<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[🔥 Get Help]]></title><description><![CDATA[Stuck? Post here. Search the Troubleshooting Index first.]]></description><link>https://forum.grapesiot.com/category/18</link><generator>RSS for Node</generator><lastBuildDate>Wed, 22 Jul 2026 09:21:24 GMT</lastBuildDate><atom:link href="https://forum.grapesiot.com/category/18.rss" rel="self" type="application/rss+xml"/><pubDate>Wed, 22 Jul 2026 06:23:31 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[🔍 Troubleshooting Index — Error Messages & Solutions [SEARCH HERE FIRST]]]></title><description><![CDATA[Troubleshooting Index
Search this page (Ctrl+F) for your error message before posting.

GrapesIDE &amp; Toolchain



Error
Cause
Solution




A fatal error occurred: Failed to connect to ESP32
Board not in flash mode
Hold BOOT button while clicking Upload


No serial port found
Driver not installed
Install CH340 or CP2102 driver


Sketch too large
Binary exceeds flash
Change Partition Scheme to "No OTA (2MB)"


'x' was not declared in this scope
Missing #include or typo
Add the correct header file


implicit conversion loses integer precision
Type mismatch
Cast explicitly or fix variable type


warning: unused variable
Variable declared but never used
Remove or use the variable. Enable -Werror — this must be fixed




ESP32 Hardware



Error / Symptom
Cause
Solution




ADC reads 0 or noise during WiFi
ADC2 conflicts with WiFi
Switch to ADC1 channels (GPIO32-39)


GPIO reads random values (floating)
No pull-up/pull-down
Add 10kΩ pull-up or enable internal pull-up


Device resets randomly
Brownout — supply voltage too low
Measure VCC under load. Use better USB cable/adapter


Serial output garbled
Wrong baud rate in monitor
Match Serial.begin() rate exactly


LED on but dim
GPIO current limit exceeded
Add current-limiting resistor




FreeRTOS



Error / Symptom
Cause
Solution




Guru Meditation Error: Core panic'd
Stack overflow, null deref, WDT
Decode with addr2line — see Block 2 Crash Lab


Task watchdog got triggered: taskName
Task running without vTaskDelay
Add vTaskDelay(pdMS_TO_TICKS(1)) in loop


Device freezes randomly
Deadlock between mutexes
Check mutex acquisition order — always same order across tasks


assert failed: queue.c
Queue full with no space
Increase queue size or consume faster


Device reboots every N seconds
WDT not being reset
Add esp_task_wdt_reset() or vTaskDelay in busy tasks




MQTT &amp; Connectivity



Error / Code
Cause
Solution




PubSubClient state -2 (CONNECT_FAILED)
Wrong credentials or broker down
Check username/password/token


PubSubClient state -4 (TIMEOUT)
Wrong broker IP/port, firewall
Verify host, port 8883 for TLS


PubSubClient state 5 (UNAUTHORIZED)
ACL blocked the topic
Check topic matches your device_id exactly


TLS certificate verify failed
Wrong CA cert or device clock wrong
Sync NTP before TLS connect


TLS handshake timeout
Heap too low for TLS
Need &gt;50KB free heap — check esp_get_free_heap_size()


WiFi connects but MQTT fails
TLS port blocked by ISP/router
Try port 8083 (WS) or check firewall rules


Messages not arriving
QoS mismatch
Check publisher and subscriber QoS match




GrapesIoT Platform



Symptom
Cause
Solution




Device shows offline in dashboard
LWT not configured or WiFi down
Check MQTT connection and LWT topic


OTA command sent but device ignores
Device not subscribed to /down/#
Check subscription in firmware


Dashboard shows old data
Retained message from previous session
Clear retained by publishing empty payload


Alarm not triggering
Wrong field path in rule config
Check dot-notation path matches payload key




GrapesIDE Specific



Issue
Solution




Autocomplete not working
Restart IntelliSense: Ctrl+Shift+P → Reload Window


Board not detected on Mac
Allow USB accessories in System Settings → Privacy


Build slow
Exclude .pio folder from antivirus




Last updated by instructor. Post below if you have a new error+solution to add.
]]></description><link>https://forum.grapesiot.com/topic/12/troubleshooting-index-error-messages-solutions-search-here-first</link><guid isPermaLink="true">https://forum.grapesiot.com/topic/12/troubleshooting-index-error-messages-solutions-search-here-first</guid><dc:creator><![CDATA[admin]]></dc:creator><pubDate>Wed, 22 Jul 2026 06:23:31 GMT</pubDate></item></channel></rss>