Arduino disconnects when using firefly with a Servo

Hi,

I am doing the firefly's primer and I get a problem with my servo and firefly. When I try to send a value to the component ''Uno Write'' with the number slider the arduino board automatically gets disconnected. It's then impossible to control the servo.

Did anybody encounter this kind of problem?

My DPin9 is set to Servo

My hardware configuration is exactly the same as the one on the page 20 of the primer.

I have Grasshopper Build 0.9.0056

Firefly 1.0067

Rhino 5 rc3

Arduino Uno RC3

Servo model = MG995

I attached a picture of the grasshopper definition with everything useless removed (it shows what happen once I try to send a value to the servo) and a picture of the hardware setup

Attachments:

hardware.jpg, 784 KB
picture.png, 176 KB

Replies to This Discussion

Permalink Reply by Andy Payne on May 28, 2013 at 8:28pm

My assumption here is that your servo is drawing more current that your Arduino can provide, and thus crashing your Arduino (and the serial connection is severed). I tried to find the datasheet for the servo you listed (is it the TowerPro MG995?) If so, this particular servo does look like it has quite a bit of torque (around 135 oz./in) which leads me to believe it's also drawing a lot of current... although I couldn't confirm with an actual datasheet. Do you have any other servos lying around which might draw less current you could test with? Alternatively, you could connect an external power supply (something like this should work: https://www.sparkfun.com/products/11456) so that your servo is only drawing power from an external source and not directly from your Arduino. The 5V output power pin on your Arduino can only supply about 500mA of current.. so if you're servo is drawing more than this, then it will likely crash your board. The external power supply I suggested has a rating of 1A (but you can find ones with more current if you need it). The one key when connecting an external power supply is that you also want to make sure the ground of the Arduino is connected to the ground pin on the external power supply. As long as all the grounds are connected, you should be fine. Anyway, your GH definition looks correct, so I think this is a hardware issue.

HTH,

Andy

PS, this discussion might be better placed under the Firefly group page :)

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