Aug. 12 Motor Turn Tests

How the motor(s) react can help us understand what can be expected from Lego HW.
(Test environments:  Lego Mindstorms (MS) SW; eCos LMS)
(Later?: various Lejos pkgs; RobotC)


Tests:
When multiple motors are told to turn at the same time... 

• Is there a delay so motors really start 1 after the other? (eCos LMS; Lego MS SW)
• When motors are told turn a specific angle - how accurate is it? (Lego MS SW)
• How do motor run when told to use a specific power % 
• once
• repeatly

Power to the motors initialized via the eCos I2C driver works and sending % power works.
Also using Forte basic Motor FB.


For Tacho using Lego FW as a starting example. eCos requires some changes so can't be exactly same, but counting edge changes using TC1 counter for now on just 1 motor.

Tried various turning tests of all 3 motors at same time to see if they really turn at the same rate.


eCos LMS Forte FBs: 
All 3 motors set to same rate, power command sent multiple times
   - motors turn at same rate
All 3 motors set to same rate,  power command sent once
  - motors turn at different rates 
    Possibly motor given command first turns faster, but hard to tell, which one is faster.


Lego Mindstorms SW 1.0 (w/ updates) with Firmware 1.29
3 motors in parallel connection with brake 
 - turn at same rate
3 motors selected in Motor block
- Motor A turns slower; Changed connections - so it was certain.
- Using 360 degrees or 1 Rotation switching motors - Motor A stops short of 1 Rotation.

(To be added motor turning with Lejos)

Now have an idea what to expect.


Success is when counter changes. Until we change eCos setting to use PIT for something else, can't use for all 3 motors.