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Playback Of Several Several Servo Recorder Recordings Disconnects EZB V4
Has anyone had this issue? When I play back three recording of six servos the EZB will randomly disconnect from WIFI to my router. The EZB does not brown out or reboot. It simply disconnects. There are also other scripts running at the same time moving other servos and sound file playback on the robot.
There's my setup and what I did:
- I have three servos in each arm in my robot for a total of 6.
- I'm using EZ Robot's HDD servos.
- One servo moves a wrist, Second one opens and closes a claw and the third rotates the claw about 180 back and forth.
- I used the servo Pad to move them and used the servo Recorder to record them.
- I now have three recordings. One recording is of left arm moving the wrist and rotating the claw, second recording is the same but of the right arm, third is of both claws (right and left) opening and closing.
- The servos in the recordings are moving very fast.
- The recordings are playing back at the speed of 1.0 (normal speed)
Here's how I solved the issue. The EZB does not disconnect anymore:
- I reduced the playback speed to 0.6. *I haven't tested raising the playback speed yet to see at what point I'll start getting disconnects again. It's a random problem and I don't want to spend hours finding that line. I'm ok with the speed of 0.6 for now but would like a more frantic look.
My Question: Why am I getting WIFI disconnects at full playback speed? Am I flooding the WIFI digital pipeline?
Related Hardware EZ-B v4
Related Control
Servo Recorder
@Jermie or other knowable builders,
I have built and connected the supercaps as you laid out above. It seemed to attach to the 3.3v rail without issue. I really hadn't tested it under servo load though. Today I have a problem pop up related to this setup.
With the caps installed on the EZB Analog header (Neg caps lead to black ground pin and Pos caps lead attached to the 3.3v power pin), the EZB seems to lock up and will not connect to my network. I'll hear no voice prompt. I will have a green flashing LED and also a steady red LED. With the caps removed from the 3.3v analog header the EZB boots properly and attaches to my WIFI network properly with a voice prompt saying "I have successfully connected to your network". I then get a steady green LED and a steady Blue LED.
One odd thing did happened as I was troubleshooting this issue. With the caps attached and after several attempts to reboot the EZB by power cycling, there was one time it succeeded in booting up and attaching to my WIFI network. However when the voice said "I have successfully connected to your network", she was speaking very fast and the tone was very tinny. She sounded much like Alvin The Chipmunk. When I connected to ARC everything seemed to be working properly. Then, the next reboot (with caps installed) I was back to lockup with no voice prompt.
I haven't changed anything on the robot that I can think of since I installed the Supercaps and the EZB would properly boot and attached to WIFI up until this issue started. I did take apart and then reassemble him but nothing was changed with the control or power systems. Just plugs and bolts taken apart and reattached.
Odd I had a week of proper bootup and connections then today this starts. Does anyone have any ideas what's going on?
I also sent a support question to EZ-Robot about this problem.
Another day another surprise. I was moving the supercars from the analog pins to the 3.3v pin of uart 0 and a few seconds after I was done the fuse blew on the power feed to the ezb. As soon as I replace the fuse I noticed a burning smell and saw the magic smoke curling out of the ezb. Ugh! Don't know what I did but "It's dead Jim". Any idea what that little chip with the hole in it does in the above pic?I have several other ezb's so I'm in process of switching out. One other question. I noticed the old bottom board that just burnt up has a big flat yellow antenna on it. The label on it says ez-b v4. The newer ezb's bottom board I'm switching to does not have an antenna on the lower board and looks totally different. Obviously this is the newer version. I thought the in performance enhancement of version 2 was in the upper board. Does the lower board give a performance enhancement also?
Hello Dave,
I'm not quite sure what's going on but here are the things I can tell you:
The big yellow antenna that you are referring to is a resettable thermal fuse. We found that the thermal fuse didn't really offer much more protection so we removed it from the design when we updated the lower board.
The chip that has the hole in it is the switching power supply chip.
Try not to move a fully charged super-capacitor (or any capacitor for that matter) onto a PCB as there will likely be an ARC that can damage the electronics, safely discharge a cap with a power resistor, or lightbulb before moving it.
One other thing to note when using a super cap on the 3.3V rail. When resetting the EZ-B you need to wait a while when shutting down as the cap will reverse power the EZ-B until it fully discharges. Turning the EZ-B on and off really quickly with the super cap installed will have very weird results as you'll have the super cap providing low voltage and the SWPS providing 3.3V to the circuit and the Microcontrollers are likely still in a brownout protection state. You need to wait a minute after removing power for the super cap to completely discharge and be ready for power again.
Thanks for taking the time to explain this. I have no doubt that I am the one who blew that chip up. Just kind of wanted to know how I did it. Lol. It all makes sense now.
I installed another tested and known working EZB V4/2. Everything is up and running again.
However the new EZB still locks up when the Supercaps are added. I did not turn the power on and off this time. Just one power on to test boot and connection with the old Cap bank added.
I wonder if one or both caps are damaged. I don't have a capacitor tester to find out. I'll make up another cap bank with a new set of caps tomorrow and try again.
Hmmm, I’ve never experienced lock up when using a supercap. Could you post a picture of your supercaps?
Electrolytic capacitors are fairly hard to damage, unless you connect them in reverse, then they usually go boom
Thanks for the interest Jeremie. I'll attach a couple pics of what I made up and was using. I noticed that the two legs that I have tied together are very close to their side walls. I wonder if they were shoring out? I did have them in a shrink tube that I cut off for these pictures. But thinking it through I don't think it would mater if the caps shell got energized in this setup.