2010-08-02 02:49:13 GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92000
Hello world,
I want to use a GPRS modem through UART1 of the BF537.
Can anybody help me out or give me the clues to start on this?
I tried to get information of establishing PPP connection through the GPRS modem to GPRS network from the following link.
www.vpx.nu/dokuwiki/doku.php?id=gprs_ppp
But i found the link was dead.
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2010-08-02 03:41:41 Re: GPRS modem connection for BF537
Sonic Zhang (CHINA)
Message: 92040
Did you succeed on a Linux host PC with your GPRS modem? The steps should be the same.
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2010-08-03 06:10:10 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92105
Yup, I was able to do a successful GPRS connection using a GPRS modem on my host linux PC.
I made sure the following files were present
/etc/ppp/peers/gprs-setup
/etc/ppp/peers/chat/gprs-connect
/etc/ppp/options
I made sure of the content of the files as below
Content of gprs-connect file
ABORT BUSY'
ABORT 'NO CARRIER'
ABORT 'ERROR'
'' AT
OK AT+CMEE=1
OK AT+CGDCONT=1,"IP","portalnmms"
#OK AT+CGDCONT=1,"IP","rcomnet"
OK ATD*99***1#
CONNECT ''
Content of gprs-setup file
/dev/ttyUSB0
9600
crtscts
defaultroute
usepeerdns
lcp-echo-failure 0
lcp-echo-interval 0
proxyarp
ipcp-accept-remote
nodetach
debug
local
noipdefault
file /etc/ppp/options
connect "/usr/sbin/chat -v -f /etc/ppp/peers/chat/gprs-connect"
Content of /options file
lock
In the command terminal I executed the following command to make GPRS connection
sudo pppd call gprs-setup
I was successful in making the connection.
What modifications should i make in uclinux to use GPRS modem through UART1 of the BF537?
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2010-08-03 14:22:51 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92120
so enable UART1 in your kernel config and change the ppp settings to point to the Blackfin serial device
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2010-08-04 03:33:52 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92146
So instead of using the line
/dev/ttyUSB0
should I use
/dev/ttyBF1?
When I made a GPRS connection on my host linux PC (Fedora 8), I had to manually copy the file resolv.conf from the path /etc/ppp to /etc.
When I tried GPRS connection on Obuntu 10.04. It was automatically updated.
What is the procedure in uclinux?
Is there a command to know whether a PPP connnection was successful, so that in that case I can manually configure the resolv.conf file?
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2010-08-04 04:06:02 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92148
there is no automatic procedure for managing /etc/resolv.conf. it is up to you to manage the file. use a symlink if you dont want to modify the file at all.
review the ppp config files to see if there are existing hooks for you to leverage.
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2010-08-05 06:33:37 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92176
I tried to make a GPRS connection using a GPRS modem through PPPD.
I copied all the required settings as above.
when i gave the command pppd call gprs-setup
I got the response as
Connect script failed
Is there anything which i have missed?
I am using BF537 EZkit. Do i need to switch on or off any switches?
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2010-08-05 11:16:29 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92181
what version of software exactly are you using ? if 2009R1.1 isnt working, you might have to grab updates from the 2009R1.1 svn branch for ppp.
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2010-08-06 02:02:15 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92197
Hello Mike,
Can you please tell me how to update the PPP version from the svn?
Since new to linux world, any guidelines would help me !!!
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2010-08-06 02:05:57 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92198
docs.blackfin.uclinux.org/doku.php?id=developing_with_blackfin_live_sources
you will want to use the 2009R1 branch of the uclinux-dist so you dont need to rebuild the toolchain
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2010-08-06 06:27:03 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92221
Hello Mike
Sorry if i am bugging.
I had manually downloaded the following uclinux distribution and the toolchain from the release links.
uClinux-dist-2009R1.1-RC4.tar.bz2
blackfin-toolchain-09r1.1-2.i386.tar.bz2
blackfin-toolchain-elf-gcc-4.1-09r1.1-2.i386.tar.bz2
blackfin-toolchain-uclibc-full-09r1-10.i386.tar.bz2
I had not used the svn.
Probably I guess I should be using the branches.
What version should i use? Branch or trunk?
How to verify what i downloaded manually was a branch or trunk?
If I use the command svn update,will it result in stable release?
Since you said I need to update the PPP in 2009R1.1RC4, is there any way so that i can just update only the PPP?
Or i need to update the entire uclinux distribution?
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2010-08-06 10:09:16 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92225
i already told you to use the branch
svn lets you check out as much or as little as you want
blackfin.uclinux.org/gf/project/uclinux-dist/scmsvn/branches/2009R1/user/pppd/
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2010-08-09 09:12:15 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92262
Hello Mike,
As you said,I gave this command in the terminal,
svn checkout svn://blackfin.uclinux.org/uclinux-dist//branches/2009R1/user/pppd
The downloaded folder was copied in the uClinux-dist/user.
I gave the make clean instruction and made sure that the following files were present
uClinux-dist/romfs/etc/ppp/peers/gprs-setup
uClinux-dist/romfs/etc/ppp/peers/chat/gprs-connect
At this point I compiled and I ran the pppd,but still got the message connect script failed.
I ran a loopback test to confirm that the UART 1 interface is working properly.
Also the modem too works fine.
In the /var/log path, the following was the log file generated
Feb 18 11:11:57 blackfin syslog.info syslogd started: BusyBox v1.13.4
Feb 18 11:11:57 blackfin user.notice kernel: klogd started: BusyBox v1.13.4 (2010-08-09 18:04:38 IST)
Feb 18 11:11:57 blackfin user.notice kernel: Linux version 2.6.28.10-ADI-2009R1.1 (tcoe@tcoe-laptop) (gcc version 4.1.2 (ADI svn)) #95 Mon Aug 9 18:22:35 IS0
Feb 18 11:11:57 blackfin user.info kernel: bootconsole [early_shadow0] enabled
Feb 18 11:11:57 blackfin user.info kernel: Board Memory: 64MB
Feb 18 11:11:57 blackfin user.info kernel: Kernel Managed Memory: 64MB
Feb 18 11:11:57 blackfin user.info kernel: Memory map:
Feb 18 11:11:57 blackfin user.info kernel: fixedcode = 0x00000400-0x00000490
Feb 18 11:11:57 blackfin user.info kernel: text = 0x00001000-0x000f3290
Feb 18 11:11:57 blackfin user.info kernel: rodata = 0x000f3290-0x00142e04
Feb 18 11:11:57 blackfin user.info kernel: bss = 0x00143000-0x00154738
Feb 18 11:11:57 blackfin user.info kernel: data = 0x00154738-0x00166000
Feb 18 11:11:57 blackfin user.info kernel: stack = 0x00164000-0x00166000
Feb 18 11:11:57 blackfin user.info kernel: init = 0x00166000-0x00773000
Feb 18 11:11:57 blackfin user.info kernel: available = 0x00773000-0x03eff000
Feb 18 11:11:57 blackfin user.info kernel: DMA Zone = 0x03f00000-0x04000000
Feb 18 11:11:57 blackfin user.info kernel: Hardware Trace Active and Enabled
Feb 18 11:11:57 blackfin user.info kernel: Boot Mode: 0
Feb 18 11:11:57 blackfin user.info kernel: Blackfin support (C) 2004-2009 Analog Devices, Inc.
Feb 18 11:11:57 blackfin user.info kernel: Compiled for ADSP-BF537 Rev 0.3
Feb 18 11:11:57 blackfin user.info kernel: Blackfin Linux support by blackfin.uclinux.org/
Feb 18 11:11:57 blackfin user.info kernel: Processor Speed: 500 MHz core clock and 125 MHz System Clock
Feb 18 11:11:57 blackfin user.debug kernel: boot memmap: 0000000000773000 - 0000000003eff000 (usable)
Feb 18 11:11:57 blackfin user.debug kernel: On node 0 totalpages: 16127
Feb 18 11:11:57 blackfin user.debug kernel: free_area_init_node: node 0, pgdat 001616e4, node_mem_map 00775000
Feb 18 11:11:57 blackfin user.debug kernel: DMA zone: 126 pages used for memmap
Feb 18 11:11:57 blackfin user.debug kernel: DMA zone: 0 pages reserved
Feb 18 11:11:57 blackfin user.debug kernel: DMA zone: 16001 pages, LIFO batch:3
Feb 18 11:11:57 blackfin user.debug kernel: Normal zone: 0 pages used for memmap
Feb 18 11:11:57 blackfin user.debug kernel: Movable zone: 0 pages used for memmap
Feb 18 11:11:57 blackfin user.info kernel: NOMPU: setting up cplb tables
Feb 18 11:11:57 blackfin user.info kernel: Instruction Cache Enabled for CPU0
Feb 18 11:11:57 blackfin user.info kernel: Data Cache Enabled for CPU0 (write-back)
Feb 18 11:11:57 blackfin user.warn kernel: Built 1 zonelists in Zone order, mobility grouping off. Total pages: 16001
Feb 18 11:11:57 blackfin user.notice kernel: Kernel command line:
Feb 18 11:11:57 blackfin user.info kernel: Configuring Blackfin Priority Driven Interrupts
Feb 18 11:11:57 blackfin user.warn kernel: PID hash table entries: 256 (order: 8, 1024 bytes)
Feb 18 11:11:57 blackfin user.info kernel: console [ttyBF0] enabled, bootconsole disabled
Feb 18 11:11:57 blackfin user.info kernel: Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Feb 18 11:11:57 blackfin user.info kernel: Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Feb 18 11:11:57 blackfin user.debug kernel: Kernel managed physical pages: 16127
Feb 18 11:11:57 blackfin user.info kernel: Memory available: 56312k/65536k RAM, (6196k init code, 968k kernel code, 460k data, 1024k dma, 572k reserved)
Feb 18 11:11:57 blackfin user.info kernel: Calibrating delay loop... 997.37 BogoMIPS (lpj=1994752)
Feb 18 11:11:57 blackfin user.info kernel: Security Framework initialized
Feb 18 11:11:57 blackfin user.warn kernel: Mount-cache hash table entries: 512
Feb 18 11:11:57 blackfin user.info kernel: Blackfin Scratchpad data SRAM: 4 KB
Feb 18 11:11:57 blackfin user.info kernel: Blackfin L1 Data A SRAM: 16 KB (15 KB free)
Feb 18 11:11:57 blackfin user.info kernel: Blackfin L1 Data B SRAM: 16 KB (16 KB free)
Feb 18 11:11:57 blackfin user.info kernel: Blackfin L1 Instruction SRAM: 48 KB (37 KB free)
Feb 18 11:11:57 blackfin user.info kernel: net_namespace: 288 bytes
Feb 18 11:11:57 blackfin user.info kernel: NET: Registered protocol family 16
Feb 18 11:11:57 blackfin user.info kernel: Blackfin DMA Controller
Feb 18 11:11:57 blackfin user.info kernel: stamp_init(): registering device resources
Feb 18 11:11:57 blackfin user.info kernel: NET: Registered protocol family 2
Feb 18 11:11:57 blackfin user.info kernel: IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
Feb 18 11:11:57 blackfin user.info kernel: TCP established hash table entries: 2048 (order: 2, 16384 bytes)
Feb 18 11:11:57 blackfin user.info kernel: TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
Feb 18 11:11:57 blackfin user.info kernel: TCP: Hash tables configured (established 2048 bind 2048)
Feb 18 11:11:57 blackfin user.info kernel: TCP reno registered
Feb 18 11:11:57 blackfin user.info kernel: NET: Registered protocol family 1
Feb 18 11:11:57 blackfin user.debug kernel: Setting up Blackfin MMR debugfs
Feb 18 11:11:57 blackfin user.info kernel: msgmni has been set to 109
Feb 18 11:11:57 blackfin user.info kernel: io scheduler noop registered
Feb 18 11:11:57 blackfin user.info kernel: io scheduler anticipatory registered (default)
Feb 18 11:11:59 blackfin user.info kernel: PHY: 0:01 - Link is Up - 100/Full
Feb 18 11:12:09 blackfin daemon.notice pppd[165]: pppd 2.4.4 started by root, uid 0
Feb 18 11:12:09 blackfin local2.info chat[167]: abort on (BUSY)
Feb 18 11:12:09 blackfin local2.info chat[167]: abort on (NO CARRIER)
Feb 18 11:12:09 blackfin local2.info chat[167]: abort on (ERROR)
Feb 18 11:12:09 blackfin local2.info chat[167]: abort on (RING)
Feb 18 11:12:09 blackfin local2.info chat[167]: send (AT^M)
Feb 18 11:12:09 blackfin local2.info chat[167]: expect (OK)
Feb 18 11:12:54 blackfin local2.info chat[167]: alarm
Feb 18 11:12:54 blackfin local2.info chat[167]: Failed
Feb 18 11:12:54 blackfin user.err syslog: Connect script failed
Feb 18 11:12:54 blackfin user.info syslog: Exit.
Feb 18 11:18:45 blackfin user.info kernel: PHY: 0:01 - Link is Down
Feb 18 11:18:51 blackfin daemon.notice pppd[170]: pppd 2.4.4 started by root, uid 0
Feb 18 11:18:51 blackfin local2.info chat[172]: abort on (BUSY)
Feb 18 11:18:51 blackfin local2.info chat[172]: abort on (NO CARRIER)
Feb 18 11:18:51 blackfin local2.info chat[172]: abort on (ERROR)
Feb 18 11:18:51 blackfin local2.info chat[172]: abort on (RING)
Feb 18 11:18:51 blackfin local2.info chat[172]: send (AT^M)
Feb 18 11:18:51 blackfin local2.info chat[172]: expect (OK)
Feb 18 11:19:36 blackfin local2.info chat[172]: alarm
Feb 18 11:19:36 blackfin local2.info chat[172]: Failed
Feb 18 11:19:36 blackfin user.err syslog: Connect script failed
Feb 18 11:19:36 blackfin user.info syslog: Exit.
Can i know where am i going wrong?
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2010-08-10 01:41:11 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92267
what exactly does your pppd config files look like ?
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2010-08-10 10:20:00 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92288
gprs-setup,gprs-connect and options are the pppd config files i am using
The following is the content of the gprs-setup file in the path /etc/ppp/peers
/dev/ttyBF1
9600
crtscts
defaultroute
usepeerdns
lcp-echo-failure 0
lcp-echo-interval 0
proxyarp
ipcp-accept-remote
nodetach
debug
local
noipdefault
file /etc/ppp/options
connect "/usr/sbin/chat -v -f /etc/ppp/peers/chat/gprs-connect"
The following is the content of the gprs-connect file in the path /etc/ppp/peers/chat
ABORT 'BUSY'
ABORT 'NO CARRIER'
ABORT 'ERROR'
ABORT 'RING'
'' AT
OK AT+CMEE=1
OK AT+CGDCONT=1,"IP","portalnmms"
#OK AT+CGDCONT=1,"IP","rcomnet"
OK ATD*99***1#
CONNECT ''
The following is the content of the options file in the path /etc/ppp
lock
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2010-08-10 15:40:16 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92296
have you actually enabled ctsrts support in the kernel ? the BF537 has no ctsrts support in harware and must be emulated via GPIOs which you must properly configure.
how exactly are you connecting the modem to UART1 ? did you make a little adapter board to plug into ?
have you tried talking to the modem directly from the Blackfin board to see if it works ? you can use picocom to simplify the process.
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2010-08-11 08:34:43 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92320
As per the schematics of the BF537 EZKIT board, the CTS and RTS signal are connected to PF6 and PF4.
For UART 0,I see the following pin configuration were used in the kernel menu configuration.
[*] Enable UART0 hardware flow control
(23) UART0 CTS pin
(22) UART0 RTS pin
I am not able to figure out what pin number i need to assign for the
UART1 CTS pin
UART1 RTS pin
In the schematics,
the PF6(UART1 CTS) and PF4 (UART1 RTS) corresponds to K2 and L4 pins.
the PG6(UART0 CTS) and PG7(UART0 RTS) corresponds to E1 and E2 pins
Not able to understand, on what basis the GPIO pins for RTS and CTS are assigned for UART0.
How to map the CTS and RTS pins for UART 1?
Yup, a small driver board is made to connect the UART.
I have tried using the picocom for testing the modem, but not able to get any results.
I was not able to close the Picocom application nor was i able to give AT commands.
When I used picocom in my PC, the modem connection had no trouble.
I also tried to run the following code.The loopback test went on well but the modem testing I didnt get any result
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
//#define LOOP_BACK
#define MODEM_TEST
int main()
{
int uart1_fd=0,i;
char data_out;
char data_in;
char tx_data[]="HELLO,GOOD MORNING";
char commands[]="AT\r\n";
char rx_buf[100];
char ok_message[]="OK\n";
char nok_message[]="NOT OK\n";
int error_cnt=0;
int rx_inx=0;
int rx_byte_cnt=0;
char buffer[255];
char *bufptr;
int nbytes;
int tries;
struct termios new_options;
struct termios cur_options;
struct termios old_options;
uart1_fd = open("/dev/ttyBF1",O_RDWR | O_NOCTTY | O_NDELAY);
if (uart1_fd == -1)
{
fprintf(stderr,"Unable to open UART 1 - %s\n",strerror(errno));
}
tcgetattr(uart1_fd, &cur_options);
old_options = cur_options;
new_options = cur_options;
// fcntl(uart1_fd, F_SETFL, 0);
fcntl(uart1_fd, F_SETFL, FNDELAY);
cfsetispeed(&new_options, B9600);
cfsetospeed(&new_options, B9600);
new_options.c_cflag |= (CLOCAL | CREAD);
new_options.c_cflag &= ~PARENB;
new_options.c_cflag &= ~CSTOPB;
new_options.c_cflag &= ~CSIZE;
new_options.c_cflag |= CS8;
new_options.c_cflag &= ~CRTSCTS;
new_options.c_lflag &= ~(ICANON | ECHO | ISIG);
new_options.c_lflag &= ~OPOST;
tcsetattr(uart1_fd, TCSAFLUSH, &new_options);
usleep(20000);
#ifdef MODEM_TEST
printf("STARTING MODEM TESTING.......");
if(write(uart1_fd, "AT\r", 3)==3);
{
printf("\nCOMMAND SENT....\n");
bufptr = buffer;
usleep(900000);
while(rx_byte_cnt < 3)
{
nbytes = read(uart1_fd, bufptr, 254);
if(buffer[rx_inx]!=0)
{
data_in=buffer[rx_inx];
printf("%c",data_in);
rx_byte_cnt++;
rx_inx++;
bufptr += nbytes;
}
if(buffer[rx_inx-1]== 'O' && buffer[rx_inx]== 'K')
{
buffer[rx_inx+2]='\0';
printf("\n\n MODEM TEST SUCCESSFULL....\n");
break;
}
}
buffer[255]=0;
if(rx_byte_cnt==0)
{
printf("%s",buffer);
printf("\n\nMODEM TEST FAILED....\n");
}
printf("Number of bytes received is %d\n",rx_byte_cnt);
printf("Number of reads is %d\n",rx_inx);
printf("%s",buffer);
}
#endif
#ifdef LOOP_BACK
printf("STARTING UART 1 LOOP BACK TESTING.......\n\n");
usleep(200000);
for(i=0;i< strlen(tx_data);i++)
{
data_out=tx_data[i];
write(uart1_fd, &data_out, sizeof(data_out));
usleep(200000);
read(uart1_fd, &data_in, sizeof(data_in));
usleep(10000);
rx_buf[i]=data_in;
if(data_out!=data_in)
error_cnt++;
}
rx_buf[strlen(tx_data)+1]=0;
printf("%s",rx_buf);
if(error_cnt!=0)
printf("\nUART 1 LOOP BACK TEST FAILED....\n");
else
printf("\n\nUART 1 LOOP BACK TEST SUCCESS....\n");
#endif
tcsetattr(uart1_fd, TCSANOW, &old_options);
close(uart1_fd);
return 0;
}
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2010-08-11 18:19:25 Re: GPRS modem connection for BF537
Mike Frysinger (UNITED STATES)
Message: 92340
the #'s in the kconfig correspond to the raw number behind the GPO_PFx define. you can see the mapping in arch/blackfin/mach-bf537/include/mach/gpio.h.
however, unless your modem really needs ctsrts, it's probably best to ignore that step at first as misconfigured ctsrts can easily make connections hangs as you reported.
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2010-08-12 01:05:29 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92343
Looks like i need to follow up,the following logic in mapping the GPIO pins for UART1 CTS and RTS pins!!
PF0 ---> 0 --> GPI0_0
PF1 --->1--> GPI0_1
PF2 ---> 2--> GPI0_2
PF3 ---> 3--> GPI0_3
PF4 ---> 4--> GPI0_4
PF5 ---> 5--> GPI0_5
PF6 ---> 6--> GPI0_6
PF7 ---> 7--> GPI0_7
PF8 ---> 8--> GPI0_8
PF9 ---> 9--> GPI0_9
PF10 ---> 10--> GPI0_10
PF11 ---> 11--> GPI0_11
PF12 ---> 12--> GPI0_12
PF13 ---> 13--> GPI0_13
PF14 ---> 14--> GPI0_14
PF15 ---> 15--> GPI0_15
PG0 ---> 16--> GPI0_16
PG1 ---> 17--> GPI0_17
PG2 ---> 18--> GPI0_18
PG3 ---> 19--> GPI0_19
PG4 ---> 20--> GPI0_20
PG5 ---> 21--> GPI0_21
PG6 ---> 22--> GPI0_22
PG7-->23--> GPI0_23
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2010-08-12 01:23:21 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92346
Hehe, looks like there was delay in the post !!
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2010-08-13 00:52:41 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92392
Having some strange problem in the UART 1 communication in BF 537
I am not using the cts and rts pins.
These are the tests I have done
Test 1
I transmitted data from the BF537 board to the PC. I was able to see the data transmitted on the PC's minicom (configured for 9600-N-1 and no hardware and software flow control). I was able to send a file from PC's minicom application to the BF537 board and see the received data on the BF537's minicom.
Test 2
When modem is power reset, It does send some characters which i am able to see the minicom terminal of the PC.
But when i do the same test using the BF board, I dont receive anything
Test 3
Loopback of the UART 1 works fine
Test 4
communication with the modem from PC is pretty fine.
Can anybody give me a clue, why i am not able to have communication with the modem ?
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2010-08-18 05:52:30 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92549
Hurrrayyy !!
Problem solved !!
I had to make some small hardware changes in my uart driver board for things to work !!
Thanks a lot for all your support !
Thread can be closed !!!
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2010-08-18 06:06:09 Re: GPRS modem connection for BF537
Sonic Zhang (CHINA)
Message: 92550
Could you explain a bit on what is the problem?
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2010-08-26 06:34:13 Re: GPRS modem connection for BF537
Shyam sundar (INDIA)
Message: 92802
Sorry for the delayed posting
At the driver end at which the modem was connected,I shorted pins 4(DTR) and 7 (RTS) and made it high
I am using MAX 3232 IC.
I didnt use the cts and rts pins at the blackfin side