Usable Arduino pins for Motor Shield Projects

[ril3y]

Limor wanted a sticky in the forum so here it goes:

What pins can be used for external components on the Arduino with Ladyada's Motor Sheild?

Answer:

What pins are not used on the motor shield?
All 6 analog input pins are available. They can also be used as digital pins (pins #14 thru 19)

Digital pin 2, and 13 are not used.

Digital pin 11: DC Motor #1 / Stepper #1 (activation/speed control)
Digital pin 3: DC Motor #2 / Stepper #1 (activation/speed control)
Digital pin 5: DC Motor #3 / Stepper #2 (activation/speed control)
Digital pin 6: DC Motor #4 / Stepper #2 (activation/speed control)
These pins are in use only if the DC/Stepper noted is in use

Digital pin 4, 7, 8 and 12 are used to drive DC motors and Stepper motors via the 74HC595 serial-to-parallel latch
All these pins are in use if any DC motors or steppers are used

Digitals pin 9: Servo #1 control
Digital pin 10: Servo #2 control
These pins are used only if that particular servo is in use

------------------------------------------------
AND
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How can I connect to the unused pins?


The analog pins (analog 0-5 also known as digital pins 14-19) are broken out in the bottom right corner.

Pin 2 has a small breakout since its the only truly unused pin

The remaining pins are not broken out because they could be used by the motor shield. If you are sure that you are not using those pins then you can connect to them by using stacking headers when assembling the kit or soldering onto the top of the header with wires

[adafruit]

w0ah! someone helping out? thanks!

[jwm20]

In regard to using the stacking headers on the motor shield, I think I'd like to assemble the motor shield I ordered a couple days ago with them, but I'm not exactly sure what the best method for assembly would be. In the online instructions at http://www.ladyada.net/make/mshield/solder.html the headers are inserted in the Arduino for alignment, and soldered from the top of the PCB. If the female stackable headers are used, I am thinking that the header itself will block the top contact, and if they're soldered from the bottom, then they couldn't be aligned perfectly in the Arduino. Without having the parts in my hands, I can't tell just how much of a problem this might be, but if anyone has suggestions for this part of the assembly I'd be happy to hear. Thanks a lot!!

[Len17]

Here's what I did:

• Use tape to hold the header piece in place.
• Try to get it as straight as possible, then solder just one pin. Solder on the bottom of the board.
• Check if the header is straight and flush. If it's not, re-heat the solder and nudge it.
• When it looks right, solder the rest of the pins.

Looking at my motor shield, the header strips are almost but not quite in line. Close enough to fit on the Arduino.

[mmmalmberg]

What about the RX & TX lines? They appear to be unused on the motor shield, correct?

[adafruit]

they are not used. (if they were, you woudlnt be able to upload new code!)

[mmmalmberg]

Thanks. I need to use the motor shield along with a ZigBee shield, which already requires moving a jumper to upload, for that reason.

[08havoc]

Are there any diagrams with this on it?

[adafruit_support_bill]

There is the schematic:http://www.ladyada.net/images/mshield/mshieldv1-schem.png

[whiskey]

another good option/attachment would be the screw shield.

http://www.adafruit.com/index.php?main_ ... cts_id=196

[Navntoft]

Digitals pin 9: Servo #1 control
Digital pin 10: Servo #2 control
These pins are used only if that particular servo is in use

Pins are swapped at the shield.
Digital 9 to servo #2
Digital 10 to servo #1

[nootrope]

Digitals pin 9: Servo #1 control
Digital pin 10: Servo #2 control
These pins are used only if that particular servo is in use

Pins are swapped at the shield.
Digital 9 to servo #2
Digital 10 to servo #1

Navntoft is correct and this item still hasn't been corrected in the Motor Shield FAQs http://www.ladyada.net/make/mshield/faq.html. The Motor Shield port labeled SER1 is connected to pin 10 in the Arduino and the one labeled SERVO_2 is connected to pin 9.

Thank you!

[Slugsie]

I've just assembled my Motor Shield, and I cna't wait to start using it, pity that I'm still waiting on the stepper motors to arrive.

In regard to using the stacking headers on the motor shield, I think I'd like to assemble the motor shield I ordered a couple days ago with them, but I'm not exactly sure what the best method for assembly would be. In the online instructions at http://www.ladyada.net/make/mshield/solder.html the headers are inserted in the Arduino for alignment, and soldered from the top of the PCB. If the female stackable headers are used, I am thinking that the header itself will block the top contact, and if they're soldered from the bottom, then they couldn't be aligned perfectly in the Arduino. Without having the parts in my hands, I can't tell just how much of a problem this might be, but if anyone has suggestions for this part of the assembly I'd be happy to hear. Thanks a lot!!

Just thought I'd pop in a suggestion here that I'm surprised no-one else has made. If you have another shield - any one will do - pop the stacking headers onto the underside of that, poke them through the motor shield, and then solder them into place on the motor shield from the bottom.

[stevegalaxy]

Hi, new to this forum.. and electronics in general so sorry if a stupid question.. but was wanting to add a LCD shield like the D-Robotics one

http://www.yerobot.com/shop/arduino/ard ... hield.html

..to this motor shield.. it needs 7 digital pins and 1 Analog.. will I have enough spare pins for this?

and can I change pin order for either the lcd shield or this motor shield.

The LCD shield uses LCD4bit library.. so I guess I somehow change the pin order in this?

Thanks

Steve

[adafruit_support_bill]

The pins available will depend on which motor channels and/or servos are in use. See the first post in this thread for detail.
Also, check out the LCD I2C/SPI backpack. It lets you drive many LCD displays using only 2-3 pins.