topic Re: TWR K70F120M and FlexCAN example in Kinetis Microcontrollers

TWR K70F120M and FlexCAN example

raulmoneo — Thu, 30 Jan 2014 11:41:40 GMT

Please need some help with FlexCAN example in TWR K70F120M.

This example requires two Towers, At the beginning I only had one so I've set FlexCAN in LOOPBACK mode and It seems to work well, I saw the interrupt each second.

Now I have a CAN emulator and I've set it to listen without any filter and I've set back FlexCAN example to NORMAL mode but I don't see any traffic in the bus.

I've checked the CAN emulator listen ok at the same baude rate with other CAN device.

TWR-SER J5 settings:

1-2 close

3-4 open

5-6 close

7-8 close

9-10 close

J4 open

Someone have run FlexCAN example in TWR K70F120M? any advice?

Thanks in advance

Raúl

Re: TWR K70F120M and FlexCAN example

santiago_gonzal — Thu, 30 Jan 2014 16:18:27 GMT

Hello Raul,

I have tested the MQX example project of FlexCAN in the past, and it worked between two TWR boards without any problem.

Could you check with a Scope if the output pins of the MCU (CanRX and CanTX) are showing activity?

Do you know if you CAN listener adds a end of line resistance?

Regards,

Santiago

Re: TWR K70F120M and FlexCAN example

raulmoneo — Tue, 04 Feb 2014 14:25:23 GMT

Hi Santiago,

Thanks for your reply.

There is no any activity in the bus. CAN_H and CAN_L both stay in high level.

I've connected emulator to other CAN devices and it works I guest it has end of line resistance but not sure.
I've run the example connecting the tower to this circuit I found in the forum but I don't see activity in the scope.

CAN_H ________________

| |

| _|_

----- 47nF |__| 56Ohm

----- |

|___ | |________|

| | | 0.1uF |

| |

| _|_

----- 47nF |__| 56Ohm

----- |

CAN_L __|_____________|

Any suggestion?

Thanks in advance.

Raul

Re: TWR K70F120M and FlexCAN example

santiago_gonzal — Tue, 04 Feb 2014 16:19:58 GMT

Hi Raul,

Please, check the CAN RX and CAN TX signals from the MCU. You can have access to them using the through hole connectors in the outside part of the TWR-Elevators. The CAN RX and TX are the B41 and B42 pins.

If you don't see activity on the pins I will try with my own board. Can you tell me/share what project are you exactly using?

Regards,

Santiago

Re: Re: TWR K70F120M and FlexCAN example

raulmoneo — Tue, 04 Feb 2014 17:07:31 GMT

Hi,

Yes, I did it.

When I generate traffic with the emulator I see traffic in B41 but interrupt don't happen.

The can example (TX task) sends a frame each second but nothing appears in B42.

I attach here the project. I created a project based on the example of Flexcan. The source code is taken from "MQX_DIR\mqx\examples\can\flexcan\"

Thanks for your help.

Raúl

Re: TWR K70F120M and FlexCAN example

raulmoneo — Wed, 12 Feb 2014 16:01:27 GMT

Hi,

I got a second tower K70F120M.

I created, built and downloaded FlexCAN example with NODE 1 and NODE 2. I've connected Pin CAN_H with CAN_H and CAN_L with CAN_L.

I don't see any bus activity.

I've debugged driver, checking CAN registers and It seems to follow the configuration steps that "FlexCAN_training_material.pdf" says.

Any advice?

Thanks.

Re: TWR K70F120M and FlexCAN example

raulmoneo — Fri, 14 Feb 2014 09:08:17 GMT

The answer here

https://community.freescale.com/thread/317691