diff --git a/README.md b/README.md
index dffbcf1..11758ff 100644
--- a/README.md
+++ b/README.md
@@ -12,12 +12,21 @@ In order to put the stirrer into operation you have to change the settings in st
 
 ## Reference
 
-This project was created based on an idea from the Hobbybrauer-Forum and would not be possible without the ideas from there.
+This project was created based on an idea from the german Hobbybrauer-Forum and would not be possible without the ideas from there.
 
 The forum: https://hobbybrauer.de/
 
 The thread: https://hobbybrauer.de/forum/viewtopic.php?f=21&t=1456
 
+Special thanks for development and testing:
+
+* Herbert Schmid 
+* Adrian Sigel
+* Jens Warkentin
+* Bastian Werner
+
+Successor project of: https://github.com/micworg/stir
+
 ## Overview of Functions
 
 All functions are controlled by the KY-040 encoder:
@@ -61,8 +70,8 @@ All functions are controlled by the KY-040 encoder:
 |`PWM2`|PWM output pin for LCD brightness control|
 |`I0`, `I1`|interrupts for rpm measurement (2 and 3 for Leonardo and ProMicro / 0 and 1 for Uno)|
 |`CLK`, `DT`, `SW`|pins for KY-040 encoder| 
-|`OFF0`, `OFF1`|these pins will be set if the fan is off| 
-|`OFFSTATE`|off state (LOW/HIGH)| 
+|`R0`, `R0`|voltage select relais pin| 
+|`OFFSTATE`|voltage switch threshold (rpm)| 
 |`RINTERVAL`|regulation interval (ms)|
 |`RDELAY`|extra regulation delay when value changes (ms)|
 |`RTOL`|regulation tolerance (rpm)|
@@ -73,71 +82,3 @@ All functions are controlled by the KY-040 encoder:
 |`SAVEDELAY`|delay in seconds before parameter will be saved to EEPROM|
 |`LCDB`|LCD brightness steps (10 values, 0=off, 255=max)|
 
-## API commands
-
-Commands are colon separated an can be send via USB/Serial
-
-|Command|Description|
-|:------|:----------|
-|`info`|returns a colon separated string with all parameters (see below)|
-|`version`|returns the software version|
-|`on:<0/1>`|switch stirren on|
-|`off:<0/1>`|switch stirren off|
-|`bon:<0/1>`|switch boost mode on|
-|`boff:<0/1>`|switch boost mode off|
-|`speed:<0/1>:<rpm>`|set stirrer speed (FANMIN-FANMAX rpm)|
-|`bspeed:<0/1>:<rpm>`|set stirrer boost speed (speed-FANMAX rpm)|
-|`btime:<0/1>:<min>`|set boost time (0-60)|
-|`con:<0/1>`|switch catch mode on|
-|`coff:<0/1>`|switch catch mode off|
-|`ctime:<0/1>:<min>`|set catch mode interval (60-240 min)|
-|`rtime:<0/1>:<sec>`|set speed rise time (0-240 sec)|
-|`rnval:<0/1>:<rpm>`|set randon value range (0-1000 rpm)|
-|`otime:<0/1>:<hour>`|switch stirrer off after time in hours (1-99 hour, 0 deactivates switch off)|
-
-All commands return a colon separated string with all current parameters:
-
-|Element|Stirrer|Variable in stir.ino|Description|
-|:------|:------|:-------------------|:----------|
-| 0|0|`F[0]`     |state (0=on, 1=off)|
-| 1|0|`v[0]`     |speed (rpm)|
-| 2|0|`b[0]`     |boost speed (rpm)|
-| 3|0|`rpm[0]`   |rpm|
-| 4|0|`xpm[0]`   |averaged rpm|
-| 5|0|`r[0]`     |regulation value|
-| 6|0|`bstate[0]`|boost state (0=on, 1=off)|
-| 7|0|`btime[0]` |boost time (min)|
-| 8|0|`cat[0]`   |fish catch mode state (0=on, 1=off)|
-| 9|0|`ctime[0]` |fish catch time interval (min)|
-|10|0|`rtime[0]` |speed rise time (sec)|
-|11|0|`otime[0]` |switch off time (hour)|
-|12|0|`rnval[0]` |random value range (rpm)|
-|13|0|`rnd[0]`   |current random value (rpm)|
-|14|0|           |boost remain (sec)|
-|15|0|           |off timer remain (sec)|
-|16|1|`F[1]`     |state (0=on, 1=off)|
-|17|1|`v[1]`     |speed (rpm)|
-|18|1|`b[1]`     |boost speed (rpm)|
-|19|1|`rpm[1]`   |rpm|
-|20|1|`xpm[1]`   |averaged rpm|
-|21|1|`r[1]`     |regulation value|
-|22|1|`bstate[1]`|boost state (0=on, 1=off)|
-|23|1|`btime[1]` |boost time (min)|
-|24|1|`cat[1]`   |fish catch mode state (0=on, 1=off)|
-|25|1|`ctime[1]` |fish catch time interval (min)|
-|26|1|`rtime[1]` |speed rise time (sec)|
-|27|1|`otime[1]` |switch off time (hour)|
-|28|1|`rnval[1]` |random value range (rpm)|
-|29|1|`rnd[1]`   |current random value (rpm)|
-|30|1|           |boost remain (sec)|
-|31|1|           |off timer remain (sec)|
-|32| |           |software version|
-|33| |           |uptime (ms)|
-|34| |           |0=ok, 1=error|
-
-## Schematics
-
-<p align="center">
-<img src="https://github.com/micworg/stir/blob/master/images/schematic_leonardo.png" width=500>
-<img src="https://github.com/micworg/stir/blob/master/images/schematic_uno.png" width=500>
-</p>
diff --git a/images/.DS_Store b/images/.DS_Store
new file mode 100644
index 0000000..5008ddf
Binary files /dev/null and b/images/.DS_Store differ
diff --git a/nanoshield/images/.DS_Store b/nanoshield/images/.DS_Store
new file mode 100644
index 0000000..5008ddf
Binary files /dev/null and b/nanoshield/images/.DS_Store differ
diff --git a/stir.ino b/stir.ino
index 9e7b895..14d6f2f 100644
--- a/stir.ino
+++ b/stir.ino
@@ -381,8 +381,11 @@ void slcd(int x,int y, int l,String s) { ///////////////////////////////////////
 }
 
 void calcramp(int i) { ///////////////////////////////////////////////////////////// calculate speed ramp value
-  xb[i]=b[i];if (bstate[i]) xb[i]=cut(((b[i]-v[i])/(rtime[i]*1000.0)*(MS-bts[i]))+v[i],v[i],b[i]);
-  xv[i]=v[i];xv[i]=cut(((v[i]-FANMIN)/(rtime[i]*1000.0)*(MS-vts[i]))+FANMIN,FANMIN,v[i]);
+  xb[i]=b[i];
+  int rt=rtime[i]?rtime[i]:1;
+  if (bstate[i]) xb[i]=cut(((b[i]-v[i])/(rt*1000.0)*(MS-bts[i]))+v[i],v[i],b[i]);
+  xv[i]=v[i];
+  xv[i]=cut(((v[i]-FANMIN)/(rt*1000.0)*(MS-vts[i]))+FANMIN,FANMIN,v[i]);
   if (rnval[i]>0 && xv[i]>=v[i]) xv[i]=cut(xv[i]+rnd[i],FANMIN,FANMAX);  
 }