Based on the ToLHnet protocol, the new DALI wireless gateway enables remote control of DALI lamps and installations without the need of running long DALI cables. The gateway is attached to a ToLHnet node and integrates a current-limited 16 V DALI bus power supply capable of sourcing up to 50 mA. It can thus be directly connected to one or more lamps without extra gear. The integrated power supply can be disabled by software commands if the gateway is used to drive larger DALI installations equipped with their own bus supplies. Both the ToLHnet node and the gateway can be power by a single 5 V supply.
The communication between the gateways and control units leverages the flexibility of the ToLHnet protocol. The current implementation employs an ISM-band 433 MHz radio link as the primary communication channel between the nodes, optionally an RS-485 transceiver can be installed for situations where faster, more secure and dependable connections are required. Being a fully routed network protocol, there are essentially no limits on the size of the network, as either wireless or wired nodes can act as signal repeaters. Even mixed media networks can be deployed, and special topologies like linear routing (suitable e.g. for street lighting) are explicitly supported and optimized.
The system can handle up to 61440 nodes and is controlled by a master node, usually an SBC like a Raspberry Pi, which can also act as a gateway to the Internet and be operated by PCs, tablets, smartphones, etc...
DALI messages are exchanged by contacting the master node over a TCP connection and encapsulating the requests in a simple textual protocol. These messages are then forwarded through the ToLHnet network to the appropriate DALI gateway that handles all the details and timing requirements of the DALI protocol, and replies with the appropriate answers. The specifications of the communication protocols are fully open, with reference implementations available for customization.
Integrated DALI bus power supply:
- input : 4.75 V ÷ 5.25 V, 280 mA (can be powered by USB)
- output: 16 V, 50 mA
- galvanic isolation: 5.2 kV
- DALI bus loading: 1.8 mA
- galvanic isolation: 4 kV
- Center frequency: 434 MHz
- Data rate: 10 kb/s
- SET: send message to DALI bus, without waiting for reply
payload: DALI forward frame
- GET: send message and wait for reply
payload: DALI forward frame
reply: DALI backward frame (empty if no answer received, error if collision detected)
- MSG: notification of transaction on the DALI bus
payload: <msg_len> <forward_frame> <backward_frame>
- status and control:
- DALI TX enable
- DALI RX enable (MSG o on DALI_DATA)
- DALI bus power supply enable
- DALI error notifications enable (MSG on DALI_SC)
- DALI bus status (normal, undervoltage, overvoltage, overcurrent)
- DALI transceiver failure
- DALI bus power supply failure
- DALI gateway: 5 cm × 4 cm × 2.5 cm (bare board, no enclosure)
- ToLHnet node: 7 cm × 5 cm × 2.5 cm (reference design, to be customized)