Penguin Problems
Hi, my penguins (1 red, 1 black) arrived just before Christmas. I have just finished putting them together & I think I followed the instructions correctly, but I seem to be having some problems getting the tilt servos to work properly. Everything else is working fine, and I have centered the stride servo, but the tilt servo doesn't seem to want to turn, and it gets very hot. The same thing is happening on both penquins, so I assume I have made the same mistake on both. Any suggestions?
Comments
that of the photo. The feet have direction (a front
and back, left and right) and the long linkages
should be free to move. In fact, with Penguin off,
you can move the servo horn in both directions
freely. This is the first test.
humanoido
I think you have plugged the "hot" servo in backwards.
Ken Gracey
Parallax, Inc.
Aha - problem solved, right! Not quite. My black penquin's tilt servo was still paying no attention to commands, so I tried unplugging it & replugging it in the same way. No lunck. Then I decided to try turning the plug around & unfortunately smoke started coming out of the servo. Not good.
Now when I try to calibrate the black penguin, the stride servo still works but the tilt servo horn swings around until it is at a right angle to the ground & still doesn't work.
Is my only option to replace the servo?
www.parallax.com/Portals/0/Downloads/docs/prod/robo/27313-6PenguinDoc-v1.0.pdf
This is a color version Penguin Manual.
Now go to page 6 and look at the servo cables and note
which color faces which side, and copy it on your Penguin.
Now try calibration by doing step 2 on the same page.
humanoido
the "center servos" code and see if you can get the tilt
servo to go to center position, as instructed. If it won't
center, replace the tilt servo.
You could also remove the mechanics and check the
boards. Unplug the tilt servo and set it aside. Plug in the
remaining servo into the tilt position. Run the center
program, and verify the servo does indeed center,
and not go off to an extreme position. If it does, then
the board is bad.
humanoido
I can calibrate the servos according to the manual, but once I disconnect the robot from the PC and turn it back on, it seems that all settings that I previously saved are lost and the servos start rotating incrementally until they both hit limits. I then go back to the servo calibration program and have to press "r" many times until the servos are enabled and neutral. How do I diagnose the board to rule out a faulty controller? Anyone with similiar experience?
It looks like an old version of the Penguin code had worked its way to the new web page. It has since been fixed, so you can download version 1.1, the latest version, of the Penguin code at http://www.parallax.com/Portals/0/Downloads/docs/prod/robo/PenguinCode-v1.1.zip, This version gives more control over how the Penguin walks, but most importantly, it is easier to use and has clearer and more thorough documentation. Be sure to read the “Usage” section in “Penguin-ServoCalibration-v1.1.bpx” before running it. Also, it is best if “Penguin-CenterServos.bpx”, in the “Penguin-IOExamples” folder, is run before the stride linkage and servo horn are attached. If the servos are too far off center when the Penguin is put together, it may not have its full range of motion.
- David Carrier
**edit
I downloaded and ran the latest version of the software and although it is much better in a few ways, I still have the same problem. I ran the CenterServo program and immediately ran the calibration program. I align the feet and level the tilt servos, save settings with "s", and close the debug window. I then power off the robot and disconnect the usb cable. When I switch the power on, the servos rotate incrementally by approx. 20 degrees until they hit limits.
I'm not ruling out user error, but could this be hardware? After reading one of humanoidos post in this thread about switching the servos as a test I'm still wondering if it's the board. All tests in the downloaded package were successful. I don't expect a spoon feeding here, just a nudge in the right direction. I really hope that I stumble on a fix so I'm not left hanging all weekend, or that somebody is cruising the forums and can set me straight soon.
Thanks in advance.
Post Edited (Basics) : 1/26/2008 7:51:09 AM GMT
When you power up the Penguin after disconnecting the USB does the Penguin make the Beep before the servos start moving?
If not the program isn't running.
As an aside there is a bug in Penguin-ServoCalibration-v1.1.bpx which means Walking doesn't work properly if the tilt range is >255.
I emailed KG yesterday with the fix, Indirect is used as a byte instead of 'Word Indirect' in the first block of the DO/LOOP.
Also when printing the screen, printing stops at $555 whereas it should end at $559
David Buckley
I actually started looking at the code last night in an attempt to find something out of place. And I believe that I do not hear any beeping at startup after calibrating, saving, disconnecting and powering off. But I will check in an hour or two after I make the repair to the code.
Although I understand that this forum is not holding it's collective breath in anticipation, I will post results. More likely I will just post more insipid questions.
I appreciate the help from you fine folks.
Joel
I've got a 3 year old going berzerk waiting for me to take the robot down from the bookshelf and make it do something cool. I'll admit that I'd like to get this thing working for me too.
nor the EEPROM values stored
in
Penguin-AutonomousNavigation-v1.1.bpx
in the section
-[noparse][[/noparse] Memory initialization ]-
Penguin beeps
FREQOUT Speaker, 300, 784
before any servos are driven
If you don't hear the beep the program isn't running, or the code has been altered or the beeper doesn't work or you have a different program loaded
run Penguin-SpeakerTest.bpx
does the Beeper sound?
is
FREQOUT Speaker, 300, 784
in
Penguin-AutonomousNavigation-v1.1.bpx
?
1 disconnect the servos
2 reload the program
3 does the beeper sound?
4 if yes beeper sounds then turn off, connect one servo, turn on, - does beeper sound
5 if no then get new batteries, goto 4
If the servos move before the Beep, it has nothing to do with the program, it is what servos do when they powerup and get confused, often by low voltage (the batteries may give an ok voltage on no load).
David