
robotmaker
I design a circuit awhile back and sold many pcb;s with my design
My design is that you can use 4 wire instead of 5 wire to control the l298 h-bridge board,second you can control PWM seperate for each motor and add a brake if wanted
Its a 2 wire design,i dont know if it will work with EZB it should,it has one direction control and one pwm control and can be set up with total of 3 wires too
with 2 wire for direction control and one pwm control ,and if needed another wire for safety brake or overload (stall) brake.
way it set up now it uses 2 wire per motor for direction and en pin for pwm control
my circuit is under $3 in parts
You dont have to use the enable pin if you dont wont too and CD4071 ,that was for a dual circuit control.
it will have 2 pins pwm and dir ,only 2 chips is needed CD4069 (INVERTER) and CD4081 (NAND GATE)HBRIDGE.zip
This design gives 2 PWM control if needed or tie both PWM together to use 3 pins total for 2 motors ,you need 2 circuits
pwm says the same to have 2 wires and 1 pwm control for DIR for the first motor you use in pin 5 on U2 for DIR1 and for DIR 2 you use pin 9,output pins to l298 is pin 3 of U 2 to l298 pin 5 and U 2 pin 6 TO L298 PIN 7 and the same for other gate going to L298
I guess i need to fix the circuit to make it easy for others
h-bridge1.zip
pretty simple circuit ,needs 2 very low cost chips CD4069 and CD4081 it for a dual h-bridge controller
L298 or others,can be used for one motor or 2 motors or with PWM control on both motors
AND there make a few different versions of the board,one DJ sells,one i have ,pololu type and some on ebay for about $5,even sparkfun sells a different type
Mine as 4 leds 2 reds and 2 greens
The Motor controller EZ Robot sells is great for light demand motors but I fear they burn out if you use a larger motor and reverse directions quickly. It's happened to me. Another way to get around this is to build a diode board that will drain off to ground the voltage spike sent back from the DC motor when direction is reversed quickly. I built two into my robot just as added protection. I'm anal and hate to repair things that shouldn't have been broken in the first place.
if you use a diode board needs to be a very fast diode schottkey type
I DESIGN my own H-BRIDGES many times,some over 60 amps per channel
GOOD thing about my circuit you can use PWM for each channel,it helps for 4 wheel design
Also use thermal and over current protection,most h-bridges dont have it,but enable pin is whats used,
a simple current to voltage and then a comparator circuit is all thats needed