Weird behavior from Arduino Uno when using external battery as powersource

Hello guys.

I am totally new to this game, but find it very interesting.

I have made a simple "useless box" with the Arduino Uno, three servos and a SPDT switch. The problem: So all of my 10 programs works great and in the correct order when pressing the button 10 times :smiley: . BUT when powered from a external battery ( tried LIPO 11.1V or even 7.4V) only 3 of the programmed programs work - its looping only 3 of the programs... :neutral_face:

Anyone know what can cause this?

Thanks,

M

I wonder if my tx cable may be bad. Can I connect the battery directly to the Arduino? Negative/ground cable to ground pin and positive to...?.... VIN pin?

M

Just tried to connect power to VIN and that made no difference at all! Still only 3/10 moves are executed..

Anyone know might be the problem?

M

Can you provide links to the hardware you're using? Include links to the servos, batteries, voltage regulator and any other hardware.

Please post a diagram of how everything is connected. You can draw a diagram on paper and take a picture of it (use these instructions to insert images).

One obvious thing wrong with your project is you don't mention how the servos are being powered. The Arduino's regulator can't source enough current to power three servos. It's a bad idea to power even one servo from the Arduino.

Many servos don't tolerate voltages higher than 6V. I've had a few go up in smoke by trying to power them from a two cell LiPo.

You'll want to use a separate regulator for the servos. There have been a bunch of threads lately about powering multiple servos. Let us know if you need help finding these threads.

So here goes:

-Power HD Servo 1900A: (Pololu - Power HD Micro Servo HD-1900A) X2
-Power HD Servo 1600A: (Pololu - Power HD Micro Servo HD-1600A) X1

(Only 1 servo operating at all times.)

-SPDT Switch: (https://www.elfadistrelec.no/no/vippebryter-vippespak-on-on-apem-5636ab/p/13522505?q=vippe&page=5&origPos=11&origPageSize=50&simi=94.09)

-Lipo battery 7.4V 800 MAh
-Or Lipo 11.1V 1100mAh

Im using the Arduino software for programming and uploading.

The servos are connected to the 5 V pin on the arduino. Its working while connected to pc, why shouldn't it work connected to lipo?

Please provide links for multiple servos setup.

Thanks,
M

electronicmate:
Please provide links for multiple servos setup.

https://forum.arduino.cc/index.php?topic=369551.msg2547987#msg2547987

Shouldn't be any problem powering one servo with the arduino uno, it has 5v output....

electronicmate:
Anyone know what can cause this?

DuaneDegn:
It's a bad idea to power even one servo from the Arduino.

electronicmate:
Shouldn't be any problem powering one servo with the arduino uno, it has 5v output....

I think it's rather obvious the Uno does have a problem powering one servo. I doubt I'm the only one not surprised by this.