I have an Arduino Motor Shield Rev3 on an Arduino Uno. I did not find any information regarding some action to stop the Uno power being used to power the motors on the shield. My initial setup was with the PC USB powering the Uno and a 12vdc power supply attached to Vin and ground on the blue screw post with A+ A+ B+ B+ connections. A Nema 17 stepper is connected to the A & B connections. I understand that the Uno power is always used to power the logic on the Arduino Motor Shield. The sketch that I run rotates the stepper 1 revolution then waits 2 seconds. With the 12vdc power attached the motor (an Nema 17 2amp stepper that runs on 12vdc) The stepper is choppy and does not rotate a full revolution.
Here is my question: When I unplug the 12vdc power source from Motor Shield why does stepper continues to run the sketch without a 12vdc motor power source and do so correctly, revolving 1 revolution smoothly?
There is something about running two power sources that I don't quite grasp.
That only gives us only the size of the mounting plate (1.7 inch).
Which stepper motor.
The L298 is not a stepper motor driver. It's a dinosaur-age brushed DC motor driver.
It can only sort-off drive high voltage/ low current motors.
Please post a link to the motor you have.
Vin is by default connected to Vmotor, with a solder bridge that you can cut.
Leo..
Leo, thank you for your reply. Here is the stepper motor I am using:
A2Amp stepper is no match for the L298 shield.
You will even tuly release the magic smoke.
Don't get fooled by the 12volt rating of the motor, it's not true.
Leo..
You have provided valuable information. I see the two pads on the back of the Motor Shield labeled Vin connect. Are you saying I should run an exacto between the pads in order to break the connection to the motor power on the motor shield?
On a more mundate level problem, the back of the shield id covered by a thick plastic cover that I haven't quite figured out how to remove, or even if it should be.
I've removed the plastic back cover, now what do I do?
With a volt meter it shows there is a connection between the two pads labeled Vin connect.
Please tell me what happens if I break that connection? Does the Uno still provide power to the shield logic, but not the motor?
Do not use that shield for a 2Amp stepper motor.
You will burn things.
That motor needs a current controlling driver, like the DRV8825.
You can fit up to four of those motor drivers on a CNC shield, or use it stand-alone.
Leo..
Leo, you are saying I need another motor. What do you recommend for this motor shield?
This 350mA motor could be used with that shield.
Don't expect torque at higher speeds with that combo.
Your current motor and the proper driver would be a better solution.
CNC shield.
Pololu DRV8825.
Leo..
@lelapinblanc327
What is your level of knowledge of electronics and schematic and datasheet analysis?
[quote="Wawa, post:11, topic:1388559"]
DRV8825
what about the HiLetgo 2pcs 3D Printer TMC2209 Stepper Motor Drive Module Replace TMC2208 A4988 LV8729 Super Silent
with the DRV8825 I place that between the motor and the shield on the A+ A- B+ B- connections?
I hear you. the implementations of the drv8825 are direct to the Uno without a motor shield. The CNC board, you add the drv88255, right?
I was a software developer before i retired I developed a 5 axis motion control system for an animation stand with a hardware engineer in the 80's. I can read a skematic and datasheet. Not sure what analysis actually means.
Your motor coils can handle up to 2A.
The A4988 is only rated for 1Amp.
The TMC2208 is 1.4A. TMC2209 2A.
Lower current drivers is more heat and less torque.
Leo..
Leo, great information! I appreciate you taking the time to help me. So, let me ask you this: if my app only uses 1 stepper motor, can I avoid buying the CNC shield and just directly use the DRV8825?
Yes. the shield just makes connections and expandig a project a lot easier.
Make sure you set the correct motor current on the driver before connecting the motor.
Read the DRV8825 page I linked to.
Leo..