CAN can't be used on development board DEVKIT-S12XE

[zoejiang]

Hello,

I have bought two DEVKIT-S12XE development boards. Quick start package also download from web side.

Connect two boards as document 'DEVKIT-S12XE Lab Examples and Board Overview', page 6. Download the software in folder 'Lav4_CAN_S12XE ' into one board, and simulate in the other board.

Can bus can't be connected successfully between two boards.

Can signal can't be read by oscilloscope.

[aaronlee]

Do you mount 0 ohm resistor to R94?

[danielmartynek]

Hi,

How do you supply the boards? I think there is a short R94 – C17.

Are you sure both MCUs are running? Have you tried debugging it?

Regards,

Daniel

[zoejiang]

Yes, I did.

R94 has already been connected by a jumper.

Both boards are running.

Every time I tried I downloaded software both.

Voltage between CAN_H and GND is 0.33V, CAN_L and GND is also the same.

I also measured the voltage between Pin105 and GND , Pin104 and GND, both of them are 4.7v.

I also debugged it, the chip running smoothly.

Main function has been changed to send signal non stopped, but the signal still can't be caught by oscilloscope.

[danielmartynek]

Hi,

I have downloaded the example code without any modification into DEVKIT S12XE (we have only one board) and measured:

TXCAN0 (PT17)

and the on CAN_H/L (both open)

  /* Creation of CAN frame */
  id = 0x50;                         /*  Message id               */
  data_send = 0x01;           /*  Data to be send        */
  SendFrame_CAN(id,&data_send, 1);

In idle state, you should have a recessive level 2,5V on both CAN_H/L.

Are you sure there is no short on the boards after your soldering?

Regards,

Daniel

[zoejiang]

Hello,

Thank you for your reply.

Hard ware engineer and I tried it again. And we found TP13( port 5V-3)  is always 0V during software running. We checked the signal of SPI set in soft ware.  But we still have no idea.

Can you give me an e-mail about the software you tried?

Or give me some information about how to make TP13 5V?

[danielmartynek]

Hello,

I use the example code from DEVKIT-S12XE page.

DEVKIT-S12XE Quick Start Package/…/LAB4_CAN_S12XE

Is the System Basis Chip MCZ33903 supplied (PT2 = 12V)?

Have you tried running only one board as I did?

Does it mean that you have the same problem on both boards?

Regards,

Daniel

[zoejiang]

Thank you for your help.

Hardware engineer and I finally find we used the wrong power.

Now the problem is solved.

[christianhdz]

Hi, what is the correct way to power it? I tried using the SWUSB-VDD jumper, since I download the SW using the USB port, but also I need to power the LIN terminal... just VBAT(12V on the LIN pin2,  otherwise it would not communicate on CAN.

[danielmartynek]

Hi,

You can power the S12XE MCU via the USB (5V). But you need 12V (VBAT, J9, J8, J12) for MCZ33903CD (SBC) which contains CAN, LIN transceivers and power regulators. In this case, you can supply the S12XE (VDD) from P5V0_SBC (J13).

Regards,

Daniel

[tuandongvt]

Dear Daniel, Zoe Jiang,

I meet the same problem, i solder short R94,  connect jumper j13.2 and j13.3
CANH/LOW is 0V, 
TP2 is 5V
TP13 is 0V
only user power supply J9 is 5V.
follow you I need to push12V in J9?
Please help me,

[tuandongvt]

I known problem. I need to connect 12V connect with J9. Then problem is solved.