Servo signal (from ssc32) to 0-5k ohm signal

Lynxmotion Electronics & Software
1

I want to control a Motor Speed Controller with the SSC-32. The throttle and brake operate via Analog Brake and Throttle Input: 0-5 Volts. Producing 0-5V signal with 3-wire pot.
newkellycontroller.com/produ … cts_id=263

The website below sold exactly what I was looking for but unfortunately it has been discontinued because they were unable to source certain parts for the board to make them.

“RCA Analog Interface” for $48.00
Use this board to interface between your RC receiver and large speed controls that are not already set up for radio-controlled operation.

Does anyone know of anyone else that makes something like this or another way it could be done?

2

Is there some reason you want to use the SSC-32? Maybe other servos to control?

Otherwise, I’d just use a BB2, and run an D/A from the I2C output. Two channels of D/A would give you the 0-5V, or so for two channels.

Tell us more!

Alan KM6VV

3

Not super slick or high tech, but you could use a small servo to turn your 5k pot similar to my switch setup below until you can find something better.

http://web.comporium.net/~shb/pix/sw2.jpg
http://web.comporium.net/~shb/pix/sw5.jpg

4

I’m going to have several R/C Switches for blinkers, brakes, and headlights. I also have two rear mounted cameras that I want to be able to rotate with servos.
ant-systems.net/Product.asp?id=407

5

I found another possible solution:
#1 Astro Flight servo tester
#2 Dimention Engineering VHV BEC (Very High Voltage Battery Eliminator Circuit)
#3 Magura twist grip E-throttle
endless-sphere.com/forums/vi … 16&t=12261
http://www.endless-sphere.com/forums/download/file.php?id=25703

6

I copied this code directly from the manual (page 143). It looks like it would do what I want but I get a syntax error on this line:
pwm p1, duty, duration

Error: FILE C:\USERS\DYL\DOCUMENTS\DOWNLOADS\BASICATOM\THROTTLE.BAS(LINE 17) : [TOKEN :] : Unexpected argument type

I have a Basic Atom Pro 28. I’m not sure why I’m getting this error. I’m using version 1.0.0.15 of the IDE.

duty var byte
duration var word
duration=5000
main
duty=0
gosub generate
duty=64
gosub generate
duty=128
gosub generate
duty=192
gosub generate
duty=255
gosub generate
goto main
generate
pwm p1, duty, duration
return

With a filter such as that shown above, this program will generate, in
sequence, voltages of 0V, 1.15V, 2.3V, 3.45V and 4.6V for 5 seconds

7

I foyu only need two(or three) why not use hpwm instead? Pins P9,P10 and P11. You can set it and forget it(attribute to Ron Popile as necessary).

8

I tried hpwm on pin12. Then I took readings for voltage but nothing was changing. I’ll try it on P11.

What pins on #14 do I check for voltage with a multimeter to make sure it’s working correctly?

9

I tried setting up the filter per the manual and used HPWM instead of PWM on P11. I only get 4.47 volts or 0. I’m thinking that means my filter isn’t working. Has anyone else done this?

The Capacitor is:
Radio Shack part # 272-1053
Metalized-Film Capacitor
Radial leads - 250WVDC max
Tolerance ± 10%

Per the manual:
The output of the PWM command must be integrated (using a low
pass filter) to produce an analog voltage. A circuit such as the one
shown below will suffice for most uses.
http://www.otherrobots.com/lynxmotion/AnalogConverterPWMDiagram.bmp
The values of capacitor, series resistor (RS) and load resistor (RL)
may be varied to produce the desired output voltage and response
time. The values shown produce adequate filtering. Note that
response time is relatively slow, and the PWM command with a filter
such as this is mainly suitable for producing steady-state voltages
rather than rapidly varying waveforms.
The values shown will produce a voltage that varies linearly from 0V
(with duty set to 0) to approximately 4.6V (with duty set to 255). The
frequency of the pwm signal is approximately 125 kHz with duty set to
128 (50%) and drops significantly at both higher and lower duty
cycles.

duty var byte
duration var word
duration = 5000

main
  PAUSE 1000 
duty=0
gosub generate
duty=64
gosub generate
duty=128
gosub generate
duty=192
gosub generate
duty=255
gosub generate
goto main

generate
   serout S_OUT, i9600, [dec duty, 13] 'output to com port
sound P9,[10\51.913]
low P9

hPWM p11, duty, duration
'PWM p12, 0, 5000
sound P9,[10\1046.502]
low P9
  PAUSE 10000 
return

http://www.otherrobots.com/lynxmotion/PWMPot.jpg

10

I tried a different capacitor and it still didn’t work. Then I changed the duration to 100 and it started working! :open_mouth:

duty var byte
duration var word
'duration = 5000
duration = 100

main
  PAUSE 1000 
duty=0
gosub generate
duty=64
gosub generate
duty=128
gosub generate
duty=192
gosub generate
duty=255
gosub generate
goto main

generate
   serout S_OUT, i9600, [dec duty, 13] 'output to com port
sound P9,[10\51.913]
low P9

hPWM p11, duty, duration
'PWM p12, 0, 5000
sound P9,[10\1046.502]
low P9
  PAUSE 10000 
return
11

Also working with my original capacitor so duration to 100 is what did it.

12

These are my readings:
0 = 0v
64 = 4.47v
128 = 3.499v
192 = 2.340v
255 = 1.765v