Intro¶

With the TDT-Protocol sensors can just send their values on the BUS without complex object catalogue.
An monitor-software is able to display values without knowing anything about the sensors or their configuration.
The CANId of sensors is actually their configurable ID or an global command.

Sensor values are ususally not very important so the CAN-IDs start at 0x200 (max ids 0x800);

Size	Decription	Examples
1	Sub-Id;	Futher index; Sub-Sensor or more specifi kind of thing to be set
1	Reserved	Maybe config-Flags; require Confirmation, is confirmation...
1	Data type	Int, Float, Time, Date, Percent, Promil, Multipacket-String
1	Unit	Hz, °C, Time, Date, PWM, CAN-ID, Name, Description, Room
4	Value	32Bit

Values¶

• Date: year 2B, month 1B, day 1B
• Time: hour 1B, minute 1B, second 1B, subsecond 1B

Device behaviour¶

All devices should shut down after 5 hours when no master-heartbeat is received.

IDs, ranges and commands¶

CAN IDs¶

• 11-Bit-Identifier, (CAN 2.0A); 2048; 0x800
• 29-Bit-Identifier, (CAN 2.0B); 0x20000000

Range	Decription	Examples
0x010-0x0FF	Alarms	Devices have an issue
0x100-0x1FF	Control commands	Set global actuator
0x200-0x2FF	Sensors/actors fixed
0x300-0x6FF	Sensors/actors dynamic
0x6FF-0x7FF	Low priority boradcast	Power on devices

Global actuator¶

Global means that all actuators of an type is addressed and not one concrete partipiant.
An specific partipiant can be specified when sending the target CAN-Id in the value.
In this way the message is still high priority other than the "Remote Transmission Request"

ID	global actuator	Decription
0x100	System command	Perform system command; e.g. reboot, poweroff
0x101	Date/Time	Set date/time of all actuator
0x102	Illumination	Set brightness of lamps
0x103	Powerswitch	Power on devices
0x104	Plant watering pump	Automatically watering indoor plants

System commands¶

Sub-ID	Type
0x0	Shutdown
0x1	Heartbeat

Illumination commands¶

Sub-ID	Type
0x0	Set ambient light
0x1	Get ambient light
0x2	Set ambient light, fading
0x3	Get ambient light, fading
0x4	Set plant light
0x5	Get plant light

Powerswitch commands¶

Sub-ID	Type
0x0	Set powerline for multimedia
0x1	Get powerline for multimedia

Multipacket-Strings¶

Address	Type
0x0	Package count
0x1	Package number
0x2..0x3	Data

Actuator introduction¶

When introduction is requested by system command, each device must send description for each subid.

Example¶

Turn on the lights¶

Data	Size	Description
0x100	29 Bits	CAN-Id: Global command
0x0	1 Byte	Message-Type: Global command
0x0	1 Byte	Sub-Id: Set ambient light
0x1	1 Byte	Data-Type: Integer
0x1	1 Byte	PWM: PWM permilli
1000	4 Byte	Value: Full Brightness

Usecases¶

• simple actors can filter message to "Global actuator" messages, at least "system commands"
• There are 14 or 28 Filters on STM32Fs

ID Assigning¶

Some STM32 have an internal 96-bit unique ID.

V2¶

Size	Decription	Examples
1	Packet type	Standard TDT packet
1	Sub-Id;	Futher index; Sub-Sensor or more specifi kind of thing to be set
1	Data type	Int, Float, Time, Date, Percent, Promil, Multipacket-String
1	Unit	Hz, °C, Time, Date, PWM, CAN-ID, Name, Description, Room
4	Value	32Bit

Multimessage package¶

There should be the posssibillity to write the complete SPI-Flash even if it takes forever.
Not every slave needs to be able to send super big blocks. But every slave should be able to
send e.g. descriptions.

Size	Decription	Examples
1	Packet type	Multimessage package
1	count	Number of packages
1	number	0: value=data length in bytes
4	Value	32Bit

Size	Decription	Examples
1	Packet type	Multimessage package 2
1	id	Mailbox
1	number	0: value=data length in bytes
		1: value=number of messages
		2..x: data
4	Value	32Bit

Diagnose¶