Drive Motor and Encoder continued
The previous subroutine will START the drive motor. You can monitor the progress of the drive wheel by reading the encoder counter from the coprocessor. Here is example code that will read the encoder.
ec var word | 'Encoder | count. | |
serout net,baud,["!1E1"] | 'Ask | for | encoder count. |
serin net,baud,[hex4, ec] | 'Get | encoder count into ec. | |
You can use this code within a loop to wait until the desired distance is completed. Put a 100 ms delay between reads using a pause 100 command.
Steering Motor
The steering is an RC (remote control) style servo motor that is commonly used on model race cars and airplanes. The coprocessor can control 4 RC servo motors - #1 is used for steering. When the Basic Stamp II needs to control an RC servo motor, it simply sends a command to the coprocessor which han- dles the task. This frees up the Basic Stamp II for other tasks.
Here is a subroutine that can be used to control all 4 RC servo motors including the steering motor #1. Study the WANDER and TEST programs for additional insight.
'Constants and Variables. |
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net con 8 | 'coprocessor | network pin. | |
baud con | 396 | 'coprocessor | baud rate. |
position | var byte | 'Position of | motor. |
motor var byte | 'Motor #. |
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'Subroutine | to control RC servo motors. |
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'Motor # |
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'Position = |
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'The servo is moved to the desired position for 500 ms | |||
'then turned off to conserve power. |
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' |
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rcservo: |
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serout | net,baud,["!1R", dec1 motor, hex2 position] 'Move Motor. | ||
serin net,baud,[charn] | 'Get A. | ||
pause 500 | 'Wait for servo to turn. | ||
serout | net,baud,["!1R", dec1 motor, "00"] | 'Motor off. | |
serin net,baud,[charn] | 'Get A. | ||
return |
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If you need your RC servo motor to resist movement after it has turned to the desired position, don’t turn
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