Controlling 2 Motors With a Standard RC Receiver & 1 Dual Axis Joystick
RCIC-2
The RCIC-2 (Radio Control Interface Chip) is a preprogrammed PIC which will accept a standard 1 to 2 ms RC pulse from each of 2 channels and send the proper control signals to each of 2 MC7s to enable you to have full control of the direction and continuously variable speed of each controller. This gives you a 30 amp dual channel radio controlled Electronic Speed Control with full mixing for left/right and forward/reverse.
What this means is that, without any programming on your part, you can control the direction of your robot with the single dual axis joystick found on your standard RC transmitter. If you push the stick straight forward, both motors will go forward at the same speed. If you pull it straight back, both motors will go in reverse at the same speed, if you put the joystick straight to the right the left motor will go forward and the right motor will go reverse at the same speed causing your robot to turn on center to the right. If you put the joystick straight to the left, the left motor will go reverse and the right motor will go forward at the same speed causing your robot to turn on center to the left. If you are going straight forward, and you move the stick a little to the right (for example), the left wheel maintains whatever speed it was at while the right wheel slows down by an amount determined by how far you pushed the joystick to the right. This gives you the ability to make slow, wide turns or sharp turns right up to spinning on center. You always have full control of speed and direction.
Below, is a schematic diagram of the RCIC-2. To see a clearer schematic in .pdf format,
click HERE.
Table 1 RCIC-2 RC Control Chip Pinout Description
|
Pin Number |
Pin Name |
Purpose |
Connection |
|
1 |
RA2 |
Accepts CH2 pulse widths from 1 to 2 ms |
From RC receiver CH2 (Left-Right) |
|
2 |
RA3 |
Accepts CH1 pulse widths from 1 to 2 ms |
From RC receiver CH1 (Foward-Reverse) |
|
3 |
RA4 |
Not Used |
No Connection |
|
4 |
MCLR |
10K resistor connected to this pin |
Other side of 10K resistor connected to +5V. |
|
5 |
VSS |
Ground lead |
Connected to ground |
|
6 |
RB0 |
PWM output port for the MC7 board #1 |
Connected to the PW tab of the MC7 board #1 |
|
7 |
RB1 |
PWM output port for the MC7 board #2 |
Connected to the PW tab of the MC7 board #2 |
|
8 |
RB2 |
Outputs a logic level 1 (+5V) when the CH1 input pulse is less than 1.5 ms. |
Connected to the REV tab on the MC7 board #1 |
|
9 |
RB3 |
Outputs a logic 1 (+5V) when the CH1 input pulse is 1.5 ms +/- dead band |
Connected to an LED & resistor which lights to show when received pulse is 1.5 ms |
|
10 |
RB4 |
Outputs a logic 1 (+5V) when the CH1 input pulse is more than 1.5 ms |
Connect to the FWD tab on the MC7 board #1 |
|
11 |
RB5 |
Outputs a logic 1 (+5V) when the CH2 input pulse is 1.5 ms +/- dead band |
Connected to an LED & resistor which lights to show when received pulse is 1.5 ms |
|
12 |
RB6 |
Outputs a logic 1 (+5V) when receiving RC pulses |
Connected to an LED & resistor which lights to show when receiving pulses |
|
13 |
RB7 |
Not Used |
No Connection |
|
14 |
VDD |
+5V |
Connect to SW COM on the MC7 board #1 for a 5V source. |
|
15 |
OSC2 |
Connection for external frequency element |
Connect to supplied 10 MHz ceramic resonator. |
|
16 |
OSC1 |
Connection for external frequency element |
Connect to supplied 10 MHz ceramic resonator |
|
17 |
RA0 |
|
Connect to the FWD tab on the MC7 board #2 |
|
18 |
RA1 |
Outputs a logic 1 (+5V) when the CH2 input pulse is less than 1.5 ms. |
Connected to the REV tab on the MC7 board #2 |
RCIC-2 Daughterboard
RCIC-2 Daughterboard Close-Up
RCIC-2 Trace Side Showing Mating .250 PCB Mounted Receptacles
RCIC-2 Shown mounted on the first MC7 controller. Note connections for RC receiver on the right and connections for the 2nd MC7 on the left.
RCIC-2 shown mounted on the 1st MC7 with connections going to the 2nd MC7. At this point, all you need is an RC receiver, batteries and 2 motors. (See connection diagram shown below)
Connecting to Your Receiver
Recognizing that different brands of RC receivers have different connectors, I am including 4 universal leads (one red for the +5V connection, one black for the negative connection, 1 white for channel 1 output and 1 yellow for channel 2 output) with the RCIC-2. These leads will enable you to connect to your receiver regardless of what brand you own. YOU ARE RESPONSIBLE FOR BEING FAMILIAR WITH YOUR RECEIVER PIN CONNECTIONS AND CONNECTING THESE WIRES TO THE PROPER POINTS. The easiest thing to do is inspect the leads of the servos that came with your receiver. The color of the wires on the servo should tell you which pin is positive, negative and signal on your receiver. If you have any doubts, ask someone who is familiar with your receiver.
RCIC2_SC and JSIC interfaces are $45 each
Diverse Electronic Services
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