Working on controlling the SSC32 from the Raspberry Pi

In light of the problems that I was having with reading the SSC32 pwm values from the Arduino, I thought that I might try and do the same via a serial interface to the RPi.  That is where I ran into difficulty, mostly because I was rather busy this weekend with other things.  I am trying to set up a serial terminal to communicate via a USB to RS232 interface cable to the SSC32 servo controller.  I first tried Screen but couldn't figure out how to get it to work, then I tried minicom.  I guess that I am just going to have to read up on these two programs in order to figure out the baud rate settings and commands.  I will probably try to do the same types of commands via a connection to my laptop.  But, I want to get it working on the RPi so that I can at least say it is part of the solution.  Remember, controlling the SSC32 and Mini-Maestro to move servos was not a problem, finding out the current pwm for a given servo was.

Command Testing for Serial Interface to Arduino

Ok, I have started implementing and testing the serial interface to the Arduino.  So far, I have coded the following sequences:

(1) 1/1/pinNumber/analogRate - to write an analog rate to a specific pin
(2) 1/2/pinNumber/digitalState - to write a digital state to a specific pin
(3) 2/1/pinNumber - to read an analog value from a specific pin (via serial)
(4) 2/2/pinNumber - to read the digital state from a specific pin (via serial)
(5) 3/1/servoPin - to read the current pose of a servo from a specific pin (not active)
(6) 3/2/servoPin/servoPose - to write a pose to a servo on a specific pin (not active)
(7) 3/3/servoPin - to detach a servo on a specific pin (not active)
(8) 3/4/servoNumber - to read the pose on a specific servo channel on the maestro
(9) 3/5/servoNumber/servoPWM - to set the pwm pose on a specific servo channel on the maestro
(10) 4/1/lowSweepIR/highSweepIR/speedSweepIR -

At first I had some problems trying to get servos to react.  I noticed that the servos were not zeroing at the beginning of the loop.  It turns out that my connection to the mini-maestro was not working.  After re-seating the connection everything started working correctly.

First test was the 3/5/servoNumber/servoPWM - worked correctly on two different servos (0 - for the Ultrasonic distance sensor, 6 - for the IR distance sensor).  I added some instrumentation via the LCD Panel and was able to see what the command was being interpreted as.  Servos moved, although there was a delay (I do have a one second feed in there).

Second test was to get the 3/4/servoNumber to work - although I could get some return values, they were not what I was expecting.  Need to do a little more homework on return values from the maestro and how I am able to read that through a serial interface.  I am getting absolutely nothing back from the Mini-Maestro.  I am even using code that I know works with the device (according to websites that have the listings).

Update: Am I up against a hardware problem?  If so, what is the least expensive way of implementing what I want.  Should I go back to the SSC-32?  The resolution in the analog domain was not that great, however, I am no longer using the Maestro to read the values from the IR or Ultrasonic distance sensors.