Simple 4A driver board for 18M2.

[WHITEKNUCKLES]

Looking at my previous thread about this driver board I see that I failed to show the simplicity of using it and must have turned away those who have no interest in altering hardware. My hope is that starting a new thread with a more appropriate title might recapture the interest of those who could take advantage of it's versatility and current carrying capacity by using the 18M2.

This board is simple to use, just replace the original 18 pin micro with an 18M2.
It can handle motors and other loads up to a total of about 4A.

With a programmed 18M2 replacing the original micro the board can control any of the following.

4 individual DC motors in one direction...Tested one motor repeated start/stop on 4 outputs.
2 motors in both directions..................Tested 2 motors repeated run/reverses on 2 paired outputs.
4 solenoids or high power relays...........Tested on a 'NEW' Elmic Compact Escapement on 4 outputs
4 heaters or lamps.............................Tested 12v 21w repeated on/off 1 lamp on 4 outputs.
1 bipolar stepper motor.......................Tested extensively.

None of the above require any alteration to the board to allow the 18M2 program to control them.

If the program requires input there are 4 pins on the input socket that can be used with switches, or light dependent resistors...Tested.

Because the 18M2 initialises all pins to input, none of the circuitry on the board has any access to the 18M2 and effectively does not exist until the program defines a pin as output or reads an input pin.

For those prepared to cut the lead of a resistor, 2 of those pins on the input socket can connect to an ADC.

Dave

Photos, board layout and datasheet on the earlier thread.
http://www.picaxeforum.co.uk/showthread.php?t=18372

 

[Rbeckett]

Great idea Dave. How well did the ADC work? I am woring on a stepper motor device that could use the amperage. Thanks for your input, it gives me more ideas to help build my device and make it work properly.
Bob

 

[WHITEKNUCKLES]

Bob,

I used 2 ADCs and both worked as normal, the pull-up resistors had been removed to give direct access to the pins of the 18M2.

The 4 pull-up resistor on the bottom edge of the board are numbered from the left and the pins of the input socket are connected as follows reading downwards.

+5v .......for the logic
Ground (commoned)
B.3 to R3
B.2 to R2
B.1 to R1
B.0 to R4..... Only B.0 has no ADC option.

For the "number" of steps ADC, I removed R2 and used an external 10k pot on B.2.
As small size was required I fitted the 10k preset on the pads that had held the pull-up for B.7 otherwise I would have used one of the spare input pins as I had for B.2.

I would add that there was no problem cutting the track to free the "Enable" pins 6 and 11 on the underside to allow PWM to be connected from B.6 or B.3 input after removing the pull-up.
If I can help?

Dave