diff --git a/README.md b/README.md
index b69e027f3..32e8a9abf 100644
--- a/README.md
+++ b/README.md
@@ -179,8 +179,8 @@ The following devices are supported:
 - [iTead Sonoff Dual (R2)](https://www.itead.cc/smart-home/sonoff-dual.html)
 - [iTead Sonoff Pow with Energy Monitoring](https://www.itead.cc/smart-home/sonoff-pow.html)
 - [iTead Sonoff Pow R2 with Energy Monitoring](https://www.itead.cc/sonoff-pow-r2.html)
-- [iTead Sonoff 4CH](https://www.itead.cc/smart-home/sonoff-4ch.html)
-- [iTead Sonoff 4CH Pro](https://www.itead.cc/smart-home/sonoff-4ch-pro.html)
+- [iTead Sonoff 4CH (R2)](https://www.itead.cc/smart-home/sonoff-4ch.html)
+- [iTead Sonoff 4CH Pro (R2)](https://www.itead.cc/smart-home/sonoff-4ch-pro.html)
 - [iTead S20 Smart Socket](https://www.itead.cc/smart-socket.html)
 - [Sonoff S22 Smart Socket](https://github.com/arendst/Sonoff-Tasmota/issues/627)
 - [iTead Sonoff S31 Smart Socket with Energy Monitoring](https://www.itead.cc/sonoff-s31.html)
@@ -188,7 +188,7 @@ The following devices are supported:
 - [iTead Sonoff Touch](https://www.itead.cc/sonoff-touch.html)
 - [iTead Sonoff T1](https://www.itead.cc/sonoff-t1.html)
 - [iTead Sonoff SC](https://www.itead.cc/sonoff-sc.html)
-- [iTead Sonoff Led](https://www.itead.cc/sonoff-led.html)<img src="https://github.com/arendst/arendst.github.io/blob/master/media/sonoff4ch.jpg" height="250" align="right" />
+- [iTead Sonoff Led](https://www.itead.cc/sonoff-led.html)<img src="https://github.com/arendst/arendst.github.io/blob/master/media/sonoff4chpror2.jpg" height="250" align="right" />
 - [iTead Sonoff BN-SZ01 Ceiling Led](https://www.itead.cc/bn-sz01.html)
 - [iTead Sonoff B1](https://www.itead.cc/sonoff-b1.html)
 - [iTead Sonoff RF Bridge 433](https://www.itead.cc/sonoff-rf-bridge-433.html)
@@ -209,7 +209,7 @@ The following devices are supported:
 You can contribute to Sonoff-Tasmota by
 - providing Pull Requests (Features, Proof of Concepts, Language files or Fixes)
 - testing new released features and report issues
-- donating to acquire hardware for testing and implementating or out of gratitude
+- donating to acquire hardware for testing and implementing or out of gratitude
 
 [![donate](https://img.shields.io/badge/donate-PayPal-blue.svg)](https://paypal.me/tasmota)
 
diff --git a/sonoff/language/cs-CZ.h b/sonoff/language/cs-CZ.h
index fa641216d..51296a577 100644
--- a/sonoff/language/cs-CZ.h
+++ b/sonoff/language/cs-CZ.h
@@ -1,7 +1,7 @@
 /*
   cs-CZ.h - localization for Czech with diacritics - Czech for Sonoff-Tasmota
 
-  Copyright (C) 2018  Vladimír Synekl
+  Copyright (C) 2018  Vladimír Synek
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -368,7 +368,7 @@
 // xdrv_09_timers.ino
 #define D_CONFIGURE_TIMER "Nastavení Časovače"
 #define D_TIMER_PARAMETERS "Časovač"
-#define D_TIMER_ARM "Zajistit"
+#define D_TIMER_ARM "Aktivní"
 #define D_TIMER_TIME "Čas"
 #define D_TIMER_DAYS "Dny"
 #define D_TIMER_REPEAT "Opakovat"
diff --git a/sonoff/xsns_22_sr04.ino b/sonoff/xsns_22_sr04.ino
index 5a3a7dc87..59781cb0e 100644
--- a/sonoff/xsns_22_sr04.ino
+++ b/sonoff/xsns_22_sr04.ino
@@ -26,6 +26,7 @@
  * - https://www.dfrobot.com/wiki/index.php/Weather-proof_Ultrasonic_Sensor_SKU_:_SEN0207
 \*********************************************************************************************/
 #define max(a,b) ((a)>(b)?(a):(b))
+#define min(a,b) ((a)<(b)?(a):(b))
 
 uint8_t sr04_echo_pin = 0;
 uint8_t sr04_trig_pin = 0;
@@ -71,7 +72,7 @@ boolean Sr04Read(uint16_t *distance)
 uint16_t Sr04Ping(uint16_t max_cm_distance)
 {
   uint16_t duration = 0;
-  uint16_t maxEchoTime, maxTime;
+  uint16_t maxEchoTime;
 
   maxEchoTime = min(max_cm_distance + 1, (uint16_t) MAX_SENSOR_DISTANCE + 1) * US_ROUNDTRIP_CM;
 
@@ -89,7 +90,8 @@ uint16_t Sr04Ping(uint16_t max_cm_distance)
   return (duration > maxEchoTime) ? 0 : duration;
 }
 
-uint16_t Sr04GetSamples(uint8_t it, uint16_t max_cm_distance) {
+uint16_t Sr04GetSamples(uint8_t it, uint16_t max_cm_distance)
+{
   uint16_t uS[it];
   uint16_t last;
   uint8_t j;