How To Radio Control DC Motors Cheaply


List Of The Commands


There are 32 commands that the interface chip understands. All the commands are 3 bytes or 24 bits long. The format for the commands are as follows.

The 1st byte that is sent is always the command byte which is the left most number on the list below.

The 2nd byte sent may be a PWM byte. It is a number between 0 and 50. When a 0 is sent the P.W.M. pulse is low which means the motor will be off. When the number 50 is sent the P.W.M. pulse is high which means the motor will be on at full power. When the number 25 is sent the motor will run at about half power. As seen on the list sometimes the 2nd byte is just 0 which is being used just for a place holder. It has no affect on the motor.

The 3rd byte sent may be a PWM byte or an error checking number.

For example: To order motor 1 to go at full speed and motor 2 to go at half speed forward, the command would be.
1 50 25

To order motor 7 to go backward at 10% power, the command would be.
16 5 16

1     Motor 1 & 2 forward, PWM #, PWM #   (no error checking)
2     Motor 1 & 2 backward, PWM #, PWM #   (no error checking)
3     Motor 1 forward, PWM #, 3
4     Motor 1 backward, PWM #, 4
5     Motor 2 forward, PWM #, 5
6     Motor 2 backward, PWM #, 6
7     Motor 3 forward, PWM #, 7
8     Motor 3 backward, PWM #, 8
9     Motor 4 forward, PWM #, 9
10   Motor 4 backward, PWM #, 10
11   Motor 5 forward, PWM #, 11
12   Motor 5 backward, PWM #, 12
13   Motor 6 forward, PWM #, 13
14   Motor 6 backward, PWM #, 14
15   Motor 7 forward, PWM #, 15
16   Motor 7 backward, PWM #, 16
17   Motor 8 forward, PWM #, 17
18   Motor 8 backward, PWM #, 18
19   All motors speed, PWM #, 19
20   Motor 1 & 2 speed, PWM #, PWM #   (no error checking)
21   Motor 1 & 2 stop, X, 21   (pins low)
22   Motor 1 stop, 0, 22   (pins low)
23   Motor 2 stop, 0, 23   (pins low)
24   Motor 3 stop, 0, 24   (pins low)
25   Motor 4 stop, 0, 25   (pins low)
26   Motor 5 stop, 0, 26   (pins low)
27   Motor 6 stop, 0, 27   (pins low)
28   Motor 7 stop, 0, 28   (pins low)
29   Motor 8 stop, 0, 29   (pins low)
30   All motors stop, 0, 30   (pins low)
31   Pin 14 high, 0, 31
32   Pin 14 low, 0, 32


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