Which pins are actually needed for 'Motor Shield Rev3'

Projects General Guidance
1

I have a Uno R4 WiFi and want to connect it to a 'Motor Shield Rev3', but I don't want to mount it on top for two reasons:

  1. I don't need the Brake and Direction pins. I can fix them Low on the shield and use the corresponding pins on the Arduino for other things
  2. It hides the LED Matrix on the R4

How do I know which pins I need to connect between the Uno and the shield?
Is there a doc for the shield that tells me?

Here's what I know for my project:
A0&A1 return the current usage for my motors
A2-A5 unused?
Vin/GND/5V/3.3V I can connect up
RESET - Could I connnect this to an unused digital input on the Arduino (not RESET) and make it so the shield reset does a different function in the code, say stop the motors, but not reset the board?
IOREF and the blank pin next to it, are they needed by the shield?
0-1 TX&RX are these needed by the shield?
2 unused
3 My Left PWM
4-7 unused
8&9 Brakes I can set low on the shield for always off
10 I'm using for a Servo
11 Right PWM
12&13 Direction I can set low on the shield, no change of direction
GND I can connect up
AREF, SDA & SCL are these needed?

That all looks quite complicated, so maybe I won't do it, but could/should it be done?

2

You can look at the schematic.
You can look at examples to see which pins are used to control the drivers.

If you don't need brake and direction, you can make your life easier by building something as described in Gammon Forum : Electronics : Microprocessors : Driving motors, lights, etc. from an Arduino output pin. You can build it on e.g. Proto Shield Rev3 (Uno Size) — Arduino Official Store

Note:
Note familiar with the Uno WiFi R4.

3

Do some search here! The pinout for that board has been presented here more then once by helpers. My Pc crashed yesterday so I can't present the picture using the tablett.
Don't know UNO R4 but on UNO R3 A4 and A5 are used as SCL, SDA. On R4, I don't know.

4

I did look at the schematic: Shield_Motor-REV3c.sch (arduino.cc)
but it has pins like LSP1-4 and UMDT which don't obviously relate to anything named on the shield

5

This link explains some of it well: Arduino Uno Pins - A Complete Practical Guide - The Robotics Back-End (roboticsbackend.com)

6

There is a picture of the V3 shield similar to the UNO picture. No Pc yet here...

7

The LSP1-4 pins are the driver outputs connectors. LSP5-6 is the power connector for the L298 and the motors. With UMDT you probably mean VMOT which would be the 12V supply voltage.

The Vin is connected to the VMOT and can be used to power the Arduino microcontroller board. If you don't want that, cut the trace.

Pins D0, D1, D2, D4 and D10 are not used by the shield; see JLOW and JHIGH headers in the schematic. D5 / D6, A2, A3 and the I2C pins are not used by the shield electronics and available on the dedicated headers.

The reset is only a convenience button because the shield will make it difficult to reach the reset button on the Arduino microcontroller board.

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Not 100% sure if I left any unnecessary connection, but with these pins connected it works for me now (also powering the arduino via the motor shield).

9

You have two profiles?

10

Unlikely as the logins appear to come from two different countries

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