On Wed, 2012-09-12 at 16:15 -0500, Ryan Tennill wrote:
> I need to open and monitor LOTS (> 50) of FTDI devices on a single
> computer as serial ports with CBUS GPIO. We're using one of the FT232R's
> CBUS pins as power enable and UART activity for now.
>
> Is there a standard way for opening and controlling multiple devices
> simultaneously and independently? Even when I only create one child
> process and open one device, the call to ftdi_set_bitmode() is sent to
> ALL DEVICES even ones not explicitly opened!
>
> I am using libftdi 0.20 and libusb0.1 which may not be thread-safe...
> http://developer.intra2net.com/mailarchive/html/libftdi/2012/msg00118.html
>
> If libftdi-1.0 / libusb-1.0 thread-safe then I should probably consider
> switching over but I still don't understand why my set_bitmode() goes to
> all attached FT232's...
>
> Pseudocode:
> - ftdi_new()
> - ftdi_init()
> - ftdi_usb_find_all()
> - for all found devices
> - ftdi_usb_open_desc_index(ftdi,DEVICE_VID,DEVICE_PID,NULL,NULL,i)
> - read chipID and get serial from EEPROM
> - ftdi_usb_close(ftdi) after reads
> - fork() and child execl()'s another program to manage UART
> and CBUS after parent exits
> - parent sets process group ID of child to new group shared
> by all children (** this might be a problem too ? **)
> - once all children processes created and running, parent
> cleans up eeprom, ftdi_dev_list, ftdi_deinit, and exits
>
>
> The child process opens devices by serial using the following call:
> ftdi_usb_open_desc(ftdi, DEVICE_VID, DEVICE_PID,NULL,ftdi_serial)
>
>
> --
> libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
> To unsubscribe send a mail to libftdi+unsubscribe@xxxxxxxxxxxxxxxxxxxxxxx
>
Here's a modified version of the bitbang example that eliminates the
possible issues from fork()'ing. If anyone has multiple devices of the
same type can they give this a shot?
//CODE
/***************************************************************************
main.c - description
-------------------
begin : Mon Apr 7 12:05:22 CEST 2003
copyright : (C) 2003,2008 by Intra2net AG
email : opensource@xxxxxxxxxxxxx
***************************************************************************/
/***************************************************************************
*
*
* This program is free software; you can redistribute it and/or
modify *
* it under the terms of the GNU General Public License version 2 as
*
* published by the Free Software Foundation.
*
*
*
***************************************************************************/
//Modified by Ryan Tennill @ Distant Focus Corp 2012
//Goal: test CBUS I/O control using libFTDI with FT232R and Ubuntu 10.04
//Note: Requires CBUS configured as I/O in EEPROM
//Note: Requires RXD, TXD inverted in EEPROM
//Note: Driving CBUS HIGH=ON, LOW=OFF
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "ftdi.h"
//my constants
#define MCCM_ON 0xFF
#define MCCM_OFF 0xF0
//ftdi defaults
#define DEFAULT_PID 0x6001
#define DEFAULT_VID 0x0403
//easily change initial device VID and PID
#define DEVICE_VID DEFAULT_VID
#define DEVICE_PID DEFAULT_PID
//#define DEVICE_PID 0x6015 //FT230X
//debug defines
#define PRINT_RAW_EEPROM 0
#define PRINT_EEPROM_STRUCT 1
void cleanup(struct ftdi_context *ftdi){
printf("FTDI close: %d\n", ftdi_usb_close(ftdi));
if(ftdi != NULL) ftdi_deinit(ftdi);
printf("\n");
}
int main(int argc, char *argv[]) {
struct ftdi_context *ftdi;
unsigned char mychar;
int f = 0;
if ((ftdi = ftdi_new()) == 0) {
printf("ftdi_new failed\n");
return EXIT_FAILURE;
}
if (ftdi_usb_open(ftdi, DEVICE_VID, DEVICE_PID)) {
printf("Unable to find FTDI devices under given vendor/product
id: 0x%X/0x%X\n", \
DEVICE_VID, DEVICE_PID);
printf("Retrying with default FTDI id.\n");
if (ftdi_usb_open(ftdi, DEFAULT_VID, DEFAULT_PID)) {
printf("Error: %s\n", ftdi->error_str);
exit (-1);
}else{
printf("device opened with default VID, PID\n");
}
}else{
printf("sucessfully opened device with VID, PID: 0x%04X | 0x%04X
\n",DEVICE_VID,DEVICE_PID);
}
mychar = MCCM_OFF;
printf("driving LOW\n");
if ((f=ftdi_set_bitmode(ftdi, mychar, BITMODE_CBUS)<0)) {
printf("write failed for 0x%x, error %d (%s)\n",mychar,f,
ftdi_get_error_string(ftdi));
}
printf("set_bitmode returned: %d\n",f);
sleep(3);
mychar = MCCM_ON;
printf("driving HIGH\n");
if ((f=ftdi_set_bitmode(ftdi, mychar, BITMODE_CBUS)<0)) {
printf("write failed for 0x%x, error %d (%s)\n",mychar,f,
ftdi_get_error_string(ftdi));
}
printf("set_bitmode returned: %d\n",f);
sleep(3);
mychar = MCCM_OFF;
printf("driving LOW\n");
if ((f=ftdi_set_bitmode(ftdi, mychar, BITMODE_CBUS)<0)) {
printf("write failed for 0x%x, error %d (%s)\n",mychar,f,
ftdi_get_error_string(ftdi));
}
printf("set_bitmode returned: %d\n",f);
printf("test completed\n");
cleanup(ftdi);
return 0;
}
--
libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
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