topic Re: S32K Flexcan can continuous send data in S32K

S32K Flexcan can continuous send data

xiabin — Fri, 08 Nov 2019 06:22:12 GMT

I use S32K evb to send can message；when I use can continuous send like this question；

how to program to let Flexcan can continuous send data on s32ds.

if(FLEXCAN_DRV_GetTransferStatus(INST_CANCOM1, TX_MAILBOX) == STATUS_SUCCESS)
{
SendCANData(TX_MAILBOX, TX_MSG_ID, &ledRequested, 1);
}

The sending rate is very slow, and only 5 frames can be sent every 1 s.

The project is on the attachment. Where is the problem?

Re: S32K Flexcan can continuous send data

PetrS — Tue, 12 Nov 2019 17:30:58 GMT

Hi,

I tested this example with PCAN tool and see message sent each cca 150us.

This I think confirms theoretical assumption.

BR, Petr

Re: S32K Flexcan can continuous send data

xiabin — Thu, 14 Nov 2019 06:21:32 GMT

1 What is the state of J108 and 109 ?

How much voltage is Vbat?

Re: S32K Flexcan can continuous send data

PetrS — Thu, 14 Nov 2019 08:57:54 GMT

J108/J109 are placed and Vbat is 12V.

BR, Petr

Re: S32K Flexcan can continuous send data

xiabin — Sun, 17 Nov 2019 03:23:10 GMT

thank you！

The reason for the error is that I used vbat 5v。

I have another question: How many send mailboxes are suitable for not dropping frames? for example, I need to send 3 messages, each message period is 10ms.

Re: S32K Flexcan can continuous send data

PetrS — Mon, 18 Nov 2019 07:07:23 GMT

Hi,

once the MB is prepared for transmission, that is the CODE is written with 0xC, the MB participates in arbitration and the message is sent on the first opportunity window, when module sees a bus free.

So you can have several MBs prepared (in your case 3) for TX and those will be transmitted based on priority checked during arbitration.

BR, Petr