Support optional WiFi extension to MB6HC

11 files changed, 144 insertions, 56 deletions

diff --git a/.cproject b/.cproject
index 1280d93a..ec0fce31 100644
--- a/.cproject
+++ b/.cproject
@@ -612,7 +612,7 @@
 						</toolChain>
 					</folderInfo>
 					<sourceEntries>
-						<entry excluding="src/Networking/LwipEthernet/Lwip/src/apps/smtp|src/Networking/LwipEthernet/Lwip/src/apps/snmp|src/Networking/LwipEthernet/Lwip/src/apps/httpd|src/Hardware/SAME5x|/src/Networking/LwipEthernet/Lwip/test|src/DuetNG|src/Networking/LwipEthernet/Lwip/src/apps/tftp|src/Networking/W5500Ethernet|src/Networking/LwipEthernet/Lwip/src/netif/ppp|src/Networking/LwipEthernet/Lwip/src/apps/lwiperf|src/Networking/LwipEthernet/Lwip/src/apps/altcp_tls|src/Networking/LwipEthernet/Lwip/src/apps/sntp|src/Display|src/Networking/LwipEthernet/Lwip/src/apps/http|src/Networking/ESP8266WiFi|src/Duet3Mini|src/Hardware/SAM4E|src/Pccb|/src/Networking/LwipEthernet/Lwip/src/apps/mqtt|src/Hardware/SAM4S|src/DuetM|src/Networking/LwipEthernet/Lwip/doc" flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name=""/>
+						<entry excluding="src/Networking/LwipEthernet/Lwip/src/apps/smtp|src/Networking/LwipEthernet/Lwip/src/apps/snmp|src/Networking/LwipEthernet/Lwip/src/apps/httpd|src/Hardware/SAME5x|/src/Networking/LwipEthernet/Lwip/test|src/DuetNG|src/Networking/LwipEthernet/Lwip/src/apps/tftp|src/Networking/W5500Ethernet|src/Networking/LwipEthernet/Lwip/src/netif/ppp|src/Networking/LwipEthernet/Lwip/src/apps/lwiperf|src/Networking/LwipEthernet/Lwip/src/apps/altcp_tls|src/Networking/LwipEthernet/Lwip/src/apps/sntp|src/Display|src/Networking/LwipEthernet/Lwip/src/apps/http|src/Duet3Mini|src/Hardware/SAM4E|src/Pccb|/src/Networking/LwipEthernet/Lwip/src/apps/mqtt|src/Hardware/SAM4S|src/DuetM|src/Networking/LwipEthernet/Lwip/doc" flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name=""/>
 					</sourceEntries>
 				</configuration>
 			</storageModule>
diff --git a/src/Config/Pins_Duet3_MB6HC.h b/src/Config/Pins_Duet3_MB6HC.h
index 2dab95d8..5705b09d 100644
--- a/src/Config/Pins_Duet3_MB6HC.h
+++ b/src/Config/Pins_Duet3_MB6HC.h
@@ -14,10 +14,12 @@
 #define IAP_CAN_LOADER_FILE		"Duet3_CANiap32_" BOARD_SHORT_NAME ".bin"
 constexpr uint32_t IAP_IMAGE_START = 0x20458000;		// last 32kb of RAM
 
+#define WIFI_FIRMWARE_FILE		"DuetWiFiServer_32S3.bin"
+
 // Features definition
 // Networking support
 #define HAS_LWIP_NETWORKING		1
-#define HAS_WIFI_NETWORKING		0
+#define HAS_WIFI_NETWORKING		1
 
 // Storage support
 #define HAS_SBC_INTERFACE		1
@@ -386,6 +388,28 @@ constexpr Pin APIN_SBC_SPI_SCK = PortCPin(24);
 constexpr Pin APIN_SBC_SPI_SS0 = PortCPin(25);
 constexpr GpioPinFunction SBCPinPeriphMode = GpioPinFunction::C;
 
+// WiFi pins, mostly shared with the SBC interface
+#define ESP_SPI					SPI1
+#define ESP_SPI_INTERFACE_ID	ID_SPI1
+#define ESP_SPI_IRQn			SPI1_IRQn
+#define ESP_SPI_HANDLER			SPI1_Handler
+
+constexpr Pin APIN_ESP_SPI_MOSI = PortCPin(27);
+constexpr Pin APIN_ESP_SPI_MISO = PortCPin(26);
+constexpr Pin APIN_ESP_SPI_SCK  = PortCPin(24);
+constexpr Pin APIN_ESP_SPI_SS0  = PortCPin(25);
+constexpr GpioPinFunction SPIPeriphMode = GpioPinFunction::C;
+
+constexpr Pin APIN_SerialWiFi_TXD = PortDPin(19);
+constexpr Pin APIN_SerialWiFi_RXD = PortDPin(18);
+constexpr GpioPinFunction SerialWiFiPeriphMode = GpioPinFunction::C;
+
+constexpr Pin EspResetPin = PortCPin(14);			// Low on this in holds the WiFi module in reset (ESP_RESET)
+constexpr Pin EspEnablePin = NoPin;					// High to enable the WiFi module, low to power it down (ESP_CH_PD)
+constexpr Pin EspDataReadyPin = PortAPin(2);		// Input from the WiFi module indicating that it wants to transfer data (ESP GPIO0)
+constexpr Pin SamTfrReadyPin = PortEPin(2);			// Output from the SAM to the WiFi module indicating we can accept a data transfer (ESP GPIO4 via 7474)
+constexpr Pin SamCsPin = PortCPin(25);				// SPI NPCS pin, input from WiFi module
+
 // CAN
 constexpr Pin APIN_CAN0_RX = PortBPin(3);
 constexpr Pin APIN_CAN0_TX = PortBPin(2);
@@ -417,8 +441,8 @@ constexpr Pin SbcTfrReadyPin = PortEPin(2);
 
 // DMA channel allocation
 constexpr DmaChannel DmacChanHsmci = 0;			// this is hard coded in the ASF HSMCI driver
-//constexpr DmaChannel DmacChanWiFiTx = 1;		// only on v0.3 board
-//constexpr DmaChannel DmacChanWiFiRx = 2;		// only on v0.3 board
+constexpr DmaChannel DmacChanWiFiTx = 1;
+constexpr DmaChannel DmacChanWiFiRx = 2;
 constexpr DmaChannel DmacChanTmcTx = 3;
 constexpr DmaChannel DmacChanTmcRx = 4;
 constexpr DmaChannel DmacChanSbcTx = 5;
diff --git a/src/Config/Pins_DuetNG.h b/src/Config/Pins_DuetNG.h
index 09e53fe6..e9c507dd 100644
--- a/src/Config/Pins_DuetNG.h
+++ b/src/Config/Pins_DuetNG.h
@@ -139,7 +139,6 @@ constexpr size_t MaxSpindles = 4;					// Maximum number of configurable spindles
 constexpr size_t NumSerialChannels = 2;				// The number of serial IO channels not counting the WiFi serial connection (USB and one auxiliary UART)
 #define SERIAL_MAIN_DEVICE	SerialUSB
 #define SERIAL_AUX_DEVICE	Serial
-#define SERIAL_WIFI_DEVICE	Serial1
 
 constexpr Pin UsbVBusPin = PortCPin(22);			// Pin used to monitor VBUS on USB port
 
@@ -483,9 +482,9 @@ constexpr Pin APIN_Serial0_TXD = PortAPin(10);
 constexpr GpioPinFunction Serial0PeriphMode = GpioPinFunction::A;
 
 // Serial1
-constexpr Pin APIN_Serial1_RXD = PortAPin(5);
-constexpr Pin APIN_Serial1_TXD = PortAPin(6);
-constexpr GpioPinFunction Serial1PeriphMode = GpioPinFunction::C;
+constexpr Pin APIN_SerialWiFi_RXD = PortAPin(5);
+constexpr Pin APIN_SerialWiFi_TXD = PortAPin(6);
+constexpr GpioPinFunction SerialWiFiPeriphMode = GpioPinFunction::C;
 
 // Duet pin numbers to control the WiFi interface on the Duet WiFi
 #define ESP_SPI					SPI
diff --git a/src/Hardware/SAM4E/Devices.cpp b/src/Hardware/SAM4E/Devices.cpp
index c5a5fcae..2dbbfc08 100644
--- a/src/Hardware/SAM4E/Devices.cpp
+++ b/src/Hardware/SAM4E/Devices.cpp
@@ -11,8 +11,8 @@
 #include <AnalogOut.h>
 #include <pmc/pmc.h>
 
-AsyncSerial Serial (UART0, UART0_IRQn, ID_UART0, 512, 512, 	[](AsyncSerial*) noexcept { }, [](AsyncSerial*) noexcept { });
-AsyncSerial Serial1(UART1, UART1_IRQn, ID_UART1, 512, 512,	[](AsyncSerial*) noexcept { }, [](AsyncSerial*) noexcept { });
+AsyncSerial Serial(UART0, UART0_IRQn, ID_UART0, 512, 512, 	[](AsyncSerial*) noexcept { }, [](AsyncSerial*) noexcept { });
+AsyncSerial SerialWiFi(UART1, UART1_IRQn, ID_UART1, 512, 512,	[](AsyncSerial*) noexcept { }, [](AsyncSerial*) noexcept { });
 SerialCDC SerialUSB;
 
 void UART0_Handler(void) noexcept
@@ -22,7 +22,7 @@ void UART0_Handler(void) noexcept
 
 void UART1_Handler(void) noexcept
 {
-	Serial1.IrqHandler();
+	SerialWiFi.IrqHandler();
 }
 
 void SerialInit() noexcept
@@ -31,9 +31,9 @@ void SerialInit() noexcept
 	SetPinFunction(APIN_Serial0_TXD, Serial0PeriphMode);
 	EnablePullup(APIN_Serial0_RXD);
 
-	SetPinFunction(APIN_Serial1_RXD, Serial1PeriphMode);
-	SetPinFunction(APIN_Serial1_TXD, Serial1PeriphMode);
-	EnablePullup(APIN_Serial1_RXD);
+	SetPinFunction(APIN_SerialWiFi_RXD, SerialWiFiPeriphMode);
+	SetPinFunction(APIN_SerialWiFi_TXD, SerialWiFiPeriphMode);
+	EnablePullup(APIN_SerialWiFi_RXD);
 }
 
 void SdhcInit() noexcept
diff --git a/src/Hardware/SAM4E/Devices.h b/src/Hardware/SAM4E/Devices.h
index dbac6b94..df072e76 100644
--- a/src/Hardware/SAM4E/Devices.h
+++ b/src/Hardware/SAM4E/Devices.h
@@ -11,7 +11,7 @@
 #include <AsyncSerial.h>
 
 extern AsyncSerial Serial;
-extern AsyncSerial Serial1;
+extern AsyncSerial SerialWiFi;
 
 #define SUPPORT_USB		1		// needed by SerialCDC.h
 #include <SerialCDC.h>
diff --git a/src/Hardware/SAME70/Devices.cpp b/src/Hardware/SAME70/Devices.cpp
index 2af3ed6a..1e47f4a5 100644
--- a/src/Hardware/SAME70/Devices.cpp
+++ b/src/Hardware/SAME70/Devices.cpp
@@ -37,6 +37,21 @@ USARTClass Serial1(USART2, USART2_IRQn, ID_USART2, 512, 512,
 					}
 				);
 
+#if defined(DUET3_MB6HC)
+AsyncSerial SerialWiFi(UART4, UART4_IRQn, ID_UART4, 512, 512,
+					[](AsyncSerial*) noexcept
+					{
+						SetPinFunction(APIN_SerialWiFi_RXD, SerialWiFiPeriphMode);
+						SetPinFunction(APIN_SerialWiFi_TXD, SerialWiFiPeriphMode);
+					},
+					[](AsyncSerial*) noexcept
+					{
+						ClearPinFunction(APIN_SerialWiFi_RXD);
+						ClearPinFunction(APIN_SerialWiFi_TXD);
+					}
+				);
+#endif
+
 SerialCDC SerialUSB;
 
 void UART2_Handler(void) noexcept
@@ -49,6 +64,13 @@ void USART2_Handler(void) noexcept
 	Serial1.IrqHandler();
 }
 
+#if defined(DUET3_MB6HC)
+void UART4_Handler(void) noexcept
+{
+	SerialWiFi.IrqHandler();
+}
+#endif
+
 void SdhcInit() noexcept
 {
 	SetPinFunction(HsmciMclkPin, HsmciMclkPinFunction);
diff --git a/src/Hardware/SAME70/Devices.h b/src/Hardware/SAME70/Devices.h
index 22e03e47..87b5de23 100644
--- a/src/Hardware/SAME70/Devices.h
+++ b/src/Hardware/SAME70/Devices.h
@@ -14,6 +14,10 @@
 extern AsyncSerial Serial;
 extern USARTClass Serial1;
 
+#if defined(DUET3_MB6HC)
+extern AsyncSerial SerialWiFi;
+#endif
+
 #define SUPPORT_USB		1		// needed by SerialCDC.h
 #include "SerialCDC.h"
 
diff --git a/src/Networking/ESP8266WiFi/WiFiInterface.cpp b/src/Networking/ESP8266WiFi/WiFiInterface.cpp
index 9e08438b..07ea4e6b 100644
--- a/src/Networking/ESP8266WiFi/WiFiInterface.cpp
+++ b/src/Networking/ESP8266WiFi/WiFiInterface.cpp
@@ -36,7 +36,10 @@ static_assert(SsidLength == SsidBufferLength, "SSID lengths in NetworkDefs.h and
 # define USE_DMAC_MANAGER	0		// use SAMD/SAME DMA controller via DmacManager module
 # define USE_XDMAC			0		// use SAME7 XDMA controller
 
-#elif defined(DUET3_V03) || defined(SAME70XPLD)
+#elif defined(DUET3_MB6HC)
+
+# include <pmc/pmc.h>
+# include <spi/spi.h>
 
 # define USE_PDC			0		// use SAM4 peripheral DMA controller
 # define USE_DMAC			0		// use SAM4 general DMA controller
@@ -186,6 +189,10 @@ void SERIAL_WIFI_ISR3() noexcept
 	SerialWiFiDevice->Interrupt3();
 }
 
+#else
+
+#define SERIAL_WIFI_DEVICE	(SerialWiFi)
+
 #endif
 
 static volatile bool transferPending = false;
@@ -2042,8 +2049,8 @@ void WiFiInterface::StartWiFi() noexcept
 #endif
 
 #if !SAME5x && !defined(__LPC17xx__)
-	SetPinFunction(APIN_Serial1_TXD, Serial1PeriphMode);				// connect the pins to the UART
-	SetPinFunction(APIN_Serial1_RXD, Serial1PeriphMode);				// connect the pins to the UART
+	SetPinFunction(APIN_SerialWiFi_TXD, SerialWiFiPeriphMode);		// connect the pins to the UART
+	SetPinFunction(APIN_SerialWiFi_RXD, SerialWiFiPeriphMode);		// connect the pins to the UART
 #endif
 	SERIAL_WIFI_DEVICE.begin(WiFiBaudRate);						// initialise the UART, to receive debug info
 	debugMessageChars = 0;
@@ -2061,8 +2068,8 @@ void WiFiInterface::ResetWiFi() noexcept
 #endif
 
 #if !defined(SAME5x)
-	pinMode(APIN_Serial1_TXD, INPUT_PULLUP);					// just enable pullups on TxD and RxD pins
-	pinMode(APIN_Serial1_RXD, INPUT_PULLUP);
+	pinMode(APIN_SerialWiFi_TXD, INPUT_PULLUP);					// just enable pullups on TxD and RxD pins
+	pinMode(APIN_SerialWiFi_RXD, INPUT_PULLUP);
 #endif
 	currentMode = WiFiState::disabled;
 
@@ -2113,15 +2120,15 @@ void WiFiInterface::ResetWiFiForUpload(bool external) noexcept
 	if (external)
 	{
 #if !defined(DUET3MINI)
-		pinMode(APIN_Serial1_TXD, INPUT_PULLUP);					// just enable pullups on TxD and RxD pins
-		pinMode(APIN_Serial1_RXD, INPUT_PULLUP);
+		pinMode(APIN_SerialWiFi_TXD, INPUT_PULLUP);					// just enable pullups on TxD and RxD pins
+		pinMode(APIN_SerialWiFi_RXD, INPUT_PULLUP);
 #endif
 	}
 	else
 	{
 #if !SAME5x && !defined(__LPC17xx__)
-		SetPinFunction(APIN_Serial1_TXD, Serial1PeriphMode);				// connect the pins to the UART
-		SetPinFunction(APIN_Serial1_RXD, Serial1PeriphMode);				// connect the pins to the UART
+		SetPinFunction(APIN_SerialWiFi_TXD, SerialWiFiPeriphMode);	// connect the pins to the UART
+		SetPinFunction(APIN_SerialWiFi_RXD, SerialWiFiPeriphMode);	// connect the pins to the UART
 #endif
 	}
 
diff --git a/src/Networking/Network.cpp b/src/Networking/Network.cpp
index 376b90f6..91193ca5 100644
--- a/src/Networking/Network.cpp
+++ b/src/Networking/Network.cpp
@@ -86,23 +86,17 @@ Network::Network(Platform& p) noexcept : platform(p)
 #endif
 {
 #if HAS_NETWORKING
-#if defined(DUET3_MB6HC) || defined(DUET3_MB6XD)
+# if defined(DUET3_MB6HC) || defined(DUET3_MB6XD)
 	interfaces[0] = new LwipEthernetInterface(p);
-#elif defined(DUET_NG) || defined(DUET3MINI_V04)
+# elif defined(DUET_NG) || defined(DUET3MINI_V04)
 	interfaces[0] = nullptr;			// we set this up in Init()
-#elif defined(FMDC_V02) || defined(FMDC_V03)
+# elif defined(FMDC_V02) || defined(FMDC_V03)
 	interfaces[0] = new WiFiInterface(p);
-#elif defined(DUET_M)
+# elif defined(DUET_M)
 	interfaces[0] = new W5500Interface(p);
-#elif defined(__LPC17xx__)
-# if HAS_WIFI_NETWORKING
-	interfaces[0] = new WiFiInterface(p);
- #else
-	interfaces[0] = new RTOSPlusTCPEthernetInterface(p);
- #endif
-#else
-# error Unknown board
-#endif
+# else
+#  error Unknown board
+# endif
 #endif // HAS_NETWORKING
 }
 
@@ -113,8 +107,10 @@ Network::Network(Platform& p) noexcept : platform(p)
 
 constexpr ObjectModelArrayDescriptor Network::interfacesArrayDescriptor =
 {
-	nullptr,
-	[] (const ObjectModel *self, const ObjectExplorationContext& context) noexcept -> size_t { return NumNetworkInterfaces; },
+	// 0. Interfaces
+	{
+		nullptr,
+		[] (const ObjectModel *self, const ObjectExplorationContext& context) noexcept -> size_t { return ((Network*)self)->GetNumNetworkInterfaces(); },
 #if HAS_NETWORKING
 	[] (const ObjectModel *self, ObjectExplorationContext& context) noexcept -> ExpressionValue { return ExpressionValue(((Network*)self)->interfaces[context.GetIndex(0)]); }
 #endif
@@ -200,10 +196,24 @@ void Network::Init() noexcept
 	slowLoop = 0;
 }
 
+#if defined(DUET3_MB6HC)
+
+// Create the additional interface. Called after we have established that we are not running in SBC mode but before config.g is run.
+void Network::CreateAdditionalInterface() noexcept
+{
+	if (platform.GetBoardType() >= BoardType::Duet3_6HC_v102)
+	{
+		interfaces[1] = new WiFiInterface(platform);
+		numActualNetworkInterfaces = 2;
+	}
+}
+
+#endif
+
 GCodeResult Network::EnableProtocol(unsigned int interface, NetworkProtocol protocol, int port, int secure, const StringRef& reply) noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		return interfaces[interface]->EnableProtocol(protocol, port, secure, reply);
 	}
@@ -219,7 +229,7 @@ GCodeResult Network::EnableProtocol(unsigned int interface, NetworkProtocol prot
 GCodeResult Network::DisableProtocol(unsigned int interface, NetworkProtocol protocol, const StringRef& reply) noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		NetworkInterface * const iface = interfaces[interface];
 		const GCodeResult ret = iface->DisableProtocol(protocol, reply);
@@ -280,7 +290,7 @@ GCodeResult Network::DisableProtocol(unsigned int interface, NetworkProtocol pro
 GCodeResult Network::ReportProtocols(unsigned int interface, const StringRef& reply) const noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		return interfaces[interface]->ReportProtocols(reply);
 	}
@@ -296,7 +306,7 @@ GCodeResult Network::ReportProtocols(unsigned int interface, const StringRef& re
 GCodeResult Network::EnableInterface(unsigned int interface, int mode, const StringRef& ssid, const StringRef& reply) noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		NetworkInterface * const iface = interfaces[interface];
 		const GCodeResult ret = iface->EnableInterface(mode, ssid, reply);
@@ -485,7 +495,7 @@ void Network::Exit() noexcept
 GCodeResult Network::GetNetworkState(unsigned int interface, const StringRef& reply) noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		return interfaces[interface]->GetNetworkState(reply);
 	}
@@ -501,7 +511,7 @@ GCodeResult Network::GetNetworkState(unsigned int interface, const StringRef& re
 bool Network::IsWiFiInterface(unsigned int interface) const noexcept
 {
 #if HAS_NETWORKING
-	return interface < NumNetworkInterfaces && interfaces[interface]->IsWiFiInterface();
+	return interface < GetNumNetworkInterfaces() && interfaces[interface]->IsWiFiInterface();
 #else
 	return false;
 #endif
@@ -601,7 +611,7 @@ void Network::Diagnostics(MessageType mtype) noexcept
 int Network::EnableState(unsigned int interface) const noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		return interfaces[interface]->EnableState();
 	}
@@ -626,7 +636,7 @@ IPAddress Network::GetIPAddress(unsigned int interface) const noexcept
 {
 	return
 #if HAS_NETWORKING
-			(interface < NumNetworkInterfaces) ? interfaces[interface]->GetIPAddress() :
+			(interface < GetNumNetworkInterfaces()) ? interfaces[interface]->GetIPAddress() :
 #endif
 					IPAddress();
 }
@@ -635,7 +645,7 @@ IPAddress Network::GetNetmask(unsigned int interface) const noexcept
 {
 	return
 #if HAS_NETWORKING
-			(interface < NumNetworkInterfaces) ? interfaces[interface]->GetNetmask() :
+			(interface < GetNumNetworkInterfaces()) ? interfaces[interface]->GetNetmask() :
 #endif
 					IPAddress();
 }
@@ -644,7 +654,7 @@ IPAddress Network::GetGateway(unsigned int interface) const noexcept
 {
 	return
 #if HAS_NETWORKING
-			(interface < NumNetworkInterfaces) ? interfaces[interface]->GetGateway() :
+			(interface < GetNumNetworkInterfaces()) ? interfaces[interface]->GetGateway() :
 #endif
 					IPAddress();
 }
@@ -652,7 +662,7 @@ IPAddress Network::GetGateway(unsigned int interface) const noexcept
 bool Network::UsingDhcp(unsigned int interface) const noexcept
 {
 #if HAS_NETWORKING
-	return interface < NumNetworkInterfaces && interfaces[interface]->UsingDhcp();
+	return interface < GetNumNetworkInterfaces() && interfaces[interface]->UsingDhcp();
 #else
 	return false;
 #endif
@@ -696,7 +706,7 @@ void Network::SetHostname(const char *name) noexcept
 GCodeResult Network::SetMacAddress(unsigned int interface, const MacAddress& mac, const StringRef& reply) noexcept
 {
 #if HAS_NETWORKING
-	if (interface < NumNetworkInterfaces)
+	if (interface < GetNumNetworkInterfaces())
 	{
 		return interfaces[interface]->SetMacAddress(mac, reply);
 	}
@@ -711,7 +721,7 @@ GCodeResult Network::SetMacAddress(unsigned int interface, const MacAddress& mac
 const MacAddress& Network::GetMacAddress(unsigned int interface) const noexcept
 {
 #if HAS_NETWORKING
-	if (interface >= NumNetworkInterfaces)
+	if (interface >= GetNumNetworkInterfaces())
 	{
 		interface = 0;
 	}
diff --git a/src/Networking/Network.h b/src/Networking/Network.h
index 2543443d..eef40cd5 100644
--- a/src/Networking/Network.h
+++ b/src/Networking/Network.h
@@ -14,10 +14,10 @@
 #include <ObjectModel/ObjectModel.h>
 #include <General/NamedEnum.h>
 
-#if defined(DUET3_V03)
-const size_t NumNetworkInterfaces = 2;
+#if defined(DUET3_MB6HC) && HAS_WIFI_NETWORKING
+const size_t MaxNetworkInterfaces = 2;
 #elif defined(DUET3_MB6HC) || defined(DUET3_MB6XD) || defined(DUET_NG) || defined(DUET_M) || defined(__LPC17xx__) || defined(PCCB) || defined(DUET3MINI)
-const size_t NumNetworkInterfaces = 1;
+const size_t MaxNetworkInterfaces = 1;
 #else
 # error Wrong Network.h file included
 #endif
@@ -78,6 +78,10 @@ public:
 	void Diagnostics(MessageType mtype) noexcept;
 	bool IsWiFiInterface(unsigned int interface) const noexcept;
 
+#if defined(DUET3_MB6HC)
+	void CreateAdditionalInterface() noexcept;
+#endif
+
 	GCodeResult EnableInterface(unsigned int interface, int mode, const StringRef& ssid, const StringRef& reply) noexcept;
 	GCodeResult EnableProtocol(unsigned int interface, NetworkProtocol protocol, int port, int secure, const StringRef& reply) noexcept;
 	GCodeResult DisableProtocol(unsigned int interface, NetworkProtocol protocol, const StringRef& reply) noexcept;
@@ -121,12 +125,13 @@ protected:
 	OBJECT_MODEL_ARRAY(interfaces)
 
 private:
+	unsigned int GetNumNetworkInterfaces() const noexcept;
 	WiFiInterface *FindWiFiInterface() const noexcept;
 
 	Platform& platform;
 
 #if HAS_NETWORKING
-	NetworkInterface *interfaces[NumNetworkInterfaces];
+	NetworkInterface *interfaces[MaxNetworkInterfaces];
 #endif
 
 #if HAS_RESPONDERS
@@ -146,7 +151,21 @@ private:
 #if SUPPORT_HTTP
 	String<StringLength20> corsSite;
 #endif
+
+#ifdef DUET3_MB6HC
+	unsigned int numActualNetworkInterfaces = 1;	// don't add a second interface until we know whether the board supports it
+#endif
+
 	char hostname[16];								// Limit DHCP hostname to 15 characters + terminating 0
 };
 
+inline unsigned int Network::GetNumNetworkInterfaces() const noexcept
+{
+#if defined(DUET3_MB6HC)
+	return numActualNetworkInterfaces;
+#else
+	return MaxNetworkInterfaces;
+#endif
+}
+
 #endif /* SRC_NETWORK_NETWORK_H_ */
diff --git a/src/Platform/RepRap.cpp b/src/Platform/RepRap.cpp
index cf3d9cbb..0353012c 100644
--- a/src/Platform/RepRap.cpp
+++ b/src/Platform/RepRap.cpp
@@ -607,6 +607,9 @@ void RepRap::Init() noexcept
 
 		if (rslt == GCodeResult::ok)
 		{
+# if defined(DUET3_MB6HC)
+			network->CreateAdditionalInterface();		// do this now because config.g may refer to it
+# endif
 			// Run the configuration file
 			if (!RunStartupFile(GCodes::CONFIG_FILE) && !RunStartupFile(GCodes::CONFIG_BACKUP_FILE))
 			{