Powering a camera slider etc

Other Hardware Motors, Mechanics, Power and CNC
1

I'm just in the throws of finalising my camera slider project, and a couple of queries.

I'm using an Arduino UNO for control piggy backed with an Adafruit stepper shield.

I'm intending to run 12V DC into the Arduino, then solder some wires on the back of the barrel jack and up to the 12V input of the stepper shield.

I reckon the camera slider will be used for approx one hour at a time before recharging.

The stepper draws 0.4A per phase at 12V.

This is the battery I'm considering.

May I have your comments?

Ken

2

Well, try powering the whole setup with a 12v wall wart and measuring the current. Divide the capacity of the batteries (in amp-hours) by the current draw (in amps). That will give you the approximate runtime.

3

Having just read a later post where one battery pack was used to power the Arduino, plus shield and motor, it seems this may be a no no as the gentleman was having issues.

http://forum.arduino.cc/index.php?topic=330729.0

So is it better to power the Arduino with say a 9V battery, and the motor shield plus stepper with a separate 12V battery? I appreciate that all the negative leads be tied together

What's the consensus?

Ken

4

Yes, motors will give the Arduino power supply glitches. But try not to use a 9V battery. 6x AA batteries will last a LOT longer. Power the motors separately by all means.

5

You may find a DC-DC converter to generate a lower voltage from the 12V is a good approach,
since it will handle the vaguaries of the 12V motor supply and be efficient. When you say stepper
shield, can you clarity which board you mean and which motor you have / are thinking of?

6

Hi MarkT

The stepper is a Sparkfun unit, nema 17, 200 steps. 0.4A per phase
The motor shield is an Adafruit unit
The control board is an Arduino UNO

Interesting to be advised NOT TO USE A 9V BATTERY for the Arduino, I'll take that on board

Incidently, how much power does the Arduino use?

Ken

7

A 9-volt battery gives you the worst capacity-to-price ratio. I use one for a few weeks, occasionally using it to power my 3A 5V regulator. Understandably, it dies pretty fast.

8

Start again and tell us which exact hardware you have, not a rough description - model number,
datasheet, product webpage, something definitive.