Layer: Foundation · Build flags: PC_ENABLE_ZIGBEE, PC_ENABLE_GATEWAY

What this example teaches

A Zigbee network plugged into the gateway through a Silicon Labs EmberZNet network co-processor (NCP), which speaks EZSP over the ASH data-link protocol on a UART. This resets the NCP and decodes its ASH frames; a DATA frame carrying an EZSP callback (an incoming Zigbee message) is bridged northbound.

Zigbee NCP --UART--> pc_ash_frame_decode() --> EZSP payload -> pc_gateway_uplink()
                                                                 |
                                          envelope + topic  zigbee/0/<node>
                                                                 |
                                                  northbound publish (MQTT/HTTP/WS)

ASH wraps each frame as [control | payload | CRC16], byte-stuffs the reserved control bytes, and terminates with a Flag 0x7E. services/zigbee does the framing:

uint8_t control, payload[128]; uint16_t plen;
int n = pc_ash_frame_decode(buf, len, &control, payload, sizeof(payload), &plen);
if (n > 0 && (control & 0x80) == 0 /* HislipMsg::DATA frame */)
    pc_gateway_uplink(0, node, payload, plen, 0);

pc_ash_frame_encode() builds a frame the same way (this sketch sends an ASH RST at boot). The CRC is CRC-16/CCITT; the codec is host-tested against the documented RST frame (C0 38 BC 7E) and the byte-stuffing in test/test_zigbee.

Interpreting the EZSP command inside a DATA frame - version negotiation, the ACK/sequence numbers, the incomingMessageHandler fields - is application work; this sketch bridges the raw EZSP payload to show the transport path.

Wiring (ESP32 <-> Zigbee NCP)

NCP	ESP32
TX	GPIO 16 (RX)
RX	GPIO 17 (TX)
VCC	3V3
GND	GND

115200 8N1 (an EFR32 / EM357 NCP; RTS/CTS optional).

Build-flag note

The flags must reach the library build, so pass them as build flags:

pio ci --board=esp32dev --project-option="framework=arduino" \
  --project-option="build_flags=-DPC_ENABLE_ZIGBEE=1 -DPC_ENABLE_GATEWAY=1" \
  --lib="." examples/Drivers/ZigbeeGateway/ZigbeeGateway.ino