Vida CEM swapping

Post by **vtl** » 25 Apr 2021, 09:06

CAN only opens after K-Line keep alive message sent on those earlier P2s.

5ft24 · Post by **5ft24** » 25 Apr 2021, 12:48

RickHaleParker wrote: 23 Apr 2021, 21:47
RickHaleParker wrote: 13 Apr 2021, 15:56
T5Luke wrote: 13 Apr 2021, 03:03 For me it looks like to much noise on the can bus, i dont trust this 3,3V transceivers.
Ordered some 3V - 5V CAN Transceivers based on the NXP TJA1051. Should be here next week. I'll run them at 5V and see if it makes a difference. Will post the log with no other changes in test conditions.
No change in results.

What CAN transceivers are the rest of you using and how is the performance?

When the weather warms up. I'll go to the local yard and get some CEMs so I can do bench testing.

Did check the 5V line for noise. It only 40 mv PP. That is less then 0.8%.
Vertical 5mv/ division. Cycle repetition time 1.35 ms.

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Rick, I am using the Texas Instruments SN65HVD230DR. Running 3.3V per VTL's GitHub.
Got them from Mouser Electronics for $2.54 each

5ft24 · Post by **5ft24** » 25 Apr 2021, 13:00

vtl wrote: 24 Apr 2021, 07:00 The original idea was to detect latency as low as like 6 cycles of MCU base frequency (30 MHz for Renesas). No interrupts in the world would allow doing this, other than on CPU clocked at like 10+ GHz. Later it turned out the CAN bus cycle is always aligned at CAN clock frequency, not MCU clock. So such high the precision is not required in that case.

I've tried reading directly, but it didn't help, because the initial algorithm was misfit for the task.

Agree with T5Luke, a counterfeit $11.xx Saleae Logic clone is enough for the task. I use it all the time. When I become rich I'll buy a real one, just as a thanks to Saleae team.

Where can I get one of these Saleae logic clones? Went to the Wiki and all the links are in German and state the product can't be found...

5ft24 · Post by **5ft24** » 25 Apr 2021, 13:08

Nevermind. All the links were for the MCU123 brand... Found a generic clone says is compatible with Sigrok on Amazon for 9 bucks

Post by **vtl** » 25 Apr 2021, 13:35

Search on eBay or Ali.

Post by **RickHaleParker** » 25 Apr 2021, 22:58

vtl wrote: 25 Apr 2021, 13:35 Search on eBay or Ali.

I ordered a QiXin USB Logic Analyzer 24MHz 8 Channel UART IIC SPI. Comes with a Ferrite Ring USB Cable, 12 x 6-color ribbon cable and test hooks. $17.86 free shipping.

QiXin is not on the sigrok supported hardware list but is listed a sigrok supported by the vendor. QiXin is either a rebranded VKTECH or both get the hardware from the same generic manufacture. They look identical in the pictures.

Wondering why they did not use the Six Tertiary Colors in addition to the Three Primary Colors and Three Secondary Colors to get a different color for each line.

Post by **RickHaleParker** » 26 Apr 2021, 01:30

5ft24 wrote: 25 Apr 2021, 12:48 Rick, I am using the Texas Instruments SN65HVD230DR. Running 3.3V per VTL's GitHub.
Got them from Mouser Electronics for $2.54 each

Same 3.3v CAN transceivers I was using before I switched to NXP TJA1051T/3 at 5V. No difference in results.

alfons38 · Post by **alfons38** » 26 Apr 2021, 03:25

Anyone can sell finish kit with software

MaxDenisov · Post by **MaxDenisov** » 26 Apr 2021, 04:02

vtl wrote: 25 Apr 2021, 08:10
MaxDenisov wrote: 24 Apr 2021, 12:57 @vtl I am working on new pc/hardware design. Please let me know if you are interesting in spare pcb/device
It also need a driver for K-line, for earlier P2s. I used mc33290d connected to serial port 3.

Made a small correction, k-Line added and -> 12- 5V:

Post by **vtl** » 26 Apr 2021, 04:50

K-Line TX to TX3 (pin 14).

Also this chip is obsolete (out of production), you may want to replace it with mc33290d.