fix: fix board hang after sequential setup loop

Author: x1unix

docs/flasher/script.js

@@ -61,6 +61,8 @@ const state = {
   isWriting: false
 };
 
+const delay = async (n) => await new Promise((resolve) => setTimeout(resolve, n));
+
 function setErrorMsg(msg) {
   errMsg.innerText = msg;
   setScene(scenes.error);
@@ -200,6 +202,7 @@ async function writePassword(value) {
       throw new Error(`Device acknowledged password length doesn't match (want: ${value.length}, got: ${val})`);
     }
 
+    await delay(500);
     setScene(scenes.finish);
     setTimeout(() => setScene(scenes.start), 3000);
   } finally {

include/utils.h

@@ -20,5 +20,6 @@ uint16_t getPasswdLen();
 void readPasswdStr(uint16_t len, uint8_t* dst);
 void savePasswd(uint16_t len, uint8_t* data);
 void wipePasswd();
+void reset();
 
 #endif

src/saga.cpp

@@ -55,6 +55,7 @@ class SetupSaga : public Saga {
   PromptReader m_reader;
   unsigned long m_prevMillis = 0;
   bool m_ledEnabled = false;
+  bool m_changed = false;
 
   void updateLedState(bool state) {
     m_prevMillis = millis();
@@ -95,6 +96,7 @@ class SetupSaga : public Saga {
     Serial.println();
 #endif
 
+    m_changed = true;
     savePasswd(result.len, result.data);
     state.pwdLen = result.len;
     if (state.pwdData != nullptr) {
@@ -108,11 +110,21 @@ class SetupSaga : public Saga {
   void enter(BoardState& state) override {
     Serial.begin(9600);
     updateLedState(true);
+    m_changed = true;
     m_reader.reset();
   }
 
   void leave(BoardState& state) override {
+    Serial.flush();
     Serial.end();
+
+    if (m_changed) {
+      // HACK: for some reason, board stuck in indeterminate state after a couple of sequential setup cycles.
+      // Rebooting device helps.
+      delay(250);
+      reset();
+    }
+
     m_reader.reset();
     digitalWrite(PIN_LED_SETUP, LOW);
   }

src/utils.cpp

@@ -1,3 +1,4 @@
+#include <avr/wdt.h>
 #include <Arduino.h>
 #include <EEPROM.h>
 #include "config.h"
@@ -61,3 +62,17 @@ void wipePasswd() {
     EEPROM.update(i, 0xFF);
   }
 }
+
+void reset() {
+#if defined(__AVR__)
+  wdt_disable();
+  wdt_enable(WDTO_15MS);
+  while (1) {}
+#elif defined(ESP32) || defined(ESP8266)
+  ESP.restart();
+#else
+  // Fallback for other architectures
+  void (*resetFunc)(void) = 0;
+  resetFunc();
+#endif
+}