Motor Shield V2.3 v=12?

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scotch1
 
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Motor Shield V2.3 v=12?

Post by scotch1 »

Would like to power this https://www.amazon.com/Waterproof-Digit ... way&sr=8-8 using the shield by:
1. USB to the Arduino to send data
2. REMOVE the jumper (black plastic thingy)
3. Input the correct voltage into the 2 power in sockets.

Q:
A. the motor operates better at 6.8V: DO i have to use that exact value, or can I use a 9V or 12 V direct to shield?
B. Using a 9v or 12V to the arduino with the black jumper will limit the voltage to shield to 5V: Will is also limit it to 5v ifthe USB is also being used and the 9V or 12V into Arduino with jumper?
:)

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adafruit_support_bill
 
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Re: Motor Shield V2.3 v=12?

Post by adafruit_support_bill »

2. REMOVE the jumper (black plastic thingy)
3. Input the correct voltage into the 2 power in sockets.
No. Using the motor shield, servo power is not affected by the VIN jumper. If you want to use an external source, you need to cut the trace and feed power to the optional servo power terminals as described in the guide: https://learn.adafruit.com/adafruit-mot ... servos-8-2
A. the motor operates better at 6.8V: DO i have to use that exact value, or can I use a 9V or 12 V direct to shield?
According to the documentation, that servo is rated for 3.8v-6.8v. Using a higher voltage may work, but the servo will run hot and its operating lifetime will be shortened.
B. Using a 9v or 12V to the arduino with the black jumper will limit the voltage to shield to 5V: Will is also limit it to 5v ifthe USB is also being used and the 9V or 12V into Arduino with jumper?
As mentioned above, the VIN jumper has nothing to do with power to the servos. To power the servos separately from the Arduino, you need to cut the trace on the bottom of the shield and feed power to the optional servo power terminals.

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scotch1
 
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Re: Motor Shield V2.3 v=12?

Post by scotch1 »

Not clear on:
cut the 5v trace on the bottom of the board and connect a 5V or 6V DC supply directly to the Opt Servo power input.
Does that mean to take an exacto knife and saw thru the PCB line running 90 deg to the arrow on the underside?
If done, does that mean I can't power the servo from USB or barrel jack to Arduino anymore: Must rely on external to the terminals on shield?

Also, ran a sketch with the same servo plugged into arduino UNO, no prob. Then plugged the three sockets into the shield on arduino and it ran for 10 seconds, then unplugged or stopped: the front end I am using to send info to the arduino indicated buffer full, check com port, and looks like it disconnected. Doesn't do that without the shield.

Any clue what could be happening?

Input is to com port 8, Baud rate 115200, stop bits 1, data bits 8, parity None, no flow control.

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Re: Motor Shield V2.3 v=12?

Post by adafruit_support_bill »

Does that mean to take an exacto knife and saw thru the PCB line running 90 deg to the arrow on the underside?
Yes.
If done, does that mean I can't power the servo from USB or barrel jack to Arduino anymore: Must rely on external to the terminals on shield?
Yes.
. . . Doesn't do that without the shield. Any clue what could be happening?
If you are still using power from the UNO for the servo, there is no difference between running a servo direct or via the shield. The servo headers on the shield are a direct pass-through of pins 9 and 10.

The specs for your servo claim a stall torque of 21 kg/cm at 5v. That translates to a stall current of around 2A. So even normal servo movement will likely have spikes well above 500mA which will wreak havoc with your Arduino 5v rail.

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