CAN2Ethernet

If you are searching for a cheap, fast and reliable CAN interface with Ethernet connection consider using CAN-CAN Interface
or the Banana Pi with integrated CAN-Controller

CAN + Raspberry Pi

Please have a look at Raspberry Forum

Summary

Efforts connecting a MCP2515 CAN controller to Raspberry Pi. Please note: This is not ment to be a description for Linux beginners.
The combination of RPi and MCP2515 isn't perfect - you need some time to get a reliable setup working.

Wiring

P1-01 3V3    -> MCP2515 VCC
P1-02 5V     -> MCP2551 VCC
P1-06 GND    -> MCP25xx GND
P1-19 GPIO10 -> MOSI
P1-21 GPIO9  -> MISO
P1-22 GPIO25 -> MCP2515 INT
P1-23 GPIO11 -> SCK
P1-24 GPIO8  -> CS0

Rasperry Pi GPIOs use 3V3 as the MCP2515 does. The tranceiver uses 5V - the R1/R2 combination is a voltage divider.

Improved Design

I've seen commercial products based on the schematic above. Strange, because these days you should use a MCP2562 instead of the (not recommend for new designs) MCP2551. The MCP2562 can operate with two supply voltages (e.g. 3V3 IO / 5V CANBUS) which avoids the two resistors R1/R2 and is more reliable. Here the new design:

If you want to try this design: +-10 PCBs from Dirtypcbs.com

CAN test

Make sure that you have all necessary modules installed #

spi-bcm2708
can
can-dev
can-raw
mcp251x

# Maerklin Gleisbox (60112 and 60113) uses 250000
# loopback mode for testing
ip link set can0 up type can bitrate 125000 loopback on

root@raspberrypi ~ # dmesg
[  394.151290] bcm2708_spi bcm2708_spi.0: SPI Controller at 0x20204000 (irq 80)
[  465.325599] can: controller area network core (rev 20090105 abi 8)
[  465.325968] NET: Registered protocol family 29
[  523.007604] CAN device driver interface
[  560.310129] can: raw protocol (rev 20090105)
[  565.070666] can: broadcast manager protocol (rev 20090105 t)
[  593.259813] mcp251x spi0.0: CANSTAT 0x80 CANCTRL 0x07
[  593.266881] mcp251x spi0.0: probed
[  638.710821] mcp251x spi0.0: CNF: 0x03 0xb5 0x01

# on second terminal
root@raspberrypi ~ # candump any,0:0,#FFFFFFFF
  can0  123  [4] DE AD BE EF
  can0  123  [4] DE AD BE EF
  can0  123  [4] DE AD BE EF
  can0  123  [4] DE AD BE EF

root@raspberrypi ~ # cansend can0 123#deadbeef
root@raspberrypi ~ # cansend can0 123#deadbeef

root@raspberrypi ~ # ip -s -d link show can0
3: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT qlen 10
    link/can 
    can <LOOPBACK> state ERROR-ACTIVE restart-ms 0 
    bitrate 125000 sample-point 0.875 
    tq 500 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1
    mcp251x: tseg1 3..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
    clock 8000000
    re-started bus-errors arbit-lost error-warn error-pass bus-off
    0          0          0          0          0          0         
    RX: bytes  packets  errors  dropped overrun mcast   
    8          2        0       0       0       0      
    TX: bytes  packets  errors  dropped carrier collsns 
    8          2        0       0       0       0      

root@raspberrypi ~# cat /proc/interrupts
           CPU0       
  3:     192391   ARMCTRL  BCM2708 Timer Tick
 52:          2   ARMCTRL  BCM2708 GPIO catchall handler
 65:          2   ARMCTRL  ARM Mailbox IRQ
 66:          1   ARMCTRL  VCHIQ doorbell
 75:   14889016   ARMCTRL  dwc_otg, dwc_otg_hcd:usb1
 77:      11994   ARMCTRL  bcm2708_sdhci (dma)
 80:         58   ARMCTRL  bcm2708_spi.0
 83:         22   ARMCTRL  uart-pl011
 84:      21565   ARMCTRL  mmc0
110:          2      GPIO  mcp251x
Err:          0

Misc

Alternative MCP2515 module
Faster?!
Slightly modified:
Look at:mcp2515.c

Reduced to the max

Impressum: