Add PoE support for the RAK10720 (RAK4631 + RAK13800 + RAK19018) 🤖🤖

examples/simple_repeater/main.cpp

@@ -37,7 +37,14 @@ static unsigned long userBtnDownAt = 0;
 
 void setup() {
   Serial.begin(115200);
+#ifdef WITH_W5100S_POE
+  // PoE cold-start: get to board.begin() (which activates the W5100S load)
+  // ASAP, before the RAK19018/Silvertel converter folds back. Skip the 1 s
+  // serial-settle delay — there is no operator on the serial port on PoE.
+  delay(20);
+#else
   delay(1000);
+#endif
 
   board.begin();
 
@@ -205,6 +212,12 @@ void loop() {
 #ifdef HAS_EXTERNAL_WATCHDOG
   external_watchdog.loop();
 #endif
+
+#ifdef WITH_W5100S_POE
+  // PoE-powered (RAK19018/Silvertel): the device must NEVER sleep. CPU sleep
+  // drops the current draw below the converter's ~125 mA hold threshold,
+  // making it fold back and reset. Skip the powersaving/sleep path entirely.
+#else
   if (the_mesh.getNodePrefs()->powersaving_enabled && !the_mesh.hasPendingWork()) {
 #if defined(NRF52_PLATFORM)
     board.sleep(0); // nrf ignores seconds param, sleeps whenever possible
@@ -214,4 +227,5 @@ void loop() {
     }
 #endif
   }
+#endif // WITH_W5100S_POE
 }

examples/simple_room_server/main.cpp

@@ -28,7 +28,14 @@ static char ethernet_command[MAX_POST_TEXT_LEN+1];
 
 void setup() {
   Serial.begin(115200);
+#ifdef WITH_W5100S_POE
+  // PoE cold-start: get to board.begin() (which activates the W5100S load)
+  // ASAP, before the RAK19018/Silvertel converter folds back. Skip the 1 s
+  // serial-settle delay — there is no operator on the serial port on PoE.
+  delay(20);
+#else
   delay(1000);
+#endif
 
   board.begin();
 

src/helpers/ethernet/RAK13800/RAK13800EthernetInterface.cpp

@@ -13,7 +13,37 @@ SPIClass ETHERNET_SPI_PORT(NRF_SPIM1, PIN_SPI1_MISO, PIN_SPI1_SCK, PIN_SPI1_MOSI
 #define PIN_ETHERNET_RESET 21
 #define PIN_ETHERNET_SS 26
 
+#ifdef WITH_W5100S_POE
+  // Give the RAK19018 (Silvertel) PoE converter time to latch on the current the
+  // W5100S is already drawing (see variants/rak4631/W5100SPoE.cpp) before doing the
+  // disruptive Ethernet-library bring-up (PHY soft-reset + blocking DHCP), which
+  // otherwise collapses the marginal PoE supply at cold start.
+  #ifndef ETH_POE_DEFER_MS
+    #define ETH_POE_DEFER_MS 6000
+  #endif
+  // Static fallback if no DHCP server answers (override per network).
+  #ifndef ETH_STATIC_IP
+    #define ETH_STATIC_IP  192,168,1,50
+  #endif
+  #ifndef ETH_GATEWAY
+    #define ETH_GATEWAY    192,168,1,1
+  #endif
+  #ifndef ETH_SUBNET
+    #define ETH_SUBNET     255,255,255,0
+  #endif
+#endif
+
 bool RAK13800EthernetInterface::begin() {
+#ifdef WITH_W5100S_POE
+  // Non-disruptive only: the real bring-up runs from loop() after ETH_POE_DEFER_MS.
+  _startedAt = millis();
+  return true;
+#else
+  return bringUp();
+#endif
+}
+
+bool RAK13800EthernetInterface::bringUp() {
 
   // WB_IO2 (power enable) is already driven HIGH by early constructor
   // in RAK4631Board.cpp to support POE boot.
@@ -45,6 +75,14 @@ bool RAK13800EthernetInterface::begin() {
   IPAddress subnet(ETHERNET_STATIC_SUBNET);
   IPAddress dns(ETHERNET_STATIC_DNS);
   Ethernet.begin(mac, ip, dns, gateway, subnet);
+  #elif defined(WITH_W5100S_POE)
+  // Bounded DHCP with a static-IP fallback, so the node stays reachable without a
+  // DHCP server and never blocks indefinitely at cold start.
+  if (Ethernet.begin(mac, 12000, 4000) == 0) {
+    ETHERNET_DEBUG_PRINTLN("DHCP failed, using static IP fallback");
+    IPAddress ip(ETH_STATIC_IP), gw(ETH_GATEWAY), sn(ETH_SUBNET);
+    Ethernet.begin(mac, ip, gw, gw, sn);
+  }
   #else
   if (Ethernet.begin(mac) == 0) {
     ETHERNET_DEBUG_PRINTLN("Failed to initialize RAK13800 hardware.");
@@ -88,6 +126,14 @@ bool RAK13800EthernetInterface::isConnected() const {
 }
 
 void RAK13800EthernetInterface::loop() {
+#ifdef WITH_W5100S_POE
+  if (!_hwReady) {
+    if (millis() - _startedAt > ETH_POE_DEFER_MS) {
+      _hwReady = bringUp();
+    }
+    return;
+  }
+#endif
 
   Ethernet.maintain();
 

src/helpers/ethernet/RAK13800/RAK13800EthernetInterface.h

@@ -10,9 +10,20 @@ class RAK13800EthernetInterface : public SerialEthernetInterface {
   EthernetServer server;
   EthernetClient client;
 
+  bool bringUp();   // init the W5100S, obtain an IP and start listening
+
+#ifdef WITH_W5100S_POE
+  bool _hwReady;               // true once the (deferred) bring-up has run
+  unsigned long _startedAt;    // millis() at begin(); bring-up is deferred from here
+#endif
+
   public:
     RAK13800EthernetInterface() : server(EthernetServer(ETHERNET_TCP_PORT)) {
       _isConnected = false;
+    #ifdef WITH_W5100S_POE
+      _hwReady = false;
+      _startedAt = 0;
+    #endif
     }
 
     bool begin();

src/helpers/nrf52/EthernetCLI.h

@@ -27,6 +27,26 @@ static SPIClass ETHERNET_SPI_PORT(NRF_SPIM1, PIN_SPI1_MISO, PIN_SPI1_SCK, PIN_SP
 
 #define ETHERNET_RETRY_INTERVAL_MS 30000
 
+#ifdef WITH_W5100S_POE
+  // Give the RAK19018 (Silvertel) PoE converter time to latch on the current
+  // the W5100S is already drawing (board.begin()'s early RST release +
+  // bit-bang soft-reset) before doing the *disruptive* Ethernet-library
+  // bring-up (another PHY soft-reset + blocking DHCP) — doing that
+  // immediately reliably collapsed the marginal PoE supply.
+  #ifndef ETH_POE_DEFER_MS
+    #define ETH_POE_DEFER_MS 6000
+  #endif
+  #ifndef ETH_STATIC_IP
+    #define ETH_STATIC_IP  192,168,1,50
+  #endif
+  #ifndef ETH_GATEWAY
+    #define ETH_GATEWAY    192,168,1,1
+  #endif
+  #ifndef ETH_SUBNET
+    #define ETH_SUBNET     255,255,255,0
+  #endif
+#endif
+
 static EthernetServer ethernet_server(ETHERNET_TCP_PORT);
 static EthernetClient ethernet_client;
 static volatile bool ethernet_running = false;
@@ -35,6 +55,10 @@ static volatile bool ethernet_running = false;
 static void ethernet_task(void* param) {
   (void)param;
 
+#ifdef WITH_W5100S_POE
+  vTaskDelay(pdMS_TO_TICKS(ETH_POE_DEFER_MS));
+#endif
+
   Serial.println("ETH: Initializing hardware");
   // WB_IO2 (power enable) is already driven HIGH by early constructor
   // in RAK4631Board.cpp to support POE boot.
@@ -51,6 +75,22 @@ static void ethernet_task(void* param) {
   Serial.printf("ETH: MAC: %02X:%02X:%02X:%02X:%02X:%02X\n",
       mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 
+#ifdef WITH_W5100S_POE
+  // Bounded DHCP with a static-IP fallback, so the node stays reachable even
+  // without a DHCP server (no infinite retry — this build has no battery and
+  // must always come up somewhere).
+  Serial.println("ETH: Attempting DHCP...");
+  if (Ethernet.begin(mac, 10000, 2000) == 0) {
+    Serial.println("ETH: DHCP failed -> static IP fallback");
+    IPAddress ip(ETH_STATIC_IP), gw(ETH_GATEWAY), sn(ETH_SUBNET);
+    Ethernet.begin(mac, ip, gw, gw, sn);
+  }
+  IPAddress ip = Ethernet.localIP();
+  Serial.printf("ETH: IP: %u.%u.%u.%u\n", ip[0], ip[1], ip[2], ip[3]);
+  Serial.printf("ETH: Listening on TCP port %d\n", ETHERNET_TCP_PORT);
+  ethernet_server.begin();
+  ethernet_running = true;
+#else
   // Retry loop: keep trying until we get an IP
   while (!ethernet_running) {
     Serial.println("ETH: Attempting DHCP...");
@@ -75,8 +115,9 @@ static void ethernet_task(void* param) {
     ethernet_server.begin();
     ethernet_running = true;
   }
+#endif
 
-  // DHCP succeeded, task is done
+  // DHCP succeeded (or static fallback applied), task is done
   vTaskDelete(NULL);
 }
 

variants/rak4631/RAK4631Board.cpp

@@ -16,13 +16,24 @@ static void __attribute__((constructor(102))) rak4631_early_poe_power() {
 }
 #endif
 
+#ifdef WITH_W5100S_POE
+  #include "W5100SPoE.h"
+#endif
+
 #ifdef NRF52_POWER_MANAGEMENT
-// Static configuration for power management
-// Values set in variant.h defines
 const PowerMgtConfig power_config = {
   .lpcomp_ain_channel = PWRMGT_LPCOMP_AIN,
-  .lpcomp_refsel = PWRMGT_LPCOMP_REFSEL,
-  .voltage_bootlock = PWRMGT_VOLTAGE_BOOTLOCK
+  .lpcomp_refsel     = PWRMGT_LPCOMP_REFSEL,
+  // WITH_W5100S_POE = PoE operation without a battery.
+  // isExternalPowered() only detects USB VBUS, not PoE power.
+  // Without this exception checkBootVoltage() reads the floating
+  // battery ADC pin (no battery) and triggers the protection
+  // shutdown -> SYSTEMOFF loop -> red LED flicker.
+#ifdef WITH_W5100S_POE
+  .voltage_bootlock  = 0
+#else
+  .voltage_bootlock  = PWRMGT_VOLTAGE_BOOTLOCK
+#endif
 };
 
 void RAK4631Board::initiateShutdown(uint8_t reason) {
@@ -64,4 +75,19 @@ void RAK4631Board::begin() {
 #endif
   digitalWrite(SX126X_POWER_EN, HIGH);
   delay(10);   // give sx1262 some time to power up
-}
+
+#ifdef WITH_W5100S_POE
+  uint8_t w5100s_ver = w5100s_poe_init();
+  (void)w5100s_ver;
+  #ifdef MESH_DEBUG
+    // Wait for USB-CDC to re-enumerate so this line isn't eaten during the
+    // reconnect, then print it repeatedly to be sure it is seen. Debug only —
+    // the PoE production build skips this and boots fast.
+    delay(3000);
+    for (int i = 0; i < 5; i++) {
+      MESH_DEBUG_PRINTLN(">>> W5100S VERSIONR = 0x%02X (expect 0x51) <<<", w5100s_ver);
+      delay(200);
+    }
+  #endif
+#endif
+}

variants/rak4631/W5100SPoE.cpp

@@ -0,0 +1,97 @@
+#ifdef WITH_W5100S_POE
+
+#include <Arduino.h>
+#include <nrf.h>
+#include "W5100SPoE.h"
+
+// ── Early RST release (constructor priority 200) ─────────────────────────────
+// Runs before setup(), right after SystemInit — earlier than the ETHERNET_ENABLED
+// constructor in RAK4631Board.cpp that powers the peripheral rail (WB_IO2,
+// priority 102 runs first) but well before setup()/board.begin(), so the
+// W5100S starts drawing its full operating current as early as possible,
+// before the RAK19018 (Silvertel) converter's foldback timer expires.
+//
+// Raw registers because the Arduino GPIO layer isn't up this early.
+static void __attribute__((constructor(200))) w5100s_early_rst_release() {
+    // P0.21 = W5100S RST → HIGH (release from reset)
+    NRF_P0->PIN_CNF[21] =
+        (GPIO_PIN_CNF_DIR_Output       << GPIO_PIN_CNF_DIR_Pos) |
+        (GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos) |
+        (GPIO_PIN_CNF_PULL_Disabled    << GPIO_PIN_CNF_PULL_Pos) |
+        (GPIO_PIN_CNF_DRIVE_S0S1       << GPIO_PIN_CNF_DRIVE_Pos) |
+        (GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
+    NRF_P0->OUTSET = (1UL << 21);
+}
+
+// ── Bit-banged SPI to the W5100S ────────────────────────────────────────────
+// Shares the SPI bus (SCK=3 / MOSI=30 / MISO=29) with the SX1262 radio; only
+// the chip-select differs (W5100S CS=26, SX1262 NSS=42). Bit-banged so it
+// works regardless of which SPIClass owns the bus and runs before RadioLib.
+// W5100S frame: write [0xF0][hi][lo][data], read [0x0F][hi][lo]->[data].
+#define ETH_SCK_PIN   3
+#define ETH_MOSI_PIN  30
+#define ETH_MISO_PIN  29
+#define LORA_NSS_PIN  42
+
+static void bb_write_reg(uint16_t addr, uint8_t data) {
+    const uint8_t frame[4] = { 0xF0, (uint8_t)(addr >> 8), (uint8_t)(addr & 0xFF), data };
+    digitalWrite(W5100S_CS_PIN, LOW);
+    for (uint8_t b = 0; b < 4; b++) {
+        uint8_t v = frame[b];
+        for (int8_t i = 7; i >= 0; i--) {
+            digitalWrite(ETH_MOSI_PIN, (v >> i) & 1);
+            digitalWrite(ETH_SCK_PIN, HIGH);
+            digitalWrite(ETH_SCK_PIN, LOW);
+        }
+    }
+    digitalWrite(W5100S_CS_PIN, HIGH);
+}
+
+static uint8_t bb_read_reg(uint16_t addr) {
+    const uint8_t frame[3] = { 0x0F, (uint8_t)(addr >> 8), (uint8_t)(addr & 0xFF) };
+    digitalWrite(W5100S_CS_PIN, LOW);
+    for (uint8_t b = 0; b < 3; b++) {
+        uint8_t v = frame[b];
+        for (int8_t i = 7; i >= 0; i--) {
+            digitalWrite(ETH_MOSI_PIN, (v >> i) & 1);
+            digitalWrite(ETH_SCK_PIN, HIGH);
+            digitalWrite(ETH_SCK_PIN, LOW);
+        }
+    }
+    uint8_t out = 0;
+    for (int8_t i = 7; i >= 0; i--) {
+        digitalWrite(ETH_SCK_PIN, HIGH);
+        out = (out << 1) | (digitalRead(ETH_MISO_PIN) & 1);
+        digitalWrite(ETH_SCK_PIN, LOW);
+    }
+    digitalWrite(W5100S_CS_PIN, HIGH);
+    return out;
+}
+
+// ── Full W5100S bring-up ────────────────────────────────────────────────────
+// Called from RAK4631Board::begin(). Confirms RST is driven (Arduino API, in
+// case the core re-init touched it), then soft-resets and reads VERSIONR.
+// Returns VERSIONR (0x51 = healthy W5100S).
+uint8_t w5100s_poe_init() {
+    delay(20);  // let the rail/W5100S settle after the ETHERNET_ENABLED ctor's WB_IO2 enable
+
+    // Park both chip-selects HIGH on the shared bus, RST released.
+    pinMode(LORA_NSS_PIN,   OUTPUT); digitalWrite(LORA_NSS_PIN,   HIGH);
+    pinMode(W5100S_CS_PIN,  OUTPUT); digitalWrite(W5100S_CS_PIN,  HIGH);
+    pinMode(W5100S_RST_PIN, OUTPUT); digitalWrite(W5100S_RST_PIN, HIGH);
+
+    pinMode(ETH_SCK_PIN,  OUTPUT); digitalWrite(ETH_SCK_PIN, LOW);
+    pinMode(ETH_MOSI_PIN, OUTPUT); digitalWrite(ETH_MOSI_PIN, LOW);
+    pinMode(ETH_MISO_PIN, INPUT);
+
+    bb_write_reg(0x0000, 0x80);   // MR: software reset
+    delay(2);
+
+    uint8_t ver = bb_read_reg(0x0080);   // VERSIONR (0x51 on W5100S)
+
+    // Chip stays powered and out of reset; PHY auto-negotiates with the switch
+    // and the W5100S draws its full operating current.
+    return ver;
+}
+
+#endif // WITH_W5100S_POE

variants/rak4631/W5100SPoE.h

@@ -0,0 +1,36 @@
+#pragma once
+
+// W5100S early activation for PoE operation on RAK10720 (RAK4631 + RAK13800 +
+// RAK19018).
+//
+// ROOT CAUSE (confirmed via RAK forum + Meshtastic rak4631_eth_gw variant):
+// The RAK19018 PoE module (Silvertel Ag9905MT) enters a non-continuous
+// "gated pulse" mode when the load is below ~125-200 mA. A bare MeshCore
+// repeater draws only a few mA, so the converter never latches → the supply
+// pulses and the device never boots (fade-in / brighten / die / repeat LED).
+//
+// The fix: bring the W5100S PHY into its active state as early as possible.
+// An active W5100S draws ~120 mA — enough to keep the Silvertel converter
+// latched in continuous mode. The peripheral power rail (WB_IO2 / P1.02) is
+// already driven HIGH by an early constructor in RAK4631Board.cpp whenever
+// ETHERNET_ENABLED is set; this file only handles releasing RST (the rail
+// alone isn't enough — the chip must actually be brought out of reset and
+// made to draw its full current well before the Ethernet library's own
+// (later, disruptive) bring-up runs).
+//
+// Pin mapping (from Meshtastic rak4631_eth_gw variant.h):
+//   RST → PIN_ETHERNET_RESET = 21 (P0.21 / WB_IO3)
+//   CS  → PIN_ETHERNET_SS    = 26 (WB_SPI_CS)
+//   SPI → SPI1 (SCK=3, MISO=29, MOSI=30)   [not used in Layer 1]
+
+#ifndef W5100S_RST_PIN
+  #define W5100S_RST_PIN  21   // P0.21 / WB_IO3
+#endif
+
+#ifndef W5100S_CS_PIN
+  #define W5100S_CS_PIN   26   // WB_SPI_CS
+#endif
+
+// Called from RAK4631Board::begin(); fully brings up the W5100S (soft reset +
+// activation) so it draws full operating current. Returns VERSIONR (0x51 = ok).
+uint8_t w5100s_poe_init();