EEVBLOG #444 - Data sheet read-along with Dave - Page 1
Forum section: electronics / general

author: PeteInTexas
author_rank: Frequent Contributor
timestamp: March 26, 2013, 03:48:04 am
content: I appreciate every video Dave puts out including this one but I dunno, I was really expecting at least an attempt to power it up.

author: c4757p
author_rank: Super Contributor
timestamp: March 26, 2013, 03:51:26 am
content: How? It's not like it would have done anything without being properly connected. Pretty sure all that would happen is the controller would sit there watching for activity on the CAN bus.

author: pickle9000
author_rank: Super Contributor
timestamp: March 26, 2013, 04:16:13 am
content: I don't know anything about CAN bus. Would there be any change if not connected to a working system?

author: PeteInTexas
author_rank: Frequent Contributor
timestamp: March 26, 2013, 04:29:40 am
content: Quote from: c4757p on March 26, 2013, 03:51:26 amThat recently reviewed Saleae logic analyzer was capable of comprehending a CAN bus. Hook her up see what she says on power up (I know nothing about CAN). The process of guessing which pins are what would have been entertaining. Maybe in a follow up video...

author: c4757p
author_rank: Super Contributor
timestamp: March 26, 2013, 04:45:21 am
content: I doubt it will say anything at all unless you transmit to it first.

author: EEVblog
author_rank: Unknown
timestamp: March 26, 2013, 08:19:41 am
content: Quote from: PeteInTexas on March 26, 2013, 03:48:04 amThis was shot as part of the mailbag before I went on holidays, I did not have time to power it up and play around with it.I asked if anyone had any info on the pinouts which would have been a useful starter to understand if it can output anything useful at all, before I wasted time on it.If you have any info to share, please do so and I'll power it up.Otherwise, my guess is that it would not have done anything useful at all. What do you expect to get out of it? I expect just some proprietary data over the CAN bus, or maybe nothing if it doesn't receive the right power-up/activate/speed CAN data from the car.Dave.

author: Anks
author_rank: Frequent Contributor
timestamp: March 26, 2013, 09:35:04 am
content: There was a demonstration on UK tv (Fifth gear) last night of a volvo a merc and a vw doin automatic breaking. As far as I know the Volvo uses this sort of thing plus a radar with the same chipset for its "city safe" system aswell as the system in there trucks. The other two car wernt that good but the Volvo system worked at 55mph If I remember right.A video for city safe.The same system in trucks.And it dosnt always work lol

author: peter.mitchell
author_rank: Super Contributor
timestamp: March 26, 2013, 10:29:50 am
content: something something brown pants

author: firewalker
author_rank: Super Contributor
timestamp: March 26, 2013, 11:06:18 am
content: Buy an Raspberry-Pi with the camera module install OpenTLD, train it, hook it to the braking system and you are ready. Automatic breaking system.Alexander.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: March 26, 2013, 11:46:44 am
content: 15:00 My guess would be that the chip is a balanced line driver or something of the sort, and/or that the black thing on the top side is a transformer.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: March 26, 2013, 12:01:01 pm
content: Quote from: nitro2k01 on March 26, 2013, 11:46:44 amLooks like a choke for the CAN bus lines and a biased split termination with actual termination resistors not visible or just simply the bus is not terminated there.

author: PeteInTexas
author_rank: Frequent Contributor
timestamp: March 26, 2013, 02:20:51 pm
content: Quote from: EEVblog on March 26, 2013, 08:19:41 amHere is a 10 pin can bus spec:http://www.interfacebus.com/Can_Bus_Connector_Pinout.html#bI see 12 pins on the device but I'm sure a closer look of the connector would help sort things out.I expect that it would try to talk to another device, like the braking system maybe or the audio system for that rumble strip effect to check if they are present on the bus. Maybe the video/snapshot is streamed to a more intelligent device for more processing at some interval or maybe continuously. A follow-up video along these lines would be interesting.

author: PeteInTexas
author_rank: Frequent Contributor
timestamp: March 26, 2013, 02:34:31 pm
content: Quote from: c4757p on March 26, 2013, 04:45:21 amIt can't do it all, its a good guess it will try to check on power up for another device on the bus that complete the system.

author: Rodville
author_rank: Contributor
timestamp: March 26, 2013, 09:30:56 pm
content: Quote from: EEVblog on March 26, 2013, 08:19:41 amCan you give me the Mobis part number off of it? If it is shared with KIA I might be able to get the schematic from KGIShttps://www.kiatechinfo.com/Index.asp

author: ConKbot
author_rank: Super Contributor
timestamp: March 27, 2013, 04:17:17 pm
content: I havent seen anyone mention this yet, though the videos may have shown it. The lane departure cameras typically go at the top of the windshield, in front of the mirror, hence the sleek shape of the front of it and the lack of waterproofing.

author: m0r
author_rank: Newbie
timestamp: March 27, 2013, 08:33:29 pm
content: I was quite surprised seeing the caps not being glued down. How high do the caps rise up from the pcb? I've heard of around 5mm as a maximum height for parts not being glued down in automotive use, those seem to be higher.Does anyone know where these devices are mounted on a car? I'd guess that it's close to the respective front wheels, probably inside/close to the wheel arch. The temperature range wouldn't be too bad in that case (around +85°C I'd guess). The seemingly rather poor water resistance could also attest to this. (*ConKbot already posted that they're usually mounted behind the windshield)Camera technology/infotainment is one of the main reasons for automotive ethernet. I would have guessed that it's just a camera->proprietary ethernet module sending data to a ECU with some more inputs (indicator on, steering direction, etc). Given the high level of these systems can have over a car ('assisting' steering and even braking) I doubt that this would be done on a single freescale controller.But being a part in use at one of the world's largest car makers it surely has been certified and tested to death.

author: hans
author_rank: Super Contributor
timestamp: March 27, 2013, 09:00:03 pm
content: Note that CAN is just another way of talking about a physical layer plus some can frames (similar to how ethernet mac + physical layers), but on top of that there are many protocols, like ISO-BUS or other protocol layers etc. I'm afraid these are often proprietary on it's own, and then there is the manufacturer which implements their own CAN messages / flow diagrams to communicate, connect devices onto the bus, handle error situations, etc.So my guess would be it's hard to get the data out, however it may be interesting to see what can frames would pass by from the device itself (I guess this device has to connect to another control unit on the bus).

author: PuterGeek
author_rank: Regular Contributor
timestamp: March 28, 2013, 03:40:22 am
content: CANbus as used in vehicles is pretty straight forward although two nodes are required to do anything. The protocol is typically J1939 or the ISO equivalent.A message packet has a 29 bit identifier and up to 8 bytes of data. Most messages are transmitted periodically but some are by request.The message format is well defined even for proprietary messages. The content of standard messages is in the standard but how the proprietary messages are used is entirely up to the manufacturer.I've done a lot of work over the past few years with J1939 and can probably tell you more than you would ever want to know.

author: GreggD
author_rank: Regular Contributor
timestamp: July 28, 2017, 03:16:48 pm
content: Dave glossed over this in the datasheet.This Qorivva microcontroller is unusual in that program flash/data flash/ sram are all error corrected.Have not seen this in a uP.