Solved
HardFault (CANopenNodeSTM32, traditional CAN - not FDCAN, FreeRTOS, STM32L452RE)
The author of this how to get CANopenNodeSTM32 working video is very good (The length of the video is 3:31:33; The part that is pertinent to this post 57:05 - 1:18:22). Unfortunately, this video targets FDCAN (but I don't have this available; my chip just supports plain CAN) and this video also targets bare metal (but I don't have this available; FreeRTOS is what I am using). I tried to follow all of the author's steps but was unable to. When I ran I got a HardFault with the CAN node never even coming online.
Executing this line is what causes the Hard fault
canopen_app_init(&canOpenNodeSTM32);
From the instructions in the video, there are numerous steps that are different between FDCAN and CAN and I don't know what the equivalent (plain) CAN steps are which I believe may be the root of the problem.
Under the "Parameter Settings" tab
- "FDCAN1" and "FDCAN2" are in the video at 1:00:55. Mine doesn't have these. Mine just has "CAN1"
- "Auto Retransmit" is in the video at 1:01:20. Mine doesn't have this. Nor do I see an equivalent setting.
- "Transmit Pause" is in the video at 1:01:22. Mine doesn't have this. Nor do I see an equivalent setting.
- "Frame Format" is in the video at 1:01:41. Mine doesn't have this. Nor do I see an equivalent setting.
- The bit timing settings ("Nominal Prescaler", "Nominal Time S...", "Nominal Time S..") are in the video at 1:04:25. Mine doesn't have quite the same. Mine is "Prescaler (for Time Quantum)", "Time Quanta in Bit Segment 1", "Time Quanta in Bit Segment 2". I set these to 40,12 Times, 4 Times respectively. The numbers that the presenter set his to are 32,13,2 respectively. His numbers were based on fields that he has that I don't have and so I am unclear as to whether it is comparing apples to apples or apples to oranges. I don't know if my numbers are correct.
- "Data Prescaler" is in the video at 1:04:36. Mine doesn't have this. Nor do I see an equivalent setting.
- "Data Time Seg1" is in the video at 1:04:36. Mine doesn't have this. Nor do I see an equivalent setting.
- "Data Time Seg2" is in the video at 1:04:36. Mine doesn't have this. Nor do I see an equivalent setting.
Under "NVIC Settings" tab
- "TIM16, FDCAN1_IT0 and FDCAN2_IT0 Interrupt" is in the video at 1:05:58. Mine doesn't have this.
- " TIM17, FDCAN1_IT1 and FDCAN2_IT1 Interrupt" is in the video at 1:05:58. Mine doesn't have this.
- Mine shows only the following
- "CAN1 TX interrupt"
- "CAN1 RX0 interrupt"
- "CAN1 RX1 interrupt"
- Note: I attempted to activate TIM16 on each of these to see what would happen and every time it disabled CAN on the pin; both the timer and CAN don't seem to be able to coexist.
Under Timers
- "TIM14" is in the video at 1:07:05. Mine doesn't have this. Nor do I see an equivalent.
Below is all of the 'CAN' related code per the author's recommendation on top of what was generated from the .ioc file. Note: this is specifically the FreeRTOS implementation not bare metal, since I don't have an option to run bare metal.
Notes:
- Double blank lines below means that I removed unreleated code/comments that was not 'CAN'. I removed this so anyone looking through will just see the 'CAN' related code. Maybe it will make it easier to spot an error (or multiple errors) that I made.
- The commented out lines that appear below resulted from me not being able to follow the author's steps - Because I don't have FDCAN; I just have CAN.
All code that I modified/added below is just in one file - main.c (.../App/main.c)
#include "CO_app_STM32.h"
osThreadId_t canOpenNodeTaskHandle;
const osThreadAttr_t canOpenNodeTask_attributes = {
.name = "task CAN",
.stack_size = 192,
.priority = (osPriority_t) osPriorityHigh,
};
static void MX_CAN1_Init(void);
void startCanOpenNodeTask(void *argument);
MX_CAN1_Init();
canOpenNodeTaskHandle = osThreadNew(startCanOpenNodeTask, NULL, &canOpenNodeTask_attributes);
static void MX_CAN1_Init(void)
{
hcan1.Instance = CAN1;
hcan1.Init.Prescaler = 40;
hcan1.Init.Mode = CAN_MODE_NORMAL;
hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_12TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_4TQ;
hcan1.Init.TimeTriggeredMode = DISABLE;
hcan1.Init.AutoBusOff = DISABLE;
hcan1.Init.AutoWakeUp = DISABLE;
hcan1.Init.AutoRetransmission = DISABLE;
hcan1.Init.ReceiveFifoLocked = DISABLE;
hcan1.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan1) != HAL_OK)
{
Error_Handler();
}
}
__attribute__((noreturn)) void startCanOpenNodeTask(void *argument)
{
CANopenNodeSTM32 canOpenNodeSTM32;
//canOpenNodeSTM32.CANHandle = &hfdcan1;
canOpenNodeSTM32.CANHandle = &hcan1;
// canOpenNodeSTM32.HWInitFunction = MX_FDCAN1_Init;
canOpenNodeSTM32.HWInitFunction = MX_CAN1_Init;
// canOpenNodeSTM32.timerHandle = &htim17;
canOpenNodeSTM32.desiredNodeID = 21;
// canOpenNodeSTM32.baudrate = 125;
canopen_app_init(&canOpenNodeSTM32); // Hard fault
// never makes it to here because the line above Hard faults
for(;;)
{
// it makes no difference what is in here yet, because a Hard fault occurs when executing the above line
}
}