RAMP SPEED Servo controller

RN

I am back again but with a new problem. Finally my servos are moving through serial commands thanks to stefan and mike.

I have a robotic arm(self made) in which i have three servos. As soon as the servo board is turned on the robotic arm is reset to default position but it moves to the initial speed at ramp speed of 0(max). I want to slow that down. the documentation has a new default position but that doesn't have a ramp speed as an option. where should i change it in the firmware

StefanL38

OK after looking inside the firmware into

PUB SetServoPosition            '' Set a new servo position
    Ramp := 0#>Ramp<#63
    If ((Enabled & |<Channel)>>Channel) == 1     '' Check if servo is enabled
       Servo.Set(Channel,0)        '' Disable Servo if servo flag is disabled 
    else
       If ServoRamp[noparse][[/noparse]Channel] == 0
          Servo.Set(Channel,500#> PW*2 <# 2500)
       Servo.SetRamp(Channel,500#> PW*2 <# 2500,RampSpeed[noparse][[/noparse]Ramp])
    ServoRamp[noparse][[/noparse]Channel] := Ramp
    ServoPosition[noparse][[/noparse]Channel] := PW   

I guess

you have to add

          Servo.SetRamp(temp,500#> PW*2 <# 2500,RampSpeed[noparse][[/noparse]"your-ramp-value"])                    

in the initilise loop sepction

''Initialize Loop ------------------------------------------------------------------

     repeat temp from 0 to 15   '' Initialize ALL servos to center position that are Enabled on Startup
       If ((Enabled & |<temp)>>temp) == 0               '' Check if servo is enabled on startup
          PW := 750                                     '' Set default Servo Width value
          If LoadDetect == 1                            '' Check if pre-defined Servo position has been selected
             PW_highbyte := EEPROM.RandomRead(ServoCh0+(temp<<1)+0)             '' Load pre-defined HIGH BYTE
             PW_lowbyte  := EEPROM.RandomRead(ServoCh0+(temp<<1)+1)             '' Load pre-defined LOW BYTE
             if PW < 250 or PW > 1250                   '' Check if pre-defined Servo position is within valid range 
                PW := 750                               '' ...If not default to center position
                
          'insert SetRamp-value here
          Servo.SetRamp(temp,500#> PW*2 <# 2500,RampSpeed[noparse][[/noparse]"your-ramp-value"])                    

          Servo.Set(temp,PW<<1)                         '' Initialize servo position

@Beau Schwabe from Parallax:
it would be very good if you add a pre-set value for the ramp and for servos enabled/disabled

best regards

Stefan

Beau Schwabe

StefanL38,

"it would be very good if you add a pre-set value for the ramp and for servos enabled/disabled"

- Why not just set the ramp to the same default "Set" position?

- With using the larger EEPROM, you can set the default servo position and if it's enabled or disabled. The Propeller Servo Controller USB firmware makes use of a feature similar to this. The PSC firmware just provides a wrapper for the Servo32 object


Example:

SERVO.Start
SERVO.Ramp

          'Set(Pin, Width)
SERVO.Set(ServoCh1,1500)

           'SetRamp(Pin, Width,Delay)<-- 100 = 1 sec 6000 = 1 min
SERVO.SetRamp(ServoCh1,1500,200)

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe

IC Layout Engineer
Parallax, Inc.

RN

a very strange problem is coming. Their is no effect of sending any ramp speed from 0-63 from the code. It is running at the same speed 0 but from the servo controller GUI their is effect of speed and it is running at specified speed. The code is as following

s=serial('com3','baud',2400);
s.readasyncmode='continuous';
s.timeout=2;
s.inputbuffersize=25555;
fopen(s);
X=[33,83,67,0,63,0,2,13];
fwrite(s,X,'char');
and I haven't made any change in the firmware

Andrey Demenev

There is no such thing as ramp speed for initial position. To perform smooth movement, servo controller needs to know current position. At startup, the position is unknown

Hugh

RN wrote: »

I have a robotic arm(self made) in which i have three servos.

Are you a T1000 Terminator by any chance?