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Interfacing

CAN controller

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hjoe  

Nov 20, 2014 14:23

FPeter replied at Mon Nov 17, 2014 12:08
Here is my solution for CAN transceiver: MCP2551 with voltage divider

This small module can be fitt ...

Hello FPeter

how many of the Bpi-CAN_3 do you have? Do you sell?

Heinz
FPeter  

Nov 21, 2014 00:54

hjoe replied at Thu Nov 20, 2014 14:23
Hello FPeter

how many of the Bpi-CAN_3 do you have? Do you sell?

hello hjoe!

it's a homemade version, so i made only one but i can share its eagle project files

but since i realized that there is an internal pullup to 5V on it's TXD pin, it's not a perfect solution despite of the voltage divider on RXD pin...



so i think i will change it to a real 3.3V transciever like MAX3051 or SN65HVD23x family...
hjoe  

Nov 21, 2014 06:07

If you have the choice, take Texas Instruments.
TI is active in the standardization, as far as I know TI was the first one offering 3.3V transceivers and TI is now working on CAN FD transceivers.
hjoe  

Nov 21, 2014 12:25

Can someone of the can4linux users please check if my calculation of the bit timing register is correct. Especially the value for  1 Mbit/s.
In the mean time, I will add the controller to http://www.bittiming.can-wiki.info
flaviobrums  

Nov 21, 2014 13:07

hjoe replied at Thu Nov 20, 2014 14:17
you don't need any special tools to set the bitrate for can4linux devices.
Before opening any /dev ...

Hi,

the receive tool is enough for me, and I use it to set the bus speed also.

Even if I try to redirect the output to a file the result is the same.

But my main problem is the board hangs up when many frames are received.
flaviobrums  

Nov 21, 2014 13:32

I tested it with these settings:

AccCode          :-1
AccMask          :-1
ArbitrationLost  :0
Base             :29539328
Baud             :1000
CAN clock        :24000000
Chipset          :
dbgMask          :0
framelength      :8
IOModel          :m
IRQ              :58
OpenCount        :      0(4)
Outc             :0
Overrun          :0
RxErr            :0
RxErrCounter     :0
Timeout          :100
TxErr            :0
TxErrCounter     :0
version          :4.3_BANANAPI SVN version 433



using ./receive -n -s 100 -l

Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=12:   1416597819.726499 id=264/0x00000108
        len=8 flags=0x80 : bD  ( 8): 55 aa 55 aa 07 10 00 00
Received with ret=12:            0.000264 id=0/0x00000000
        len=-28357 flags=0x1007aa55 : eRF (-28357):
Received with ret=12:            0.000000 id=270600192/0x10210800
        len=0 flags=0xb23e9 : BRF [ 0]:
Received with ret=12:   2857697280.268937813 id=730461/0x000b255d
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:   1416597819.730857 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=12:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=2:   1416597819.765786 id=264/0x00000108
        len=8 flags=0x00 : bD  ( 8): 55 aa 55 aa 07 10 00 00
Received with ret=2:            0.000264 id=0/0x00000000
        len=-28357 flags=0x1007aa55 : eRF (-28357):
Received with ret=0



while syslog prints out

Nov 21 19:23:39 lemaker kernel: [  662.347950] can4linux: CAN[0][0] RX: FIFO overrun
Nov 21 19:23:39 lemaker kernel: [  662.351530] can4linux: CAN[0] Rx: Overrun Status
Nov 21 19:23:39 lemaker kernel: [  662.355106] can4linux: CAN[0] Rx: Overrun Status
Nov 21 19:23:39 lemaker kernel: [  662.394403] can4linux: CAN[0] Rx: Overrun Status
Nov 21 19:23:41 lemaker kernel: [  664.314068] can4linux: CAN[0] Rx: Overrun Status

than the board hangs


using ./receive -l -d -t 4 -n -B 2000 -s 1000
./receive  V SVN $Revision: 433 $, Nov 16 2014
(c) 2012-2014 H.J. Oertel
using canmsg_t with 88 bytes
  CAN FD data structure used
  open CAN device "/dev/can0" in non-blocking mode
Change to Listen Only Mode
Change to Time Stamp Mode 4
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=0
Received with ret=14:   1416598397.389327 id=264/0x00000108
        len=8 flags=0x80 : bD  ( 8): 55 aa 55 aa 07 10 00 00
Received with ret=14:            0.000264 id=0/0x00000000
        len=-27779 flags=0x1007aa55 : eRF (-27779):
Received with ret=14:            0.000000 id=270600192/0x10210800
        len=0 flags=0x5fed5 : eRF ( 0):
Received with ret=14:   2857697280.268937813 id=393292/0x0006004c
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:   1416598397.393683 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x1007aa55 : eRF ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=7:   1416598398.578522 id=264/0x00000108
        len=8 flags=0x00 : bD  ( 8): 55 aa 55 aa 07 10 00 00
Received with ret=7:            0.000264 id=0/0x00000000
        len=-27778 flags=0x1007aa55 : eRF (-27778):
Received with ret=7:        61512.000000 id=1030997/0x000fbb55
        len=0 flags=0x4c0a : BD  ( 0):
Received with ret=7:   2857697280.268937813 id=393292/0x0006004c
        len=0 flags=0x00 : bD  ( 0):
Received with ret=7:   1416598397.393683 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):
Received with ret=7:            0.000000 id=0/0x00000000
        len=0 flags=0x1007aa55 : eRF ( 0):
Received with ret=7:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):

while syslog prints out

Nov 21 19:33:17 lemaker kernel: [  200.740885] can4linux: CAN[0][0] RX: FIFO overrun
Nov 21 19:33:17 lemaker kernel: [  200.744466] can4linux: CAN[0] Rx: Overrun Status
Nov 21 19:33:17 lemaker kernel: [  200.748042] can4linux: CAN[0] Rx: Overrun Status

than the board hangs again

if I simply use ./receive the tool prints frames at fast speed but the board hang up as before
hjoe  

Nov 21, 2014 14:12

Flavio,
if you specify -n, that means non blocking, together with -s 100
receive looks every 100ms if there are messages and reads these messages. But 100ms are a long time.

according to your log:
Received with ret=14:            0.000000 id=0/0x00000000
        len=0 flags=0x00 : bD  ( 0):

someone is sending CAN frames with ID=0 and zero data bytes. With 1 Mbit/s such a Fame is about 60 µs long and with a high bus load you will receive many frames in 100 ms. I always use blocking and something like
$ receive -t3 -H

-t3 displays the time between consecutive frames. And -H looks (for me) much nicer.
hjoe  

Nov 21, 2014 14:43

I have some problems at the moment with 1 Mbit/s. Thats why I asked to verify the bi timing register value.
But I did test with 500Kbit/s. I send frames with a desktop PC
can_send -t11  -s0 -T 1024  -b 500
this will send 1024 frames as fast as possible
The Banana receives it
receive -H -b 500 > log

After the transmitter has finished I stop the receiver. I do
wc -l log
1024
and see, that exactly as much as sent receive have received, 1024 frames
Looking at the log file log:
  1416602290.130315         0/0x00000000 : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.130568         1/0x00000001 : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.130816         2/0x00000002 : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.131059         3/0x00000003 : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.131308         4/0x00000004 : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.131554         5/0x00000005 : bD ( 8): 55 02 03 04 05 06 07 aa
.........
1416602290.378913      1018/0x000003fa : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.379169      1019/0x000003fb : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.379427      1020/0x000003fc : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.379683      1021/0x000003fd : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.379943      1022/0x000003fe : bD ( 8): 55 02 03 04 05 06 07 aa
  1416602290.380201      1023/0x000003ff : bD ( 8): 55 02 03 04 05 06 07 aa

it took
1416602290.380201-1416602290.130315 = .249886
250 ms for transmitting  1024 frames with 8 byte each.

.249886/1024 = .000244
each 244µs a frame was received, That's really nearly 100% bus load at 500 Kbit/s.
No Frame lost.

I hope to get the basic test done with 1 Mbit/s today or tomorrow.
Heinz
hjoe  

Nov 21, 2014 16:11

I have changed the bit timing values for 1 Mbit/s to 0x00090001, sample point at  83.3 %. Now it works for me. I don't know how I cam to the previous value. Please check use these values. I have checked it in into svn at SourceForge.
flaviobrums  

Nov 22, 2014 04:23

Hi,

using 436 revision and ./receive -t3 -H

Correct frame id are:
0x00000090
0x00000108
0x000007f8
all others are read errors

  2.            0.009697       144/0x00000090 : bD  ( 6): 02 00 00 00 1d 5e
  3.            0.000004       144/0x00000090 : bD  ( 4): 66 cc 66 cc
  4.            0.000006       144/0x00000090 : bD  ( 8): 55 aa 55 aa 02 10 78 00
  5.            0.000004       144/0x00000090 : bD  ( 8): 00 00 00 00 00 00 00 00
  6.            0.000004       144/0x00000090 : bD  ( 8): 00 00 00 00 00 00 00 00
  7.            0.000004       128/0x00000080 : bD  ( 1): 00
  8.            0.000001       144/0x00000090 : bD  ( 8): e8 ff ff ff 08 12 00 55
  9.            0.008682       144/0x00000090 : bD  ( 4): 66 cc 66 cc
  10.            0.000003       144/0x00000090 : bD  ( 8): 55 aa 55 aa 01 10 0e 00
  11.            0.000006       144/0x00000090 : bD  ( 8): f2 ff ff ff 05 00 00 00
  12.            0.000004       144/0x00000090 : bD  ( 6): 05 00 00 00 40 5e
  13.            0.000003       144/0x00000090 : bD  ( 4): 66 cc 66 cc
  14.            0.000003       144/0x00000090 : bD  ( 6): 02 00 00 00 41 5e
  15.            0.008927       144/0x00000090 : bD  ( 8): d3 0d d0 bb 83 b5 ed 3e
  16.            0.000004       144/0x00000090 : bD  ( 8): c8 2c ec bb 80 2b a6 3b
  17.            0.000004       144/0x00000090 : bD  ( 8): 00 22 a8 b9 00 00 00 00
  18.            0.000004       144/0x00000090 : bD  ( 8): 00 00 00 00 a7 52 ad bb
  19.            0.000004       144/0x00000090 : bD  ( 6): f7 ff ff ff 62 5e
  20.            0.000001       144/0x00000090 : bD  ( 8): 55 aa 55 aa 01 10 0e 00
  21.            0.000001       144/0x00000090 : bD  ( 8): 55 aa 55 aa 02 10 78 00
  22.            0.008429       264/0x00000108 : bD  ( 8): 00 00 00 00 20 fc 00 00
  23.            0.007239       264/0x00000108 : bD  ( 8): 48 00 00 00 00 00 00 00
  24.            0.000018       280/0x00000118 : bD  ( 4): 66 cc 66 cc
  25.            0.000003       144/0x00000090 : bD  ( 8): 55 aa 55 aa 01 10 0e 00
  26.            0.000004       144/0x00000090 : bD  ( 8): 15 00 00 00 f2 ff ff ff
  27.            0.000004       144/0x00000090 : bD  ( 8): 00 00 30 00 00 00 eb 65
  28.            0.000004       144/0x00000090 : bD  ( 8): fe ff ff ff dd ff ff ff
  29.            0.000000         0/0x00000000 : bD  ( 0):
  30.            0.000000         2/0x00000002 : bD  ( 1): 00
  31.            0.000001         0/0x00000000 : bD  ( 0):
  32.            0.000000        64/0x00000040 : bD  ( 0):
  33.            0.000000       685/0x000002ad : bD  ( 0):
  34.            0.000000      1360/0x00000550 : bR  ( 5):
  35.            0.000000       112/0x00000070 : bD  ( 0):
  36.            0.000003       144/0x00000090 : bD  ( 8): f9 ff ff ff f7 ff ff ff
  37.            0.007239       144/0x00000090 : bD  ( 6): ed ff ff ff 8c 5e
  38.            0.000003       144/0x00000090 : bD  ( 4): 66 cc 66 cc
  39.            0.000001       264/0x00000108 : bD  ( 8): 55 aa 55 aa 09 10 b8 00
  40.            0.006552       264/0x00000108 : bD  ( 8): 44 4a 49 01 18 42 18 42
  41.            0.000003       264/0x00000108 : bD  ( 8): 18 42 18 42 00 00 00 00
  42.            0.000001      2040/0x000007f8 : bD  ( 1): 04
  43.            0.000001      2040/0x000007f8 : bD  ( 4): 66 cc 66 cc
  44.            0.000003       144/0x00000090 : bD  ( 8): 55 aa 55 aa 01 10 0e 00
  45.            0.005151       144/0x00000090 : bD  ( 6): 05 00 00 00 94 5e
  46.            0.000003       144/0x00000090 : bD  ( 4): 66 cc 66 cc
  47.            0.000013       133/0x00000085 : bD  ( 9): 00 08 21 00 44 4a 49 01
  48.            0.000001       144/0x00000090 : bD  ( 6): 01 00 00 00 98 5e
  49.            0.000001       144/0x00000090 : bD  ( 4): 66 cc 66 cc
  50.            0.000001       144/0x00000090 : bD  ( 2): 66 cc
  51.            0.000001       264/0x00000108 : bD  ( 8): 00 00 00 00 00 00 00 00
  52.            0.005131       144/0x00000090 : bD  ( 2): 66 cc
  53.            0.000001       144/0x00000090 : bD  ( 6): 05 00 00 00 94 5e
  54.            0.006876       144/0x00000090 : bD  ( 4): 12 00 7b 8c
  55.            0.000001 279899612/0x10aeeddc : eR  (15):
  56.            0.000000        64/0x00000040 : bD  (14): 00 60 f8 1b bd 60 7f 2d
  57.            0.005280        48/0x00000030 : bD  (12): 00 fc ff ff ff 9e 5e 02
  58.            0.000001         3/0x00000003 : bD  ( 2): cc 08
  59.            0.000001         2/0x00000002 : bD  ( 1): aa
  60.            0.003739      1360/0x00000550 : bR  ( 5):
Copy the Code
Than the board hangs again

The distance from the board and the device is less than 30cm
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