Asked
Resolved by Proteus!
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
Hi Dave,
This should get you started, using only plus and negative wires. maybe Jeremie will chime in too.
https://synthiam.com/Community/Questions/Ping-Jeremie-1663
The super caps we use for the inmoov and it helped a lot. The only trouble is you have to wait a few minutes to reboot the EZB because the power takes forever to drain
. A supercap will work for you, I'm sure of it.
Hello Dave,
The best method I found for utilizing supercaps to prevent brownout was this:
Use two 2.7V rated 1F capacitors in series, which is equivalent to a 5.4V rated 0.5F cap.
Keeping in mind proper polarity connect the series of supercaps to the 3.3V rail.
While many people may encourage you to place the supercap on the Voltage input rail, the solution above allows you to use less supercaps to keep the 3.3V rail shored up to prevent brown-out. Supercaps ain't cheap so the less you can use, the better!
Thanks Jeremie for the info.
Will this fix work even though I'm pulling no amperage through the EZB? My power circuit that feeds the ezb may be sagging when many motors are turning. These motors are attached directly to the Power supply and not through the EZB.
If so I assume that the caps being attached to the 3.3 rail backfeed the needed power when the main power feed sags keeping everything stable in the EZB?
Didn't you have a tutorial or a thread on this forum showing all this?
Thanks again for the help!
Yep, it acts like a mini UPS and will hold the 3.3V power rail up for even a few seconds.
I can do a tutorial, no promises on when I can get it to you though. Got a busy weekend
No worries on the timing. II found these caps at Mouser and have them ordered.
Thanks again for the help.
I assume the cap legs are attached in series between a 3.3vdc regulated power pin and a ground pin (and in the proper polarity of course) as you mentioned?
That’s correct
first cap negative leg to EZ-B ground
first cap positive leg to second cap negative leg
second cap positive leg to EZ-B 3.3V
You can use the GND from any black pin on the EZ-B and grab the 3.3V from the Analog header red pins or the 3.3V on the UART0 header.
Your the best Jeremie!!!