02_Nodes.md

Policumbent CAN Bus Documentation - Nodes and messages

List of nodes

• Camilla (Gearbox Control Unit)
• Greta (Cerberus' gearbox receiver)
• Raspberry Pi
• DumBMS (Battery Control Unit)
• whereami

Gearbox

The gearbox has two types of messages:

• RefusoData
• GbError
• GbData

We divide them due to ID priority, giving GbError higher priority since the gearbox is the most critical ECU of our bikes. RefusoData has the highest priority since it has to be used by the gearbox to compute the real time position.

RefusoData

• RefusoData encodes the voltage got by the potentiometer mounted on the feedback board, representing the position of the gearbox cassette.
• ID: 0x24
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
Position	0	16	0.01	0	0	10	V	Voltage representing position

GbError

• GbError encodes the error diagnostics message type for the gearbox
• ID: 0x222
• DLC: 1

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
GbErrCode	0	3	1	0	0	7	-	Gearbox error code
GbGear	3	5	1	0	0	16	-	Current gear

GbData

• GbData encodes the error diagnostics message type for the gearbox
• ID: 0x422
• DLC: 1

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
GbGear	0	5	1	0	0	16	-	Current gear

Greta

• GretaError
• GretaData

Greta has two types of messages. Recall that it is present only on Cerberus.

GretaError

• GretaError encodes the error message type for the gearbox receiver
• ID: 0x221
• DLC: 1

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
TimeOutError	0	1	1	0	0	1	-	1 if a receiver timeout has occurred

GretaData

• GretaData encodes the data message type for the gearbox receiver
• ID: 0x421
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
TelekBattery	0	7	1	0	0	100	%	Battery percentage of Telekhambion
RxShifting	7	2	1	0	0	3	-	Shifting information received from Telekhambion

Raspberry Pi

The Raspberry Pi has five types of messages:

• BobSrmPower
• BobSrmCadence
• BobHsSpeed
• BobHsDisplacement
• BobHR

BobSrmPower

• BobSrmPower encodes the power computed by the on-board SRM Power Meter
• ID: 0x441
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
SrmPower	0	16	0.1	0	0	1000	W	Power read by SRM Power Meter

BobSrmCadence

• BobSrmCadence encodes the pedals cadence computed by the on-board SRM Power Meter
• ID: 0x442
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
SrmCadence	16	16	0.1	0	0	1000	rpm	Cadence read by SRM Power Meter

BobHsSpeed

• BobSRM encodes the data collected by the on-board velocity Hall Sensor
• ID: 0x443
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
HsSpeed	0	16	0.01	0	0	200	km/h	Speed computed by Hall Sensor

BobHsDisplacement

• BobHsDisplacement encodes the pedals cadence computed by the on-board SRM Power Meter
• ID: 0x444
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
HsDistance	16	16	1	0	0	9000	m	Distance computed by Hall Sensor

BobHR

• BobSRM encodes the data collected by the on-board velocity Hall Sensor
• ID: 0x446
• DLC: 1

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
HeartRate	0	8	1	0	0	250	bpm	Heart rate received by Bob

DumBMS (1 and 2)

There could be two DumBMS Control Units on the bike (especially on Cerberus) and they have the same messages encoding (N stands for the Control Unit number):

• DumbmsNError
• DumbmsNData

DumbmsNError

• DumbmsNError encodes the batteries undervoltage detection (if any)
• ID 1: 0x280
• ID 2: 0x2A0
• DLC: 1

It encodes the following signal

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
Bat0UnderVolt	0	1	1	0	0	1	-	DumBMS LiPo undervoltage detected
Bat1UnderVolt	1	1	1	0	0	1	-	3S slot 1 undervoltage detected
Bat2UnderVolt	1	1	1	0	0	1	-	3S slot 2 undervoltage detected
Bat3UnderVolt	1	1	1	0	0	1	-	3S slot 3 undervoltage detected
Bat4UnderVolt	1	1	1	0	0	1	-	3S slot 4 undervoltage detected

DumbmsNData

• DumbmsNData encodes the batteries voltages
• ID 1: 0x480
• ID 2: 0x4A0
• DLC: 5

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
Bat0Voltage	0	8	0.1	0	0	1	-	DumBMS LiPo voltage
Bat1Voltage	8	8	0.1	0	0	1	-	3S slot 1 voltage
Bat2Voltage	16	8	0.1	0	0	1	-	3S slot 2 voltage
Bat3Voltage	24	8	0.1	0	0	1	-	3S slot 3 voltage
Bat4Voltage	32	8	0.1	0	0	1	-	3S slot 4 voltage

whereami

whereami has two types of messages:

• whereamiData
• whereamiRawData
• whereamiCoords
• whereamiPosUncert

whereamiData

• whereamiData encodes the data gathered by the GNSS system and linearized with respect to the straight track
• ID: 0x460
• DLC: 4

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
Speed	0	16	0.01	0	0	200	km/h	Parallel speed computed from GNSS data
Distance	16	16	1	0	0	20000	m	Parallel distance computed from GNSS data

whereamiRawData

• whereamiRawData encodes the raw data gathered by the GNSS
• ID: 0x462
• DLC: 4

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
RawSpeed	0	16	0.01	0	0	200	km/h	Raw speed computed from GNSS data
RawDistance	16	16	1	0	0	20000	m	Raw distance computed from GNSS data

whereamiCoords

• whereamiCoords encodes the coordinates given by the GNSS system
• ID: 0x464
• DLC: 8

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
Latitude	0	32	0.000001	0	-90	90	km/h	Latitude given by GNSS
Longitude	32	32	0.000001	0	-180	180	m	Longitude given by GNSS

Notice: both the encoded signals are signed!

whereamiPosUncert

• whereamiPosUncert encodes the position uncertainty computed by the GNSS system
• ID: 0x468
• DLC: 2

It encodes the following signals:

Name	Start	Len	Factor	Offset	Min	Max	Unit	Comment
PosUncertainty	0	16	0.01	0	0	100	m	Position uncertainty computed by GNSS system