I’ve been working on this bot on and off between deployments and it’s almost finished.
To sum up my problem when I press start on the PS2 controller the femur and the tibia on all six legs snap to the 180 degree position instead of the default position. I had no issues updating the firmware (2.07EGP) on the ssc-32 or aligning the servos. Also, I programmed the BAP 28 with an unedited version of apod_ps2.prj. For power I have a 9v battery for the logic and twin 7.4v batteries for the servos. Any ideas where I went wrong?
I’ll post pictures whenever the forum will let me.
7.4v batteries for the 6v servos!! are you using a regulator? if not you may be pumping to much voltage and you are damaging the servos…
If they have all moved to 180º my guess is that something went wrong in the initial setup.
Were the servos centred when you assembled it?
If so, a work around would be to release some of the screws and move the brackets to the position they should be in then just reattach. better to do this while it powered so you dont rotate to horns while making these adjustments.
At first I thought I made a mistake aligning the servos, so I reset them so that the robot stood correctly. The problem with doing that was when I tried out the walking gait it couldn’t lift its legs!!! The servos are trying to push against their lateral limits. I ruled out the batteries effecting the servos right away because its only the femur and tibia on the legs that are acting weird.
Again hard to know exactly what all is going on. From the pictures, I could not tell if all of the servos are HS-755HB 1/4 scale servos. But the spec for these show voltage range of 4.8-6v.
Software wise, it could also be that some/all of the legs are reversed from the Lynxmotion A-Pod. That is, with the Lynxmotion robots, there are 3(or here maybe 4) left legs and 3(4) right legs. As the legs are different there is code that reverses the direction of the servos. It has been a long time since I played with some of the Phoenix code on Basic Atom Pros, and I don’t have an A-pod, so never worked on this exact version, but if this is the issue, you may have to play with the code in the function GetPWMValues [LegIndex]
which is in the Phoenix_Core.bas file. You will see something like checking if the legs are in the range 0-2 do one thing, else do something else. This is where it handles the differences in directions of the servos.
Kurt
P.S - Will be fun to see it move. I am guessing it is pretty heavy!
I took your advice kurte. I reversed the direction of the femur and the tibia. Took awhile to find because it was all the way at the bottom of the core file.
This is what happens when I press start on the controller.
As you can see the legs retract to the body. When I push forward on the joystick to make it walk the coxa moves as it is supposed to; however, the femur and the tibia remain tight against the body like in the picture.
If there is any more information or pictures I need to add please let me know. I’m dying to get this thing walking.
From your picture, not sure if anything is wrong or not… When you press the start button, it should go to the home position, which in most cases is with the robot legs set such that the body just hits the ground. You can then use the correct buttons on the PS2 to raise the body. As I have said I don’t have one of these so have not played with the PS2 control of it, but if like most of the hexapods, hitting the Triangle button on the PS2 should raise the body up (Or if up, put it back down), like wise the D-Pad (4 direction button on left side) Up should raise it some, like wise the D-Pad down should lower it some…
Also unless your A-Pod has the same dimensions and the like of the real A-Pod, you may need to update the dimensions, ranges, default position… of the different servos and the like in the file phoenix_config_3dofapod.bas.
When you added the servos, did you calibrate them correctly, and also check to see their orientation with respect the the original A-Pod (i.e. are all the servos set up the same way?)
It looks like it would be a fairly heavy robot ; are you certain the servos can actually lift it?
