Can I safely measure battery voltage on Arduino A0 while using CNC Shield V3.00 (A0 = ABORT)?

Other Hardware Motors, Mechanics, Power and CNC
1

Hi everyone,

I’m working on a custom Arduino Uno + CNC Shield V3.00 (red Protoneer-style clone) project (not running GRBL — custom code only).
The setup uses 4× DRV8825 drivers and 4× NEMA-17 steppers, powered by a 14.8 V Li-ion battery.
I’d like to monitor the battery voltage using a simple divider (10 kΩ / 3 kΩ) and analogRead(A0).

  1. Can i use the abort pin for a0 battery read
  2. If A0 is unsafe, are A4/A5 free for analog measurement on this board?

I only need to read the battery voltage through a resistor divider, nothing else.
I want to avoid cutting the board unless it’s really necessary.

This is part of a school project building a forklift

Thanks in advance!

— Jan

2

Please post a link to the internal schematic of the shield.

3

Quick look at V3 board indicates that A4/A5 are free.

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4

Looking at the schematic it appears A4 and A5 are free for your use. If you equated A0 as your measuring pin you can change that to A4 or A5 whatever you connect to.

I am assuming since you did not post a complete schematic A4 and A5 are open. They are also connected to the I2C pins on some boards. The default I2C pins for Arduino Uno are A4 (SDA) and A5 (SCL).

5

Thank you all for your answers i think i will just bent a wire and stick it in a4 or a5.

This is kinda the problem because i am not completely sure witch one i have but i think its this one CNC shiled

I would also like to know if the uno is also powered over the CNC shield, if someone know ?