ESP32-OpenLIN

open-LIN/open-LIN-c implementation in ESP32.

Introduction

This project implements hardware abstraction APIs of open-LIN-c in ESP32 based on CW-B-W/ESP32-SoftwareLIN.

Besides of the implementation, there are simple examples to illustrate how to use open-LIN-c.

Features

• Send / Receive LIN bus frames on both LIN master and LIN slave
• Autobaud detection is supported by LIN slave

Quick start guide

1. Use VS Code with extension PlatformIO to open the project folder
2. Build and upload the ESP32 firmware with PlatformIO
   • If this device is acting as a LIN master, copy the examples/master.cpp to src/
   • If this device is acting as a LIN slave, copy the examples/slave.cpp to src/
3. Connect the UART pins of the ESP32 LIN master and ESP32 LIN slave

How to use

To send periodic frames

On Master

In examples/master.cpp, master_frame_table is used to store the periodic frames information. open-LIN-c keeps iterating through the table and send each frame itme.
Refer to

ESP32-openLIN/examples/master.cpp

Lines 44 to 47 in 677470a

	t_master_frame_table_item master_frame_table[] = {
	{10, 0, {0x02, OPEN_LIN_FRAME_TYPE_TRANSMIT, frame_data_length[0], master_data_buffer[0]}},
	{10, 0, {0x03, OPEN_LIN_FRAME_TYPE_RECEIVE, frame_data_length[1], master_data_buffer[1]}}
	};

On Slave

In examples/master.cpp, frame_slot is used to store the periodic frames information.
When a framed is received, open-LIN-c searches the received frame PID in the frame_slot and return the frame information if found.
Refer to

ESP32-openLIN/examples/slave.cpp

Lines 54 to 57 in 677470a

	open_lin_frame_slot_t frame_slot[] = {
	{0x02, OPEN_LIN_FRAME_TYPE_RECEIVE, frame_data_length[0], slave_data_buffer[0]},
	{0x03, OPEN_LIN_FRAME_TYPE_TRANSMIT, frame_data_length[1], slave_data_buffer[1]}
	};

Modify handlers

Master on received frame handler

In examples/master.cpp, function open_lin_master_dl_rx_callback is used to handle the frames received. Refer to

ESP32-openLIN/examples/master.cpp

Lines 84 to 91 in 677470a

	void open_lin_master_dl_rx_callback(open_lin_frame_slot_t* slot)
	{
	Serial.printf("[open_lin_master_dl_rx_callback] PID=%d\n\t", (int)slot->pid);
	for (int i = 0; i < slot->data_length; ++i) {
	Serial.printf("0x%02X ", slot->data_ptr[i]);
	}
	Serial.printf("\n\n");
	}

Master on error handler

In examples/master.cpp, function open_lin_error_handler is used to handle the errors. Refer to

ESP32-openLIN/examples/master.cpp

Lines 93 to 153 in 677470a

	void open_lin_error_handler(t_open_lin_error error_code)
	{
	Serial.printf("[open_lin_error_handler] error_code = %d\n", (int)error_code);
	switch (error_code) {
	case OPEN_LIN_NO_ERROR:
	Serial.printf("\t%s\n", "OPEN_LIN_NO_ERROR");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_DATA_RX:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_DATA_RX");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_CHECKSUM:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_CHECKSUM");
	break;
	case OPEN_LIN_SLAVE_ERROR_PID_PARITY:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_PID_PARITY");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_SYNCH:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_SYNCH");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_BREAK:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_BREAK");
	break;
	case OPEN_LIN_SLAVE_ERROR_ID_NOT_FOUND:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_ID_NOT_FOUND");
	break;
	case OPEN_LIN_SLAVE_ERROR_HW_TX:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_HW_TX");
	break;
	case OPEN_LIN_MASTER_ERROR_CHECKSUM:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_CHECKSUM");
	break;
	case OPEN_LIN_MASTER_ERROR_HEADER_TX:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_HEADER_TX");
	break;
	case OPEN_LIN_MASTER_ERROR_DATA_TX:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_DATA_TX");
	break;
	case OPEN_LIN_MASTER_ERROR_DATA_RX:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_DATA_RX");
	break;
	case OPEN_LIN_MASTER_ERROR_DATA_RX_TIMEOUT:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_DATA_RX_TIMEOUT");
	break;
	default:
	assert(0);
	}
	}

Slave on received frame handler

In examples/slave.cpp, function open_lin_on_rx_frame is used to handle the frames received. Refer to

ESP32-openLIN/examples/slave.cpp

Lines 115 to 122 in 677470a

	void open_lin_on_rx_frame(open_lin_frame_slot_t *slot)
	{
	Serial.printf("[open_lin_on_rx_frame] PID=%d\n\t", (int)slot->pid);
	for (int i = 0; i < slot->data_length; ++i) {
	Serial.printf("0x%02X ", slot->data_ptr[i]);
	}
	Serial.printf("\n\n");
	}

Slave on error handler

In examples/slave.cpp, function open_lin_error_handler is used to handle the errors. Refer to

ESP32-openLIN/examples/slave.cpp

Lines 124 to 185 in 677470a

	void open_lin_error_handler(t_open_lin_error error_code)
	{
	Serial.printf("[open_lin_error_handler] error_code = %d\n", (int)error_code);
	switch (error_code) {
	case OPEN_LIN_NO_ERROR:
	Serial.printf("\t%s\n", "OPEN_LIN_NO_ERROR");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_DATA_RX:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_DATA_RX");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_CHECKSUM:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_CHECKSUM");
	break;
	case OPEN_LIN_SLAVE_ERROR_PID_PARITY:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_PID_PARITY");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_SYNCH:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_SYNCH");
	break;
	case OPEN_LIN_SLAVE_ERROR_INVALID_BREAK:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_INVALID_BREAK");
	break;
	case OPEN_LIN_SLAVE_ERROR_ID_NOT_FOUND:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_ID_NOT_FOUND");
	break;
	case OPEN_LIN_SLAVE_ERROR_HW_TX:
	Serial.printf("\t%s\n", "OPEN_LIN_SLAVE_ERROR_HW_TX");
	break;
	case OPEN_LIN_MASTER_ERROR_CHECKSUM:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_CHECKSUM");
	break;
	case OPEN_LIN_MASTER_ERROR_HEADER_TX:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_HEADER_TX");
	break;
	case OPEN_LIN_MASTER_ERROR_DATA_TX:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_DATA_TX");
	break;
	case OPEN_LIN_MASTER_ERROR_DATA_RX:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_DATA_RX");
	break;
	case OPEN_LIN_MASTER_ERROR_DATA_RX_TIMEOUT:
	Serial.printf("\t%s\n", "OPEN_LIN_MASTER_ERROR_DATA_RX_TIMEOUT");
	break;
	default:
	assert(0);
	}
	Serial.println("\n");
	}

Enable/Disable autobaud for LIN slave

In examples/slave.cpp, if LIN_AUTOBAUD is defined, autobaud is enabled, otherwise autobaud is disabled. Refer to

ESP32-openLIN/examples/slave.cpp

Line 35 in 677470a

#define LIN_AUTOBAUD

Testing - Microchip LIN Serial Analyzer

This project was tested with Microchip LIN Serial Analyzer and NXP TJA1021 module.
(Sleep was not used in this test)

Connection

ESP32 as Master, LIN Analyzer as Slave

Setup

1. Use examples/master.cpp to do this test.
2. Open LIN Serial Analyzer Debug Tool
3. Hold ESP32 reset button (Don't release now)
4. Connect Debug Tool with LIN Serial Analyzer
5. Choose to use Enhanced Checksum Type in Debug Tool
6. Setup Slave Response in Debug Tool
7. Select the responses and click Add Slave Response Buffer
8. Release ESP32 reset button
9. LIN frames should be detected and shown on the screen

Result

Compared with the result in logic analyzer

ESP32 as Slave, LIN Analyzer as Master

Setup

1. Use examples/slave.cpp to do this test.
2. Open LIN Serial Analyzer Debug Tool
3. Connect Debug Tool with LIN Serial Analyzer
4. Choose to use Enhanced Checksum Type in Debug Tool
5. Setup Master frames in Debug Tool
6. Select the two frames and click Send Continuous
7. LIN frames should be detected and shown on the screen

Result

Compared with the result in logic analyzer

Testing - Vector VN1611

This project was also tested with VN1611.
We can take advantages of Vector XL Driver Library to test it with VN1611.