Pololu Motor Controller Daisy Chains

[kresty]

OK, I'm getting closer.  Now the RC controller is making the motors move.  

I have a few questions on the SMC settings:

1. What limits are you talking about in the previous post?
2. I set the following:
   SMC A - Input  Mode = RC
   SMC B - Input Mode = Serial/USB
   SMC C - Input Mode = Serial/USB
   SMC D - Input Mode = RC
   Since SMC D gets both RC inputs, do I need to configure RC Channel 2?
3. Is there anything in the Advanced Settings I should set?

Sorry for so many questions.  Once I have this all set, I plan on creating a detailed document for future builders.

Thanks in advance,
- Ross

No problem Glad you're making progress

All 4 need to be set to serial with my script, sorry, I think I was confused earlier.

They motor controllers won't do anything my themselves.  They'll still listen for RC signals, but won't do anything with them.  


The Arduino will ask through serial where the sticks are and then add the values together and then command the motor controllers through serial to move whichever way is appropriate.

So:

• RC RX tells SMC A & D what the R/C stick positions are....
  

• SMC A & D remember that information - but don't actually do anything with it.
  
• The Arduino sends a signal through the Tx lines saying "SMC A", what's the RC position?
  
• SMC A sends a reply through it's Tx line (to the Arduino's Rx line) saying whatever the value is.
  
• Ditto for SMC D and the other two channels.
  
• The Arduino adds them all together.
  
• The Arduino commands each SMC to set it's motor to the appropriate speed through it's TX line
  

Note that in order for the Arduino to talk to each SMC, it has to address them by #.  The bottom of the chart says which # it expects each SMC to be.  (A is 13, B is 14, C is 15, D is 16).  You have to configure that from the computer when programming the SMCs or else they won't listen when the Arduino calls out their number.  

You can prop up the droid on blocks so the wheels can turn freely.  (That might help if one motor seems to turn but not others, you can figure out which ones are doing what.)

Also note that the wires from the SMC to each motor need to be oriented the same way (otherwise some motors will go backwards and others frontwards).  Easiest to make sure each one is going the right way is to put it on blocks and then use the left stick to rotate.  All wheels should be going the same direction and speed then.  (And if backwards, flip the A/B wires for the backwards motor(s)).

It's cool someone else is using this script & stuff, thanks for helping me shake out the kinks in the instructions!