3.8.4

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.8.4] 4 August 2026
+
+## Fixed
+
+- Allow auto-download and install of firmware versions which are smaller to allow update to the latest 3.9.0-development version.
+
 ## [3.8.3] 1 August 2026
 
 ## Added

src/core/system.cpp

@@ -3024,18 +3024,24 @@ bool System::uploadFirmwareURL(const char * url) {
         return false; // error
     }
 
+    // the Content-Length from the response header, -1 if the server didn't send one.
     int firmware_size = http.getSize();
+    if (firmware_size <= 0) {
+        LOG_ERROR("Firmware upload failed - unknown size");
+        http.end();
+        return false; // error
+    }
 
-    // check we have a valid size
-    if (firmware_size < 2097152) { // 2MB or greater is required
-        LOG_ERROR("Firmware upload failed - invalid size");
+    // catch a wrong URL early, before streaming. Smallest shipped image is ~1.9MB
+    if (firmware_size < 1677721) { // 1.6MB
+        LOG_ERROR("Firmware upload failed - too small (%d KB)", firmware_size / 1024);
         http.end();
         return false; // error
     }
 
     // check we have enough space for the upload in the ota partition
     if (!Update.begin(firmware_size)) {
-        LOG_ERROR("Firmware upload failed - no space");
+        LOG_ERROR("Firmware upload failed - %s", Update.errorString());
         http.end();
         return false; // error
     }
@@ -3052,7 +3058,7 @@ bool System::uploadFirmwareURL(const char * url) {
 
     // get tcp stream and send it to Updater
     WiFiClient * stream = http.getStreamPtr();
-    if (Update.writeStream(*stream) != firmware_size) {
+    if (Update.writeStream(*stream) != (size_t)firmware_size) {
         LOG_ERROR("Firmware upload failed - size differences");
         http.end();
         EMSESP::system_.systemStatus(SYSTEM_STATUS::SYSTEM_STATUS_ERROR_UPLOAD);

src/emsesp_version.h

@@ -1 +1 @@
-#define EMSESP_APP_VERSION "3.8.3"
+#define EMSESP_APP_VERSION "3.8.4"