Analog input (ADC)

ocikgel

2011-05-03 23:56:48

hi , 


I have project  with mini6410 4.3"LCD 
{ 
  uname -a  =
  Linux FriendlyARM 2.6.28.6-FriendlyARM #4 Fri Sep 17 12:14:33 HKT 2010   
  armv6l unknown
}

{
 project is ecg program. 
 I designed interface with qt in c++ and my group friends made two sensors 
 that are 
 ecg (get heart pulse rate) and 
 temperature(get the body emperature).
 We connect these sensors on PIN27-PIN28(COM6--signal AIN1-AIN2)
                             (analog input)
}

After , I think firstly Analog Device Converter is invoked than 2
hexadecimal datas (that are generated by ADC ) are writing on registers.
Than , I must read these datas.


my /dev folder is = 
***************************************************************************
audio               s3c-pp              tty46
backlight           s3c-rotator         tty47
buttons             shm                 tty48
console             timer               tty49
controlC0           touchscreen         tty5
cpu_dma_latency     tty                 tty50
dsp                 tty0                tty51
fb0                 tty1                tty52
fb1                 tty10               tty53
fb2                 tty11               tty54
fb3                 tty12               tty55
full                tty13               tty56
i2c                 tty14               tty57
input               tty15               tty58
kmsg                tty16               tty59
leds                tty17               tty6
log                 tty18               tty60
loop                tty19               tty61
mem                 tty2                tty62
mixer               tty20               tty63
mtd0                tty21               tty7
mtd0ro              tty22               tty8
mtd1                tty23               tty9
mtd1ro              tty24               ttySAC0
mtd2                tty25               ttySAC1
mtd2ro              tty26               ttySAC2
mtdblock0           tty27               ttySAC3
mtdblock1           tty28               ubi_ctrl
mtdblock2           tty29               urandom
network_latency     tty3                usbdev1.1
network_throughput  tty30               usbdev1.1_ep00
null                tty31               usbdev1.1_ep81
pcmC0D0c            tty32               vcs
pcmC0D0p            tty33               vcs1
ppp                 tty34               vcs2
ptmx                tty35               vcs3
pts                 tty36               vcs4
pwm                 tty37               vcsa
random              tty38               vcsa1
root                tty39               vcsa2
rtc                 tty4                vcsa3
rtc0                tty40               vcsa4
s3c-cmm             tty41               video0
s3c-g2d             tty42               video1
s3c-g3d             tty43               video14
s3c-jpg             tty44               watchdog
s3c-mfc             tty45               zero
***************************************************************************

 However  :) I don't know how invoke ADC , how read these registers and 
 these register addresses :D 

 if you know solution , have source code in c/c++  , register addresses ,
 know how invoke adc in mini6410 with c/c++ , know reading registers or  
 have any suggestion  , 
 please help me in a short time :D 
 (I have a time problem because of deadline )
 
 :)

ps :  in my  /dev folder , I dont have adc. 
      I dont have mini6410_adc.c files  and drivers/char folder  in my 
      mini6410 . :/

ps 2 : I have to  use  analog input for sensors :)

do anybody know anything else about this topic ???????


best regards ,

davef

2011-05-04 02:39:27

Suggest you read the text after the subject line!

ocikgel

2011-05-04 02:53:55

My english is bad , so if  I said wrong things , I am sorry .

However , do you know any solution ?

davef

2011-05-04 04:08:23

I know how ADCs work on 8bit platforms.  I have not used the ADC on the
Samsung 32bit devices.

Using the ADC on the mini6410 should not be much (if any) different than
the mini2440.

Search <mini2440 adc> here and on Google.  There are many other sites that
have done ADC work on these devices.

Good luck!

_mx_

2011-05-04 07:01:45

Hello,

I have a similar problem. It may works if you generate the adc device node
by yourself. But I still don't know with which values this should work.

Can you post the output from "ls -lsa /dev" ??


Greets

ocikgel

2011-05-04 11:29:55

hi ,

 dear _mx_ ,  
 I dont know how I generate the adc device node :( 

 my  " ls -lsa /dev  "  is ;  
***************************************************************************
0 drwxr-xr-x    7 root     root            0 May  4 12:12 .
2 drwxr-xr-x    1 root     root         2048 Sep 15  2010 ..
0 crw-rw----    1 root     root      14,   4 May  4  2011 audio
0 crw-rw----    1 root     root      10,  63 May  4  2011 backlight
0 crw-rw----    1 root     root      10,  61 May  4  2011 buttons
0 crw-rw----    1 root     root       5,   1 May  4 12:12 console
0 crw-rw----    1 root     root     116,   0 May  4  2011 controlC0
0 crw-rw----    1 root     root      10,  58 May  4  2011 cpu_dma_latency
0 crw-rw----    1 root     root      14,   3 May  4  2011 dsp
0 crw-rw-rw-    1 root     root      29,   0 May  4  2011 fb0
0 crw-rw-rw-    1 root     root      29,   1 May  4  2011 fb1
0 crw-rw-rw-    1 root     root      29,   2 May  4  2011 fb2
0 crw-rw-rw-    1 root     root      29,   3 May  4  2011 fb3
0 crw-rw-rw-    1 root     root       1,   7 May  4  2011 full
0 drwxr-xr-x    2 root     root            0 May  4  2011 i2c
0 drwxr-xr-x    2 root     root            0 May  4  2011 input
0 crw-rw----    1 root     root       1,  11 May  4  2011 kmsg
0 crw-rw----    1 root     root      10,  62 May  4  2011 leds
0 srw-rw-rw-    1 root     root            0 May  4 12:12 log
0 drwxr-xr-x    2 root     root            0 May  4  2011 loop
0 crw-rw----    1 root     root       1,   1 May  4  2011 mem
0 crw-rw----    1 root     root      14,   0 May  4  2011 mixer
0 crw-rw----    1 root     root      90,   0 May  4  2011 mtd0
0 crw-rw----    1 root     root      90,   1 May  4  2011 mtd0ro
0 crw-rw----    1 root     root      90,   2 May  4  2011 mtd1
0 crw-rw----    1 root     root      90,   3 May  4  2011 mtd1ro
0 crw-rw----    1 root     root      90,   4 May  4  2011 mtd2
0 crw-rw----    1 root     root      90,   5 May  4  2011 mtd2ro
0 brw-rw----    1 root     root      31,   0 May  4  2011 mtdblock0
0 brw-rw----    1 root     root      31,   1 May  4  2011 mtdblock1
0 brw-rw----    1 root     root      31,   2 May  4  2011 mtdblock2
0 crw-rw----    1 root     root      10,  57 May  4  2011 network_latency
0 crw-rw----    1 root     root      10,  56 May  4  2011  
                                                         network_throughput
0 crw-rw-rw-    1 root     root       1,   3 May  4  2011 null
0 crw-rw----    1 root     root     116,  24 May  4  2011 pcmC0D0c
0 crw-rw----    1 root     root     116,  16 May  4  2011 pcmC0D0p
0 crw-rw----    1 root     root     108,   0 May  4  2011 ppp
0 crw-rw-rw-    1 root     root       5,   2 May  4 12:15 ptmx
0 drwxr-xr-x    2 root     root            0 Jan  1  1970 pts
0 crw-rw----    1 root     root      10,  60 May  4  2011 pwm
0 crw-rw-rw-    1 root     root       1,   8 May  4  2011 random
0 lrwxrwxrwx    1 root     root            9 May  4  2011 root -> mtdblock2
0 crw-r--r--    1 root     root     254,   0 May  4  2011 rtc
0 lrwxrwxrwx    1 root     root            3 May  4  2011 rtc0 -> rtc
0 crw-rw----    1 root     root      10, 250 May  4  2011 s3c-cmm
0 crw-rw----    1 root     root      10, 220 May  4  2011 s3c-g2d
0 crw-rw----    1 root     root      10, 249 May  4  2011 s3c-g3d
0 crw-rw----    1 root     root      10, 254 May  4  2011 s3c-jpg
0 crw-rw----    1 root     root      10, 252 May  4  2011 s3c-mfc
0 crw-rw----    1 root     root      10, 253 May  4  2011 s3c-pp
0 crw-rw----    1 root     root      10, 230 May  4  2011 s3c-rotator
0 brw-rw----    1 root     root       8,   0 May  4 12:12 sda
0 crw-rw----    1 root     root      21,   0 May  4 12:12 sg0
0 drwxrwxrwt    2 root     root           40 May  4  2011 shm
0 crw-rw----    1 root     root     116,  33 May  4  2011 timer
0 crw-rw----    1 root     root      10, 180 May  4  2011 touchscreen
0 crw-rw-rw-    1 root     root       5,   0 May  4  2011 tty
0 crw-rw----    1 root     tty        4,   0 May  4 12:12 tty0
0 crw-rw----    1 root     tty        4,   1 May  4 12:12 tty1
0 crw-rw----    1 root     tty        4,  10 May  4  2011 tty10
0 crw-rw----    1 root     tty        4,  11 May  4  2011 tty11
0 crw-rw----    1 root     tty        4,  12 May  4  2011 tty12
0 crw-rw----    1 root     tty        4,  13 May  4  2011 tty13
0 crw-rw----    1 root     tty        4,  14 May  4  2011 tty14
0 crw-rw----    1 root     tty        4,  15 May  4  2011 tty15
0 crw-rw----    1 root     tty        4,  16 May  4  2011 tty16
0 crw-rw----    1 root     tty        4,  17 May  4  2011 tty17
0 crw-rw----    1 root     tty        4,  18 May  4  2011 tty18
0 crw-rw----    1 root     tty        4,  19 May  4  2011 tty19
0 crw-rw----    1 root     tty        4,   2 May  4 12:12 tty2
0 crw-rw----    1 root     tty        4,  20 May  4  2011 tty20
0 crw-rw----    1 root     tty        4,  21 May  4  2011 tty21
0 crw-rw----    1 root     tty        4,  22 May  4  2011 tty22
0 crw-rw----    1 root     tty        4,  23 May  4  2011 tty23
0 crw-rw----    1 root     tty        4,  24 May  4  2011 tty24
0 crw-rw----    1 root     tty        4,  25 May  4  2011 tty25
0 crw-rw----    1 root     tty        4,  26 May  4  2011 tty26
0 crw-rw----    1 root     tty        4,  27 May  4  2011 tty27
0 crw-rw----    1 root     tty        4,  28 May  4  2011 tty28
0 crw-rw----    1 root     tty        4,  29 May  4  2011 tty29
0 crw-rw----    1 root     tty        4,   3 May  4 12:12 tty3
0 crw-rw----    1 root     tty        4,  30 May  4  2011 tty30
0 crw-rw----    1 root     tty        4,  31 May  4  2011 tty31
0 crw-rw----    1 root     tty        4,  32 May  4  2011 tty32
0 crw-rw----    1 root     tty        4,  33 May  4  2011 tty33
0 crw-rw----    1 root     tty        4,  34 May  4  2011 tty34
0 crw-rw----    1 root     tty        4,  35 May  4  2011 tty35
0 crw-rw----    1 root     tty        4,  36 May  4  2011 tty36
0 crw-rw----    1 root     tty        4,  37 May  4  2011 tty37
0 crw-rw----    1 root     tty        4,  38 May  4  2011 tty38
0 crw-rw----    1 root     tty        4,  39 May  4  2011 tty39
0 crw-rw----    1 root     tty        4,   4 May  4 12:12 tty4
0 crw-rw----    1 root     tty        4,  40 May  4  2011 tty40
0 crw-rw----    1 root     tty        4,  41 May  4  2011 tty41
0 crw-rw----    1 root     tty        4,  42 May  4  2011 tty42
0 crw-rw----    1 root     tty        4,  43 May  4  2011 tty43
0 crw-rw----    1 root     tty        4,  44 May  4  2011 tty44
0 crw-rw----    1 root     tty        4,  45 May  4  2011 tty45
0 crw-rw----    1 root     tty        4,  46 May  4  2011 tty46
0 crw-rw----    1 root     tty        4,  47 May  4  2011 tty47
0 crw-rw----    1 root     tty        4,  48 May  4  2011 tty48
0 crw-rw----    1 root     tty        4,  49 May  4  2011 tty49
0 crw-rw----    1 root     tty        4,   5 May  4  2011 tty5
0 crw-rw----    1 root     tty        4,  50 May  4  2011 tty50
0 crw-rw----    1 root     tty        4,  51 May  4  2011 tty51
0 crw-rw----    1 root     tty        4,  52 May  4  2011 tty52
0 crw-rw----    1 root     tty        4,  53 May  4  2011 tty53
0 crw-rw----    1 root     tty        4,  54 May  4  2011 tty54
0 crw-rw----    1 root     tty        4,  55 May  4  2011 tty55
0 crw-rw----    1 root     tty        4,  56 May  4  2011 tty56
0 crw-rw----    1 root     tty        4,  57 May  4  2011 tty57
0 crw-rw----    1 root     tty        4,  58 May  4  2011 tty58
0 crw-rw----    1 root     tty        4,  59 May  4  2011 tty59
0 crw-rw----    1 root     tty        4,   6 May  4  2011 tty6
0 crw-rw----    1 root     tty        4,  60 May  4  2011 tty60
0 crw-rw----    1 root     tty        4,  61 May  4  2011 tty61
0 crw-rw----    1 root     tty        4,  62 May  4  2011 tty62
0 crw-rw----    1 root     tty        4,  63 May  4  2011 tty63
0 crw-rw----    1 root     tty        4,   7 May  4  2011 tty7
0 crw-rw----    1 root     tty        4,   8 May  4  2011 tty8
0 crw-rw----    1 root     tty        4,   9 May  4  2011 tty9
0 crw-rw-rw-    1 root     tty      204,  64 May  4 12:12 ttySAC0
0 crw-rw-rw-    1 root     tty      204,  65 May  4  2011 ttySAC1
0 crw-rw-rw-    1 root     tty      204,  66 May  4  2011 ttySAC2
0 crw-rw-rw-    1 root     tty      204,  67 May  4  2011 ttySAC3
0 crw-rw----    1 root     root      10,  59 May  4  2011 ubi_ctrl
0 brw-------    1 root     root       8,   1 May  4 12:12 udisk
0 crw-rw----    1 root     root       1,   9 May  4  2011 urandom
0 crw-rw----    1 root     root     189,   0 May  4  2011 usbdev1.1
0 crw-rw----    1 root     root     253,   1 May  4  2011 usbdev1.1_ep00
0 crw-rw----    1 root     root     253,   0 May  4  2011 usbdev1.1_ep81
0 crw-rw----    1 root     root     189,   1 May  4  2011 usbdev1.2
0 crw-rw----    1 root     root     253,   4 May  4  2011 usbdev1.2_ep00
0 crw-rw----    1 root     root     253,   3 May  4  2011 usbdev1.2_ep02
0 crw-rw----    1 root     root     253,   2 May  4  2011 usbdev1.2_ep81
0 crw-rw----    1 root     root       7,   0 May  4  2011 vcs
0 crw-rw----    1 root     root       7,   1 May  4 12:12 vcs1
0 crw-rw----    1 root     root       7,   2 May  4 12:12 vcs2
0 crw-rw----    1 root     root       7,   3 May  4 12:12 vcs3
0 crw-rw----    1 root     root       7,   4 May  4 12:12 vcs4
0 crw-rw----    1 root     root       7, 128 May  4  2011 vcsa
0 crw-rw----    1 root     root       7, 129 May  4 12:12 vcsa1
0 crw-rw----    1 root     root       7, 130 May  4 12:12 vcsa2
0 crw-rw----    1 root     root       7, 131 May  4 12:12 vcsa3
0 crw-rw----    1 root     root       7, 132 May  4 12:12 vcsa4
0 crw-rw----    1 root     root      81,   0 May  4  2011 video0
0 crw-rw----    1 root     root      81,   1 May  4  2011 video1
0 crw-rw----    1 root     root      81,  14 May  4  2011 video14
0 c...stripped-down

ocikgel

2011-05-04 11:31:27

... continued =

0 crw-rw----    1 root     root      10, 130 May  4  2011 watchdog
0 crw-rw-rw-    1 root     root       1,   5 May  4  2011 zero

***************************************************************************

_mx_

2011-05-04 13:21:44

Hello,

to generate the led device node it works with this:

mknod -m 0660 /dev/leds c 10 62

But I don't know the values for the adc. I have the same problem :(

Greets

_mx_

2011-05-04 17:26:24

Hello,

try this:

mknod -m 0669 /dev/adc c 10 59

with my Mini2440 this works!

Wish you luck!

_mx_

Juergen Beisert

2011-05-04 22:33:54

You need to activate the s3c-hwmon driver. But this needs some patches in
your kernel. After that you can read all the channels in:

root@mini2440:/sys/devices/platform/s3c24xx-adc/s3c-hwmon ls
driver     in1_input  in3_input  in5_input  in7_input  subsystem
hwmon      in1_label  in3_label  in5_label  in7_label  uevent
in0_input  in2_input  in4_input  in6_input  modalias
in0_label  in2_label  in4_label  in6_label  power

Sorry, no simple solution.

Nambi

2011-05-05 01:08:59

Hi Juergen,

Can you please tell me where we can get the patches for the Kernel, if it
is already available.

Thank you,

Nambi

ocikgel

2011-05-05 03:42:35

hi ,

dear _mx_ , firstly thanks for your interest :)

I tried 
         mknod -m 0669 /dev/adc c 10 59

and /dev/adc is appeared :)

, but when I run this test code = 
************************************
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <linux/fs.h>
#include <errno.h>
#include <string.h>

int main(void)
{
  fprintf(stderr, "press Ctrl-C to stop\n");
  int fd = open("/dev/adc", 0);
  if (fd < 0) {
    perror("open ADC device:");
    return 1;
  }
  for(;;) {
    char buffer[30];
    int len = read(fd, buffer, sizeof buffer -1);
    if (len > 0) {
      buffer[len] = '\0';
      int value = -1;
      sscanf(buffer, "%d", &value);
      printf("ADC Value: %d\n", value);
    } else {
      perror("read ADC device:");
      return 1;
    }
    system("sleep 0.2");
  }
  
  close(fd);
}
*******************************************

I have this output = 

 press Ctrl-C to stop
 read ADC device:: Invalid argument

:( 

in that time I did not connect any sensors , so I hope I get this output
"ADC Value : -1" , but I  had  this output : "read ADC device:: Invalid
argument"


what is the problem ? 
what do you suggest me ?  :/

linux_support

2011-05-05 06:51:32

Hi ocikgel
I have replied to one of your previous post that if the respective driver
of the ADC is not compiled with the kernel then you will not be able to use
the ADC devices. Even if you make the nodes manually, the drivers has to be
there. 
The file i mentioned mini6410_adc.c is in the kernel source code and this
file is the driver of the ADC. I am again repeating , you will not find
this file in your mini6410 kit, this file is the kernel source code.

Regards
Vector Institute
linuxsupport@vectorindia.org
http://www.vectorindia.org

_mx_

2011-05-05 07:25:36

sorry, my mistake

try this:

mknod -m 0660 /dev/adc c 10 59

may you have to remove your current /dev/adc first

After that you can try 

cat /dev/adc

then you should see the adc values of the on board poti (at least on the
mini2440, i don't know much about the mini6410)

good luck!

Juergen Beisert

2011-05-05 10:14:52

Nambi:

---
 arch/arm/mach-s3c2440/Kconfig         |    1 
 arch/arm/mach-s3c2440/mach-mini2440.c |   50
++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

Index: linux-2.6.38/arch/arm/mach-s3c2440/mach-mini2440.c
===================================================================
--- linux-2.6.38.orig/arch/arm/mach-s3c2440/mach-mini2440.c
+++ linux-2.6.38/arch/arm/mach-s3c2440/mach-mini2440.c
@@ -57,6 +57,7 @@
 #include <plat/clock.h>
 #include <plat/devs.h>
 #include <plat/cpu.h>
+#include <plat/hwmon.h>
 
 #include <sound/s3c24xx_uda134x.h>
 
@@ -544,6 +545,53 @@ static struct s3c2410_ts_mach_info mini2
   .oversampling_shift = 0,
 };
 
+static struct s3c_hwmon_chcfg mini2440_adc_chcfg[8] = {
+  {
+    .name = "AIN0",  /* connected to CON4/5 and W1 */
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "AIN1",  /* connected to CON4/6 */
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "AIN2",  /* connected to CON4/7 */
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "AIN3",  /* connected to CON4/8 */
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "TSYM",
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "TSYP",
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "TSXM",
+    .mult = 3300,
+    .div = 1023,
+  }, {
+    .name = "TSXP",
+    .mult = 3300,
+    .div = 1023,
+  },
+};
+
+static struct s3c_hwmon_pdata mini2440_adc __initdata = {
+  .in[0] = &mini2440_adc_chcfg[0],
+  .in[1] = &mini2440_adc_chcfg[1],
+  .in[2] = &mini2440_adc_chcfg[2],
+  .in[3] = &mini2440_adc_chcfg[3],
+  .in[4] = &mini2440_adc_chcfg[4],
+  .in[5] = &mini2440_adc_chcfg[5],
+  .in[6] = &mini2440_adc_chcfg[6],
+  .in[7] = &mini2440_adc_chcfg[6],
+};
+
 static struct platform_device *mini2440_devices[] __initdata = {
   &s3c_device_ohci,
   &s3c_device_wdt,
@@ -560,6 +608,7 @@ static struct platform_device *mini2440_
   &mini2440_audio,
   &samsung_asoc_dma,
   &s3c_device_adc,
+  &s3c_device_hwmon,
 };
 
 static void __init mini2440_map_io(void)
@@ -721,6 +770,7 @@ static void __init mini2440_init(void)
   s3c_nand_set_platdata(&mini2440_nand_info);
   s3c_i2c0_set_platdata(NULL);
   s3c24xx_ts_set_platdata(&mini2440_ts_cfg);
+  s3c_hwmon_set_platdata(&mini2440_adc);
 
   i2c_register_board_info(0, mini2440_i2c_devs,
         ARRAY_SIZE(mini2440_i2c_devs));
Index: linux-2.6.38/arch/arm/mach-s3c2440/Kconfig
===================================================================
--- linux-2.6.38.orig/arch/arm/mach-s3c2440/Kconfig
+++ linux-2.6.38/arch/arm/mach-s3c2440/Kconfig
@@ -187,6 +187,7 @@ config MACH_MINI2440
   select S3C_DEV_NAND
   select S3C_DEV_USB_HOST
   select TOUCHSCREEN_S3C2410
+  select S3C_DEV_HWMON
   help
     Say Y here to select support for the MINI2440. Is a 10cm x 10cm board
     available via various sources. It can come with a 3.5" or 7" touch
LCD.

ocikgel

2011-05-06 16:13:38

hi, 

@ _mx_

I tried this command
mknod -m 0660 /dev/adc c 10 59

and /dev/adc is appeared but I tried to open and use I got segmentation
fault :d

now , I found new way to achieve the register values , but  I must know 
AIN1-AIN2  physical addresses where are stored  what are the adresses ? 

(like 0x7E00B000) ???

Juergen Beisert

2011-05-08 13:19:54

Nambi,

you could try my board support package for the mini2440. It contains the
required patch to make the ADCs available from userland. You can find it
here: http://www.oselas.org/oselas/bsp/pengutronix/index_en.html

Peter

2012-02-24 10:57:44

@Juergen,

I am using Linux 3.1 from the same BSP, kernel compile and installed well,
but I am unable to locate in0_input. 

ls /sys/devices/platform/s3c24xx-adc/s3c-hwmon
modalias   power      subsystem  uevent

there is no in0_input.

Please let me know how can I use all AIN pin?

Thanks & Regards,
Peter.

sunny leon

2014-10-31 08:04:35

Hello,

How to write a ADC user level read code in C++

Ajit

2016-06-19 07:40:58

@Juergen

How to apply those patches to kernel linux-2.6.32.2??