DoCAN UDS Server Demo

There is an example implementation of UDS server available in apps folder. In this implementation, a model ECU is created to mimic various features.

Following DTC test codes are available in the example:

Example DTC Codes
DTC Record	Size	Description
0x12	4 Bytes	CAN transmit counter
0x34	4 Bytes	CAN receive counter
0x56	1 Byte	AIR Bag status

Following Data IDs are available in the example:

Supported Data IDs
Data ID	Size	Read/Write	Description
0x0101	1 Byte	Read Only	Battery Level from 0 to 100
0x0105	1 Byte	Read Only	Speed Value from 0 to 200
0x2109	1 Byte	Read Write	Drive Mode Value from 0 to 4
0x4567	1 Byte	Read Write	Gear Value from -1 to 5
0x7890	1 Byte	Read Write	Self Check start from 0 to 1
0xABCD	4 Bytes	Read Only	Trip A Value from 0 to 800000
0xF190	21 bytes	Read Only	VIN Number value “Hello From UDS Server”
0xF200	2 Bytes	Read Only	RPM Value from 0 to 8000
0xF205	1 Byte	Read Write	Left Indicator On from 0 to 1

Scaling data is supported for only one id : 0x0105 with a value of [0x01, 0x95, 0x00, 0xE0, 0x4B, 0x00, 0x1E, 0xA1, 0x30].

A memory region of size 1500 bytes is defined starting at address 0x20001000 for performing read/write memory by address operations. This is implemented via a simple array.

One routine is defined at 0x4321 to blink a LED given number of times.

While all the implementation are meant to be tested without any underlying hardware, enabling a compile time macro PLATFORM_TEST_SUPPORT, will call some function that can be used to certain real functionalities such as LED on, soft reset etc.

Diagnostic Session Control (0x10) service

The example implementation just prints out the session type requested and returns a positive response.

ECU Reset (0x11) service

The type of request is just printed. For Enable Rapid power shutdown mode, the power down timing is returned as 5. But no other actions taken. platform_sw_reset is called for Soft reset request in PLATFORM_TEST_SUPPORT mode.

Clear Diagnostic Information (0x14) Service

The DTC group code is printed out. In PLATFORM_TEST_SUPPORT mode, CAN transmit/receive counters are cleared.

Read DTC Information (0x19) Service

Specific DTC record IDs can be read using RS_IS14229_READ_DTC_REPORT_DTC_STORED_DATA_BY_RECORD_NUMBER sub-function code. Others are not supported. With 0xFF, all the 3 DTC records can be read in a single shot. In PLATFORM_TEST_SUPPORT mode, CAN transmit/receive counters and Air bag information from a GPIO are used.

Read Data By ID (0x22) service

Few Data IDs are supported in the demo where many of them are automatically incrementing so that it can be read to find the differences.

Read Memory By Address (0x23) service

Data can be read from address 0x20001000 using this service for up to 1500 bytes.

Read Scaling Data By Identifier (0x24) service

Scaling data can be read for Vehicle speed data ID

Security Access (0x27) service

Initiates security access on the server. To be elaborated.

Communication Control (0x28) service

Simply prints the control type information received from the tester. Few global variables updated but not used.

Read Data By Periodic Identifier (0x2A) service

Yet to be implemented in the example.

Write Data By Identifier (0x2E) service

Data ID specified as Read/Write are allowed to be written

Input Output Control By Identifier (0x2F) service

Only prints are supported with fixed response value.

Routine Control (0x31) service

A single routine to blink a LED is supported. When starting the routine, number of blinks to be done can be passed. The same can be stopped and or status queried.

RequestDownload (0x34) service

The example allows the client to download a data and optionally store it in local file system as a file.

TransferData (0x36) service

The example allows the client to transfer data.

RequestTransferExit (0x37) service

The example allows the client to complete data transfer.

Write Memory By Address (0x3D) service

Data can be written from address 0x20001000 using this service for up to 1500 bytes.

Tester Present (0x3E) service

A simple print can be seen on receiving this service request.

Access Timing Parameter (0x83) service

Simple prints can be seen on receiving this service request.

SecuredDataTransmission (0x84) service

The example simply returns one’s complement of the given input.

Control DTC Setting (0x85) service

The example simply prints the given input.

Link Control (0x87) service

The example simply prints the given input and returns a fixed parameter value of 0x123456.

Refer to the UDS protocol page for more details ISO14229 - UDS Protocol.
Refer to the DoCAN protocol page for more details ISO15765 - DoCAN Protocol.