CAN/Cyphal

Cyphal defines the communication stack from physical layer via transport and presentation up to the application layer.

The software implementation is included in the Cyphal Library.

Periodically data exchange is done with a subscriber / publisher structure between the platforms of the Highdra.

Additionally a register interface offers configuration of the Cyphal nodes. Available registers are listed for each board's firmware in addition to the default registers:

• Default Registers
• BMS Register
• MB Register
• MMB Register

External Links

• The official Cyphal Specification
• Cyphal data struct definitions: public_regulated_data_types
• Cyphal message to C converter: nunavut
• C-Library for Cyphal: libcanard

CAN Communication Limitations

• Minimum of two devices (e.g. one device under test / BMS and one receiving monitor / PC)
  • If only one participant is present, the CAN controller will perform automatic message repeats (not getting acknowledged)
• CAN bus requires power supply / bus voltage
  • e.g. by activating the BMS latches or HS, alternatively by apply of 5V to the CAN VDD

Reserved Cyphal Subject Port

Subject Port	Description
[7168, 8191]	Reserved by Cyphal (as for Services: [384, 511])
6060	BMS Power Data Publish, starcopter.highdra.bms.PowerData.0.2
6061	BMS Temperature Data Publish, starcopter.highdra.bms.TempData.0.1
6062	BMS State Data Publish, starcopter.highdra.bms.State.0.2
6063	BMS Energy Source Publish, reg.udral.physics.electricity.Power.0.1
6064	BMS Data Publish, starcopter.highdra.bms.BMSData.0.1
---	---
xxxx	MB Sync pulse (for MMB Synchronization)
xxxx	MB Data
xxxx	MMB Data

Note

Maybe change all internal ports to [6144,7167] - Non-standard fixed regulated identifiers (i.e., vendor-specific).

Reserved Cyphal Node IDs

Node ID	Module Reservation
0	MB
1, 3, 5, 7, 9, 11	MMB (at corresponding slot position)
2, 4, 6, 8, 10, 12	BMS (at corresponding slot position)
13	Gear Controller