Svp-324p buzzer broken? (+ questions)

There seems to be something wrong with the buzzer on my board:
Running demo program resulted in the red LED blinking and the buzzer continuously clicking (probably resetting), with nothing showing up on the LCD. When I commented out everything that has to do with the buzzer everything else worked fine.
Running buzzer2, middle button seems to work fine (playing C major) but either top or bottom buttons just make the buzzer click once and reset…

Other questions:

  • It seems to be taking a long time to upload programs (7 seconds for the 4k buzzer2 + another 4.5s verifying), is that normal?
  • Is there a way to tell what Vadj is other than simply measuring?
  • What would be the best way to have a separate, >3A power supply for the servos?

Thanks!

Ok, strangely enough now I’m powering off of external power instead of USBtinyISP and the buzzer works fine. Not enough power?

Now that that problem’s (sort of) solved, the rest still stands - especially the high current servo power supply (ideally 7A).

Hello, szx.

Is there some reason you are using a USBtinyISP instead of the built-in programmer on the SVP?

Powering the Orangutan SVP from USB is not ideal. Also, if the USBtinyISP is trying to power the Orangutan SVP through its 6-bin ISP cable, that could cause a short. I recommend that you figure out how to disable that feature of the USBtinyISP or start programming the SVP through the built-in programmer instead of the USBtinyISP.

Using the SVP’s built-in programmer will probably improve the upload speed a lot because the built-in programmer is already configured to use a high ISP frequency. If you want to keep using the USBTinyISP there is probably a way to increase the ISP frequency to make programming faster.

Unfortunately, no. You could, of course, connect it to one of the free analog inputs via a voltage divider and program the SVP to display VADJ in millivolts, but if you have a multimeter and won’t be frequently changing VADJ then that it is probably more trouble than it is worth.

The “best way” depends on your application and the current consumption of the servos. I recommend getting a power supply that provides the right voltage for your servos (usually 5 V is good) and can deliver all the current that the servos will try to draw. Then I would wire that power supply to the Orangutan SVP using the appropriate pins. The SVP allows you to power servos 0-3 off of a different power supply from servos 4-7 if you want to. The Orangutan SVP Reference Diagram shows all the power connections on the board, including the 2x1 connection for servo power in the upper left:
pololu.com/file/0J244/orangu … iagram.pdf

–David

I’d love to use the built-in programmer, but I’m on OS X.

Yeah, ideally I’d like to have a single 7A @ 6V power supply powering both servo banks. So I should basically take out the servo power jumpers, and wire my power supply to the 2x1 connections for both banks?

Yes, that will work, as long as you also install one jumper to connect the power rails of the two banks together.

–David