Radio Control Interface Circuit, Self-Calibrating

The RCIC2_SC is the next generation of RCIC2. With a bigger microprocessor (PIC16F873 instead of the PIC 16F84) The almost 4 times larger memory capacity allowed for the inclusion of a self-calibrating routine. What this means is: this: On the original RCIC-2, if your RC transmitter, with it's joystick at center position, did not put out an "industry standard" 1.5 ms pulse, you had to adjust the trim for that channel to compensate (as indicated by the "center" LED on the RCIC-2 coming on). If your transmitter was way off, it was possible that you had to adjust your trim control for that channel all the way toward one extreme to get the "center" LED for that channel to come on. This was because the RCIC-2 was programmed to consider 1.5 ms. +/- a small dead band as "center" and presumed that manufacturers would make their equipment adhere to that "standard". It appears that some manufacturers do, some don't..
With the RCIC2_SC, this is no longer a consideration. When the RCIC2_SC is first turned on, it checks both channels for their value representing "center". (That's why it is important to make sure that the joystick and trims are resting at mechanical center, no matter what value pulse that represents, when the RCIC2_SC is first turned on). It then considers that value as center for all subsequent calculations when determining the joystick position.
The RCIC2_SC (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. What's even better is that you no longer have to hope that your RC transmitter is putting "standard" 1.5 ms pulses when the joystick and trims are set at center. As explained above, the RCIC2-SC will self calibrate to your transmitter when it is turned on.
The RCIC2_sc can also be special ordered with no mixing for those of you that are not steering robts or ROV's. In this version, pushing a dual axis joystick forward on the vertical axis makes motor #1 go in one direction, and the speed is controlled by how far you push the joystick forward. Pulling back on the joystick makes motor #1 go in the opposite direction, and the speed is controlled by how far the joystick is pulled back. There is no control over motor #2 unless you move the joystick off the center axis (+/- a small deadband). Moving the stick left or right on the horizontal axis while keeping centered on the vertical axis will cause motor #2 to respond in a similar fashion as just explained for the vertical axis. This is useful in applications such as pan and tilt for a telescope etc. You must specifically ask for this option when ordering or you will be sent the PIC on the board with the mixing version. There is no difference in price and the self calibrating feature is retained in either case.
Below is the schematic of the RCIC2_SC

RCIC_SC RC Control Pinout Table
|
Pin Number |
Pin Name |
Purpose |
Connection |
|
1 |
MCLR |
10K resistor connected to this pin |
Other side of 10K resistor connected to +5V. |
|
2 |
RA0 |
Not used |
No Connection |
|
3 |
RA1 |
Not used |
No Connection |
|
4 |
RA2 |
Not used |
No Connection |
|
5 |
RA3 |
Not used |
No Connection |
|
6 |
RA4 |
Not used |
No Connection |
|
7 |
RA5 |
Not used |
No Connection |
|
8 |
VSS |
Ground Lead |
Connected To Ground |
|
9 |
OSC1 |
Connection for external frequency element |
Connect to 10 MHz ceramic resonator |
|
10 |
OSC2 |
Connection for external frequency element |
Connect to 10 MHz ceramic resonator |
|
11 |
RC0 |
Accepts CH1 pulse widths from 1 to 2 ms |
From RC receiver CH1 |
|
12 |
RC1 |
Accepts CH1 pulse widths from 1 to 2 ms |
From RC receiver CH2 |
|
13 |
RC2 |
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 |
|
14 |
RC3 |
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 |
|
15 |
RC4 |
Outputs a logic 0 (Gnd) 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 |
|
16 |
RC5 |
Outputs a logic 0 (Gnd) when receiving RC pulses |
Connected to an LED & resistor which lights to show when receiving pulses |
|
17 |
RC6 |
Outputs a logic 0 (Gnd) 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 |
|
18 |
RC7 |
Serial out port, used for testing only |
Not Used |
|
19 |
VSS |
Ground lead |
Connected to ground |
|
20 |
VDD |
+5V |
Connect to SW COM on the MC7 board #1 for a 5V source. |
|
21 |
RB0 |
Not Used |
No Connection |
|
22 |
RB1 |
No signal/calibration Indicator |
Flashes ~1X/sec when no sig., flashes rapidly while calibrating, off otherwise |
|
23 |
RB2 |
Outputs a logic 1 (+5V) when the CH2 input pulse is more than 1.5 ms |
Connect to the FWD tab on the MC7 board #2 |
|
24 |
RB3 |
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 |
|
25 |
RB4 |
PWM output port for the MC7 board #2 |
Connected to the PW tab of the MC7 board #2 |
|
26 |
RB5 |
PWM output port for the MC7 board #1 |
Connected to the PW tab of the MC7 board #1 |
|
27 |
RB6 |
Not Used |
No Connection |
|
28 |
RB7 |
Not Used |
No Connection |
RCIC2_SC 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.
RCIC2_SC connection diagram

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_sc. These leads will enable you to connect to your receiver regardless of what brand you own. The color of the wires on the servos that came with your RC set should tell you the function of each pin on your receiver.
The RCIC2_SC is available for $45.00.



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