diff --git a/data_embed/index.html b/data_embed/index.html
index c2e2baf..ff3ba1a 100644
--- a/data_embed/index.html
+++ b/data_embed/index.html
@@ -147,7 +147,7 @@
                 </div>
                 <div>
                     <label for="shutdown_dt">Auto power off delay (s)</label>
-                    <input name="shutdown_dt" id="shutdown_dt" type="number" min="3" max="300" title="auto shutdown delay in seconds">
+                    <input name="shutdown_dt" id="shutdown_dt" type="number" min="3" max="3600" title="auto shutdown delay in seconds">
                 </div>                               
             </div>                      
             <div class="grid-container full">
diff --git a/platformio.ini b/platformio.ini
index 5555804..1d66e4a 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -9,7 +9,6 @@
 ; https://docs.platformio.org/page/projectconf.html
 
 [env]
-platform = espressif32
 framework = arduino
 
 monitor_speed = 115200
@@ -32,21 +31,26 @@ lib_deps =
 	SparkFun u-blox Arduino Library
 
 [env:ttgo-t-beam-v1.0]
+platform = espressif32 @ 3.0.0
 board = ttgo-t-beam
-build_flags = ${env.build_flags} -DT_BEAM_V1_0
+build_flags = ${env.build_flags} -D T_BEAM_V1_0
 
 [env:ttgo-t-beam-v0.7]
+platform = espressif32 @ 3.0.0
 board = ttgo-t-beam
-build_flags = ${env.build_flags} -DT_BEAM_V0_7
+build_flags = ${env.build_flags} -D T_BEAM_V0_7
 
 [env:ttgo-lora32-v2.1]
+platform = espressif32
 board = ttgo-lora32-v21
-build_flags = ${env.build_flags} -DLORA32_21
+build_flags = ${env.build_flags} -D LORA32_21
 
 [env:ttgo-lora32-v2]
+platform = espressif32
 board = ttgo-lora32-v2
-build_flags = ${env.build_flags} -DLORA32_2
+build_flags = ${env.build_flags} -D LORA32_2
 
 [env:ttgo-lora32-v1]
+platform = espressif32
 board = ttgo-lora32-v1
-build_flags = ${env.build_flags} -DLORA32_1
\ No newline at end of file
+build_flags = ${env.build_flags} -D LORA32_1
\ No newline at end of file