , but the status for I2c communications is stuck on I2C2_MESSAGE_PENDING . I need help on what I might have done wrong or what I am missing .
#include <stdint.h>
#include <string.h>
#include <xc.h>
#include "mcc_generated_files/mcc.h"
//#include "lcd_i2c.h"
#define slave_Adress 0b01010000
void ByteDelay(void){
// Delay between bytes required by LCD2041 spec
DELAY_microseconds(625);
}
void ReadDelay(void){
// Delay between read commands required by LCD2041 spec
DELAY_milliseconds(3);
}
void TransactionDelay(void){
// Delay between transactions required by LCD2041 spec
DELAY_microseconds(375);
}
int main(void)
{
SYSTEM_Initialize();
uint8_t data = 0xFE; // host to tell data are output via I2c
uint8_t lcd_clear_display = 0xA4; // command to clear LCD
TRISBbits.TRISB2 = 1; // set B2 (scl) as input
TRISBbits.TRISB3 = 1; // set B3 (SDA) as input
I2C2_Initialize() ;
I2C2_MESSAGE_STATUS status ;
I2C2_MasterWrite(data, 1 , slave_Adress, &status);
ByteDelay();
if ( status == I2C2_MESSAGE_PENDING) {led_3_SetHigh();}
return 1;
}
The default slave address for the LCD is 0x50

I had a similar error once with an pic18f and mcc. I forgot to activate the global interrups. I don't see a place where you do that in your code.

InterruptAttach fails on am3352x irq number 97 for bank 0B

I am trying to attach an IRQ handler to a gpio bank 0 i.e 0B irq no 97.
At the present moment, my implementation returns with -1. What am I doing wrong? It would be a very simple issue to implement.
#include <stdio.h>
#include <unistd.h>
#include "gpio.h"
#include <sys/neutrino.h>
#include "interrupt.h"
volatile unsigned int gpio0_irq_count;
static const struct sigevent * gpio0_irq_handler (void *gpio, int id){
gpio0_irq_count++;
return NULL;
}
int main(){
int ret;
unsigned long count=0;
ret = InterruptAttach(97, gpio0_irq_handler, NULL,0,_NTO_INTR_FLAGS_TRK_MSK);
printf("%s: Registering handler for irq %d result = %d\n",__func__ , 97, ret);
if (ret)
return -1;
while(1){
printf("%s:[%lu] : gpio0_irq_count = %d\n", __func__, count++, gpio0_irq_count);
sleep(2);
}
}
The erroneous output is:
main: Registering handler for irq 97 result = -1

After much back and forth with QNX, it turns out that a process requesting InterruptAttach() or InterruptAttach_r() needs elevated permissions acquired through
ThreadCtl( _NTO_TCTL_IO, 0 );
Once that is executed the API's work. However, one must still configure the gpio registers to actually fire the interrupt.
GPIO_OE
GPIO_STATUS
GPIO_STATUS_SET
GPIO_CTRL
GPIO_RISINGDETECT

configuration of adafruit ultimate gps from raspberry pi does not work

I connected my ultimate gps breakout to my raspberry pi using the USB to TTL serial cable. Using C code I can easily connect to and read NMEA sentences from the GPS. But when I write configuration commands such as PMTK220 to set the update rate, they are ignored. I should get back a PMTK_ACK reporting success or failure, but it is not forthcoming. The problem also occurs when I use terminal windows. ie. I run:
while (true) do cat -A /dev/ttyUSB0 ; done
in one terminal, and get a stream of $GPGGA, $GPGSA, $GPRMC etc messages. In another terminal I run:
echo "$PMTK220,200*2C\r\n" > /dev/ttyUSB0
The NMEA messages continue but there is no PMTK001 coming back. Any ideas?

Ok, here's some code (inspired by gpsd source) that demonstrates sending a configuration message and getting an acknowledgement:
#define _BSD_SOURCE
#include <stdio.h>
#include <stdarg.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>
#include <semaphore.h>
#include <string.h>
#ifndef CRTSCTS
# ifdef CNEW_RTSCTS
# define CRTSCTS CNEW_RTSCTS
# else
# define CRTSCTS 0
# endif /* CNEW_RTSCTS */
#endif /* !CRTSCTS */
int main (int argc, char **argv) {
int const baudr = B9600, mode = O_RDWR | O_NONBLOCK | O_NOCTTY;
int const fd = open("/dev/ttyUSB0", mode);
assert (fd != -1);
ioctl(fd, (unsigned long)TIOCEXCL);
struct termios ttyOld, ttyNew;
assert(tcgetattr(fd, &ttyOld) != -1);
ttyNew = ttyOld;
ttyNew.c_cflag &= ~(CSIZE | PARENB | PARODD | CRTSCTS | CSTOPB);
ttyNew.c_cflag |= CREAD | CLOCAL | CS8;
ttyNew.c_iflag = ttyNew.c_oflag = 0;
ttyNew.c_lflag = ICANON;
cfsetispeed(&ttyNew, baudr);
cfsetospeed(&ttyNew, baudr);
assert(tcsetattr(fd, TCSANOW, &ttyNew) != -1);
tcflush(fd, TCIOFLUSH);
usleep(200000);
tcflush(fd, TCIOFLUSH);
int const oldfl = fcntl(fd, F_GETFL);
assert (oldfl != -1);
fcntl(fd, F_SETFL, oldfl & ~O_NONBLOCK);
tcdrain(fd);
printf("port opened baudr=%d mode=%d i=%d o=%d c=%d l=%d fl=%d\n", baudr, mode, ttyNew.c_iflag, ttyNew.c_oflag, ttyNew.c_cflag, ttyNew.c_lflag, oldfl);
unsigned char buf[2048];
int count = 0;
while(++count < 20) {
if (count == 4) {
char const *const cmd = "$PMTK220,200*2C\r\n";
int const n = strlen(cmd);
assert(write(fd, cmd, n) == n);
tcdrain(fd);
printf("wrote command %d: %s\n", n, cmd);
}
int const n = read(fd, buf, sizeof(buf));
buf[(n >= sizeof(buf)) ? (sizeof(buf) - 1) : n] = 0;
printf(buf);
}
tcsetattr(fd, TCSANOW, &ttyOld);
close(fd);
}
with results:
pi#pi01 ~/c $ ./test
port opened baudr=13 mode=2306 i=0 o=0 c=3261 l=2 fl=2050
$GPGGA,175748.089,,,,,0,00,,,M,,M,,*71
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,175748.089,V,,,,,0.00,0.00,260715,,,N*43
wrote command 17: $PMTK220,200*2C
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$PMTK001,220,2*31
$GPGGA,175749.089,,,,,0,00,,,M,,M,,*70
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,1,1,01,11,,,31*7A
$GPRMC,175749.089,V,,,,,0.00,0.00,260715,,,N*42
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,175750.089,,,,,0,00,,,M,,M,,*78
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,175750.089,V,,,,,0.00,0.00,260715,,,N*4A
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,175751.089,,,,,0,00,,,M,,M,,*79
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,175751.089,V,,,,,0.00,0.00,260715,,,N*4B
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,175752.089,,,,,0,00,,,M,,M,,*7A
pi#pi01 ~/c $

Handle GPIO in User Space ARM9 Embedded Linux AM1808

I have to interface my GSM module with the AM1808 based on ARM9.
I have assigned all the GPIO pins to the Da850.c as well as mux.h files. I successfully created a uImage and inserted that image in my flash.
I need to handle some of that GPIO from User application.
I know that we can handle the GPIO from the Kerel space but i need to handle from the user space.
As for example I have assigned a GPIO for power key to GSM module. I need to change the pin means (HIGH or LOW) through application.
Ok i have written a following code to access it from the User Space,
#include <stdio.h>
#include <time.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <unistd.h>
#include "GSMpwr.h"
#define BS_GSM_PWR_REGISTER 0x01E26014
#define BS_DCDS_MASK 0x00000004
int fd; // Memory device descriptor
unsigned long *pPWR;
unsigned short GetGSMpwr(void)
{
#if defined __HOST_ARM
unsigned long dcd_value = *pPWR;
return (pwr_value >> 7) & 0x01;
#endif
}
void InitializeGSMpwr(void)
{
#if defined __HOST_ARM
int page_size = getpagesize();
unsigned int MAP_addr;
unsigned int reg_addr;
unsigned char *pTemp; // Pointer to GSMpwr register
/*
* Open memory and get pointer to GSMpwr register in the FPGA
*/
if((fd = open("/dev/mem", O_RDWR | O_SYNC)) < 0)
{
printf("failed to open /dev/mem");
return;
}
else
{
MAP_addr = (BS_GSM_PWR_REGISTER & ~(page_size - 1));
pTemp = (unsigned char *)mmap(NULL, page_size,(PROT_READ | PROT_WRITE),MAP_SHARED,fd,MAP_addr);
if((pTemp == MAP_FAILED) || (pTemp == NULL))
{
printf("failed to map /dev/mem");
return;
}
else
{
printf(“Memory Mapped at Address %p. \n”,pTemp);
}
virt_addr = map_base + (control & MAP_MASK);
reg_addr = (BS_GSM_PWR_REGISTER & (page_size - 1));
pPWR = (unsigned long*)(pTemp + reg_addr);
printf("GSM PWR PIN mapped in Application\n");
}
I can only read that pin through this code, Now i want to use that pin as an output and want to go high and low with the time interval of 3sec.

The easiest way is to utilize GPIO support in sysfs, where you could control all the exported GPIO's. Please have a look at the Linux kernel GPIO documentation, in particular, Sysfs Interface for Userspace part.
After you have enabled GPIO support in sysfs (GPIO_SYSFS), the GPIO control would be as easy as:
Example
GPIO=22
cd /sys/class/gpio
ls
echo $GPIO > /sys/class/gpio/export
ls
Notice on the first ls that gpio22 doesn't exist, but does after you export GPIO 22 to user space.
cd /sys/class/gpio/gpio$GPIO
ls
There are files to set the direction and retrieve the current value.
echo "in" > direction
cat value
You can configure the GPIO for output and set the value as well.
echo "out" > direction
echo 1 > value
Example is taken from here.

I got it please find following code for that,I got the Specific pin address and i have accessed that pin like,
unsigned short GetGSMpwr(void)
{
unsigned long pwr_value = *pPWR;
printf("GSM_PWR:check Start : %ld",pwr_value);
return (pwr_value >> 1) & 0x01;
}
unsigned short SetGSMpwr(void)
{
unsigned long pwr_value = *pPWR;
printf("GSM_PWR:check Start : %ld",pwr_value);
*pPWR = ~((pwr_value >> 1) & 0x01);
}
unsigned short ClrGSMpwr(void)
{
unsigned long pwr_value = *pPWR;
printf("GSM_PWR:check Start : %ld",pwr_value);
*pPWR = 256;
}`

programatic way to find ELF aux header (or envp) in shared library code?

I'm looking for a programatic way to find the powerpc cpu type on Linux. Performing some google searches associated an answer suggesting the mfpvr instruction I found that this is available in the ELF AUX header, and sure enough I can obtain the POWER5 string for the machine I'm running on with the following:
#include <stdio.h>
#include <elf.h>
int main( int argc, char **argv, char **envp )
{
/* walk past all env pointers */
while ( *envp++ != NULL )
;
/* and find ELF auxiliary vectors (if this was an ELF binary) */
#if 0
Elf32_auxv_t * auxv = (Elf32_auxv_t *) envp ;
#else
Elf64_auxv_t * auxv = (Elf64_auxv_t *) envp ;
#endif
char * platform = NULL ;
for ( ; auxv->a_type != AT_NULL ; auxv++ )
{
if ( auxv->a_type == AT_PLATFORM )
{
platform = (char *)auxv->a_un.a_val ;
break;
}
}
if ( platform )
{
printf( "%s\n", platform ) ;
}
return 0 ;
}
In the shared library context where I want to use this info I have no access to envp. Is there an alternate programatic method to find the beginning of the ELF AUX header?

You can get if from /proc/self/auxv file
According to man proc /proc/self/auxv is available since kernel level 2.6.0-test7.
Another option - get some (existing) environment variable - let say HOME,
or PATH, or whatever. Please note that you'll get it's ADDRESS. From here you can go back and find previous env variable, then one before it, etc. After that you can likewise skip all argv arguments. And then you get to the last AUXV entry. Some steps back - and you should be able find your AT_PLATFORM.
EDIT: It looks like glibc now provides a programatic method to get at this info:
glibc-headers-2.17-106: /usr/include/sys/auxv.h : getauxinfo()
Example:
#include <sys/auxv.h>
#include <stdio.h>
int main()
{
unsigned long v = getauxval( AT_PLATFORM ) ;
printf( "%s\n", (char *)v ) ;
return 0 ;
}