topic Re: CAN configuration with RTD/EB tresos for Freemaster in FreeMASTER

CAN configuration with RTD/EB tresos for Freemaster

sobo — Fri, 29 Aug 2025 08:55:00 GMT

Hello,

we are using a S32K358 with RTD 4.0.0 and EB tresos for configuration.
we are using Freemaster over UART without problem.

Now we want to use Freemaster over CAN.
The step I try with the option FMSTR_POLL_DRIVEN and FMSTR_DEBUG_TX.

The FLEXCAN1 clock is enable using EB tresos config , DIO are configure using EB Tresos.

I also configure the CAN controller with EB TResos.(250 Kb)

but I can't see the Debug frame on CAN
I'm not sure I have configure the CAN properly, we also use the FLEXCAN 0 for other purpose.
I disable CanRxFifo

Do someone have a example of CAN configuration ?

Sophie

Re: CAN configuration with RTD/EB tresos for Freemaster

sobo — Fri, 29 Aug 2025 10:12:23 GMT

How do I need to configure

/* Select RX and TX FlexCAN Message buffers */
#define FMSTR_FLEXCAN_TXMB 1
#define FMSTR_FLEXCAN_RXMB 0

with EB tresos Hardware object configure as :

Sophie

Re: CAN configuration with RTD/EB tresos for Freemaster

iulian_stan — Fri, 29 Aug 2025 12:32:47 GMT

Hi Sophie,

You do not need to configure the RX and TX buffers in EB. Only basic CAN driver configuration is required.

FreeMASTER will set messages IDs for RX (FMSTR_CAN_CMDID) and TX (FMSTR_CAN_RESPID) into the message buffers corresponding to those macros - FMSTR_FLEXCAN_RXMB and FMSTR_FLEXCAN_TXMB respectively.

Btw, are you able to send & receive standard messages (non FreeMASTER) ? As far as I know some S32K358 boards come with a secure CAN transceiver that requires additional configuration.

Iulian

Re: CAN configuration with RTD/EB tresos for Freemaster

sobo — Fri, 29 Aug 2025 12:57:55 GMT

Hi Iulian,

For the board we use our own hardware with a "normal" transceiver.
I will check if the HW is ok, but I would like to check the software configuration first.

So I need to remove hardware object from tresos and set
#define FMSTR_FLEXCAN_TXMB 0
#define FMSTR_FLEXCAN_RXMB 1

Sophie

Re: CAN configuration with RTD/EB tresos for Freemaster

iulian_stan — Fri, 29 Aug 2025 14:36:43 GMT

If my understanding is correct, EB Hardware are used by the RTD API to send/receive CAN messages, if so - they won't be used by FreeMASTER calls, but to avoid confusion I would remove them.

On the FreeMASTER configuration side (freemaster_cfg.h) select the CAN transport and set message buffer IDs:

// Select communication interface #define FMSTR_TRANSPORT FMSTR_CAN // Use can transport layer #define FMSTR_CAN_DRV FMSTR_CAN_S32_FLEXCAN // Use can driver for FLEXCAN /* Select RX and TX FlexCAN Message buffers */ #define FMSTR_FLEXCAN_TXMB 0 #define FMSTR_FLEXCAN_RXMB 1

Additionally, you need to set CAN base addres before calling FMSTR_Init
either via FMSTR_CanSetBaseAddress function call

/* Set FreeMASTER can base address */ FMSTR_CanSetBaseAddress((FMSTR_ADDR)0x40304000); /* Initialize FreeMASTER */ FMSTR_Init();

or via macro definition in the same configuration header file:

#define FMSTR_CAN_BASE 0x40304000

Re: CAN configuration with RTD/EB tresos for Freemaster

sobo — Mon, 01 Sep 2025 13:18:47 GMT

Thanks Iulian.

I try the software on another board, and it's works

Sophie

Re: CAN configuration with RTD/EB tresos for Freemaster

gzleng — Thu, 15 Jan 2026 02:36:25 GMT

Hi, would you please elaborate: "Only basic CAN driver configuration is required"? as far as i can see, there at least needs to config the pins, enable (and configure?) the clocks, hook up the interrup (directly or indirectly to FMSTR_can_isr??), configure the flexCan_43. but is it needed to config the hardwareobject or CANIF ? please help clarify.

Re: CAN configuration with RTD/EB tresos for Freemaster

iulian_stan — Thu, 15 Jan 2026 17:07:59 GMT

Hi @gzleng,

FreeMASTER Driver has an optimistic approach when it tries to use the CAN peripheral.
- It uses the CAN base address and operates directly with the registers to send/receive data.
- It does not verify whether it is enabled nor properly configured

It is expected that the developer performs the bare minimum configurations required to make the peripheral usable. It includes:
- Enabling the clocking for the used CAN instance
- Enabling and configuring CAN instance (Can_43_FLEXCAN should be sufficient, FreeMASTER does not use AUTOSAR's service layer → CanIf is not needed for FreeMASTER)
- Configuring the pins for the used CAN Instance

These configurations will allow you to use FreeMASTER Driver in polling mode. For interrupt mode, one more configuration is required:
- Configure the interrupt controller (enable CAN interrupt, and assign FMSTR_CanIsr as interrupt handler)

Hope it helps

Re: CAN configuration with RTD/EB tresos for Freemaster

gzleng — Thu, 15 Jan 2026 20:02:50 GMT

thanks Stan

after configuring one Transmit, one Receive Hardware Object in the EB, now the MB works. but i'm running into another issue with the host PC side: the ping is successful but the communication wizard still greys out so it cannot be finished. Attempting to configure the connection string in the Options dialog leads to a "the plugin configuration dialog failed, Try to specify the connection string manually" error. similar to another post from Jan 9th. i don't use mbdt and the driver is the 1.5.0

Re: CAN configuration with RTD/EB tresos for Freemaster

iulian_stan — Fri, 16 Jan 2026 08:30:43 GMT

Just to be sure - did you try Michal's suggestion ?

Re: CAN configuration with RTD/EB tresos for Freemaster

BillWen — Tue, 27 Jan 2026 01:40:22 GMT

Hi @iulian_stan:
I have the same question about Freemaster over Can bus.
My project is based on NXP HVBMS_Integration_Project_0_8_0 with RTD 3.0.0, we use LPUART to communicate Freemaster originally, and we want to change it to can bus.
According to your answer, I have few question.
1. Do I need create FMSTR_CAN_S32_FLEXCAN by myself? I can't find this define inside my project.
2. About the following setting, I already config Can hardwareobject in MCAL setting. I need set this define according to my MCAL setting about hardwareobject or how to set this ?
/* Select RX and TX FlexCAN Message buffers */
#define FMSTR_FLEXCAN_TXMB 0 (?)
#define FMSTR_FLEXCAN_RXMB 1 (?)
3. I can't find this "FMSTR_CanSetBaseAddress" API inside my source code, do I need add other source code?

The following is my setting right now :

#define FMSTR_PLATFORM_S32 1 // Automotive S32 platform (see freemaster.h for list of all supported platforms)

#define FMSTR_DEMO_ENOUGH_ROM 1 // Platform has enough ROM to show most of the FreeMASTER features
#define FMSTR_DEMO_LARGE_ROM 1 // Platform has large ROM enough to store the extended data structures used in FreeMASTER demo
#define FMSTR_DEMO_SUPPORT_I64 1 // support for long long type
#define FMSTR_DEMO_SUPPORT_FLT 1 // support for float type
#define FMSTR_DEMO_SUPPORT_DBL 1 // support for double type
// Enable/Disable FreeMASTER support as a whole
#define FMSTR_DISABLE 0 // To disable all FreeMASTER functionalities

// Select interrupt or poll-driven serial communication
#define FMSTR_LONG_INTR 0 // Complete message processing in interrupt
#define FMSTR_SHORT_INTR 1 // Queuing done in interrupt
#define FMSTR_POLL_DRIVEN 0 // No interrupt needed, polling only

// Select communication interface
#define FMSTR_TRANSPORT FMSTR_SERIAL // Use serial transport layer
#define FMSTR_SERIAL_DRV FMSTR_SERIAL_S32K3XX_LPUART // Use serial driver for UART

// Input/output communication buffer size
#define FMSTR_COMM_BUFFER_SIZE 0 // Set to 0 for "automatic"

// Receive FIFO queue size (use with FMSTR_SHORT_INTR only)
#define FMSTR_COMM_RQUEUE_SIZE 32 // Set to 0 for "default"

Thanks
BR, BillWen