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by Zeta
Sat Feb 02, 2013 9:45 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI driver latency and a possible solution
Replies: 242
Views: 152899

Re: SPI driver latency and a possible solution

I feel it's very unreasonable to expect people who may buy this device to have to upgrade their kernel, etc. (lets face it - it's hard enough to get people to do apt-get update/upgrade without then asking them to do more upgrades to get a new kernel )-: What do you mean by buy this device ? Buy a R...
by Zeta
Sat Feb 02, 2013 1:55 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

A commit dated 2013-01-22, SHA1 91a3be5b2b783b930b2d7cdbf38283b613bce7d4 fixes something in drivers/spi/spi-bcm2708.c, which the SPI latency patch wants to modify. As this discussion is related to the SPI and not directly to the CAN, I continued the discussion in the corresponding forum, with a new...
by Zeta
Sat Feb 02, 2013 1:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI driver latency and a possible solution
Replies: 242
Views: 152899

Re: SPI driver latency and a possible solution

For those who tried to apply the patch since the end of January, you should have seen a problem. An update as been made to the kernel source, that give an error when trying to apply the patch: https://github.com/raspberrypi/linux/commit/91a3be5b2b783b930b2d7cdbf38283b613bce7d4 It seems that the comm...
by Zeta
Sat Feb 02, 2013 12:09 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

OK, it worked : your patch 1st, then the SPI latency one. You might want to write the SHA1 in your wiki page ? Will this SPI patch be merged in the kernel soon ? It seems like it is a major fix. Good to know I didn't miss something. I did not have a lot of time to work on it this week. I can only c...
by Zeta
Mon Jan 28, 2013 10:39 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello dplamp, Thanks ! I made it using the following git revision (on branch 3.6.y) : commit 523029f607564ab2080e83a3384feac4439b2b38 Merge: ff1c7e1 072e44f Author: popcornmix <popcornmix@gmail.com> Date: Tue Dec 4 23:06:01 2012 +0000 Merge commit 'v3.6.9' into rpi-3.6.y There may be something pushe...
by Zeta
Sun Jan 20, 2013 11:13 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Dear all, I'm back with a good news : I finally took some time to create a reference page on elinux.org for using the MCP2515 on the Raspberry Pi : http://elinux.org/RPi_CANBus There are still some things to add (like the bash commands to load needed modules or to check the status), but there is at ...
by Zeta
Mon Jan 14, 2013 7:31 pm
Forum: Other projects
Topic: CAN Interface
Replies: 103
Views: 110299

Re: CAN Interface

I guess I was too focused on the Raspberry Pi, which is not always involved. Yes, the part you are trying to find is only the CAN bus protocol for this specific car. This has nothing to do with the RaspberryPi. Maybe search more on car tuning forums, or sites like that, that have more car-related i...
by Zeta
Sun Jan 13, 2013 1:14 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Chris, I still intend to make a wiki page on eLinux.org, describing the steps I used to make it work. I wanted to finished my quick project (CAN to wireless UDP or TCP gateway) using it to be sure it really works. Maybe it can be the right time to create it, so that you can compare with what you did...
by Zeta
Sun Jan 13, 2013 11:55 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello Chris, http://www.mail-archive.com/socketcan-core@lists.berlios.de/msg01747.html This mail is more than 2 years old. If I look at the source of the linux_3.6.y branch for the raspberry Pi, it seems that all that is in that patch is already there (only checked the first 4/5 out of 8 patches). A...
by Zeta
Sat Jan 12, 2013 11:35 pm
Forum: Other projects
Topic: CAN Interface
Replies: 103
Views: 110299

Re: CAN Interface

Does anyone know where one can find the kind of things one could control with a Pi plugged into the CAN bus of a Volkswagen Golf ? Google is a good start: http://hackaday.com/2011/04/26/enhance-your-key-fob-via-can-bus-hacking/ I'm currently thinking of Cruise Control and maybe the infotainment scr...
by Zeta
Tue Jan 08, 2013 6:45 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI driver latency and a possible solution
Replies: 242
Views: 152899

Re: SPI driver latency and a possible solution

Hello Allan, You can find a lot of answer on the topic about the CAN controller : http://www.raspberrypi.org/phpBB3/viewtopic.php?f=44&t=7027 To use the patch of msperl, simply apply it like that : cd /opt/raspberrypi/linux_3.6.y wget http://www.raspberrypi.org/phpBB3/download/file.php?id=1492 -O sp...
by Zeta
Mon Jan 07, 2013 5:27 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello Chris, I made a quick try today, with the mcp251x driver (as the other one doesn't support Loopback), kernel 3.6.y, and the command you taught me: ip link set can0 type can loopback on It seems Ok, but as you can see below, the interface is "STOPPED": 4: can0: <NOARP,ECHO> mtu 16 qdisc noop st...
by Zeta
Fri Jan 04, 2013 12:21 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

The Controller is set to loop back mode over a register of the mcp 1525 through its driver (mcp251x). Below you may find the respective parts of the driver: ... # define CANCTRL_REQOP_LOOPBACK 0x40 ... if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { /* Put device into loopback mode */ mcp251x_wri...
by Zeta
Wed Jan 02, 2013 9:08 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

I wish all of you a happy new year. Zeta, thanks for the reply, got it. Hello Chris, Happy new year too ! I am working in loopback mode, that means internal transmission between receive and transmit buffer and ACK Bit ignored. I still have a lot to learn about the CAN bus and its driver. For exampl...
by Zeta
Tue Dec 25, 2012 9:32 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello Chris, Version 1 is damaged and everything seems to be working fine (except the CAN itself (ERROR-Active)) on MCP2515 side. Take care of the misleading "ERROR-Active" Flag. It is not a problem. From the MCP2515 data-sheet (http://ww1.microchip.com/downloads/en/devicedoc/21801d.pdf) , you can r...
by Zeta
Wed Dec 19, 2012 11:36 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello Martin, You have interesting results here. It makes me think I did not precise that my results were with standard CAN id (11 bits) and message length of 8 bytes of data. About the driver itself, and making it reach the kernel, you may be interested by the following message (and the whole threa...
by Zeta
Mon Dec 17, 2012 10:50 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Removing this one patch in 3.6.y does not resolve the issue. There seems to be a bigger issue with other changes to the interrupt infrastructure... This will possibly mean a modification of the mcp251x driver is really needed... Martin I don't have your experience when playing with the drivers in L...
by Zeta
Mon Dec 17, 2012 3:09 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Martin, Gerd, Here are the results of my last tests, where I sent n*1000 frames at maximum speed (so bus load close to 100%), with CPU idle (nothing more than SSH and candump) : - Kernel 3.6.y, Asynchronous MCP2515 driver, standard SPI driver * @125kbps : no frame lost, no overrun * @500kbps : only ...
by Zeta
Sun Dec 16, 2012 1:11 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

do you use the modified SPI module from Martin ? hello gerd, i'm not using it yet, but it is on my todo list. I'm trying to make it works step per step, so that it's easier to find where are the problems if any. So far, the toolchain, the 3.6.y kernel and the asynchronous mcp2515 driver seems ok. I...
by Zeta
Fri Dec 14, 2012 7:23 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello, I had not a lot of time today, but tested quickly the "asynchronous MCP2515" driver (http://clientes.netvisao.pt/anbadeol/mcp2515.html), with the 3.6.y kernel. I launched it, connect it to the same system as the other time, and seeing that it seems to work, I let it some time to see if it fin...
by Zeta
Thu Dec 13, 2012 8:11 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello Martin, and thanks for your answer. It helps me a lot ! I have seen the behaviour of the mcp2515 driver getting "non responsive" only with the 3.6.y kernel, where I had to use the ONE_SHOT to get it working in the first place - the 3.6.y kernel will not let you do it otherwise. I said a mistak...
by Zeta
Wed Dec 12, 2012 10:29 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: CAN controller
Replies: 816
Views: 376693

Re: CAN controller

Hello to all ! Thanks for your work on the MCP2515 controller. I have made a small test board with the couple MCP2515/MCP2551, cross-compiled a kernel (from 3.6.y branch) with the standard MCP251x driver (configured at 20MHz), put all on a raspbian SDcard, and made some quick tests. I have basically...

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