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11 Servos on red back spider (ATmega1280), how to power?

Hi,

 

I'm stuck! I am trying to connect 11 servos to the red back spider board, and as soon as I turn on the power (up to 12v) the servos all jerk and move like crazy and the board turns itself off again. 

 

I'm not quite sure what I am doing wrong or how I need to power 11 servos (9g micro servos) without the board crashing? 

Anyone can help me out?

 

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Please post some photos of your setup and a wiring diagram if possible.

 here's my setup, just servos plugged into the shield, all with 5.6 or 10k resistors 

11 miniature servos as a load is not a problem. Your power supply and wiring is your problem. I want to see exactly how thick is your power wires, what batteries you are using, how you wired them up etc. I want to see the photo because I might see something you've missed. It needs to be a high resolution photo. It needs to be clear. Phone camera probably won't be good enough.

Even with the servos twitching on powerup the spider will handle 11 miniature servos easily if your power supply is good enough.

Apologies! 
I'm using this battery: http://www.sparkfun.com/products/8484

And it is currently plugged into the board directly through " insulated 0.16mm copper conductor with a 7mm long, 0.6mm diameter pin" jumper wires

Will try to get a better picture as well. 

Can now get all 11 servos to work if I plug them in one by one, this will then continue to work as long as I keep the battery plugged in, resetting the arduino or uploading new sketches doesn't seem to affect it. 

And thanks again for your help on this!

 

could you lose the two 2 pin blocks and switch and replace the whole mess with a 2 pin header and a jumper that could be removed and the control board plugged in?

The reason for the on board switch is that it used with Wild Thumper products. As you can see below, when mounted in the correct position it can be easily accessed yet it is unobtrusive and protected by the overhanging top deck.

The 2 pin headers were an afterthough to provide greater flexibility.

But, I will try to explain myself better. If you remove the headers and the switch and replace the two active pins of the switch with a 2 pin header, you could close your circuit with a jumper that connected as the switch does or run a control wire from the uC to the active pin on the pin header and save yourself a few cents. You could even connect an external switch to the header, if you were so inclined. Is it still clear as mud?

I want to reiterate that after seeing the mounting I understand the logic behind the current design.

Yes, I understand now. I will see if it can be changed.

The Spider uses a switchmode power supply. This means it needs to draw high current, pulses of power from your batteries. Not only do you need good batteries (NiMh or LiPo) but you need heavy wire and good connections in your battery holder.

Your servos will twich because when MCU's power up, all outputs are high impedance. The easiest solution is to put a 4.7K resistor in each servo plug so that it connects your servo signal pin to the ground pin.