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
Conclusions so far to this point: #When the AXV super caps get down to near T=0 they are seen by the EZB as a dead short and shuts down part of the board, disconnecting it from my network. #When the AXV caps are charged and disconnected from the EZB , the next day when I boot the EZB and connect I'll then close in the charged caps and everything remains stable. #It seems that the EZB drains the caps when all external power is turned off. Perhaps the cap drain happens because the EZB is still trying to draw power to operate.
Questions still unanswered; #Will the new Series B caps I have yet to use to replace the current AVX caps have this same behavior? New caps coming: Supercapacitors / Ultracapacitors PowerStor / Eaton 1F 2.5V EDLC B SERIES CYL. These have a much lower ESR () (Equivalent Series Resistance) then the AXV caps. #If the PowerStor / Eaton caps do seem to work for this application do I still need the relay to disconnect them from the EZB when external power is disconnected? #If I still need to disconnect with the relay due to drainage then why is the EZB draining power and why are other builders having success with this modification and I am not?
Thanks again Jeremie for keeping me in line and helping me to understand.
The only way I've been able to get the AXV supercaps to work with the Super caps I currently have is with the relay. I'll get the new caps tomorrow and swap them out and pull the relay out of the circuit.
I read in the supercaps data sheet that these caps are very sensitive to soldering heat. They recommend soldering quickly to keep from damaging the caps. I'll be careful not to apply too much heat when soldering the legs together.
Your recommended removing the "other item" I have on the ADC header. I'll do that if needed but it's only an open switch. I don't even have a pull up resistor on it.
Good luck with your new supercaps Dave. I personally would leave the cap legs a little longer if you have room on the B9, IMO.
My the Robinsons be with you.
Good news. I received my new SuperCaps Thursday evening and installed them yesterday. They are wired and hooked up exactly like the first set shown above. They seem to be working properly now with no EZB lockup on powerup. Wahoo! love
I'm not really sure what the secret is that made the difference. Weather it's the ESR, whatever the "B" series is pertaining to these new caps or I damaged the other set soldering them together. My "gut" tells me that Jeremie is correct that the caps ability to take a quick charge is key.
As far as an operational test I did get one lockup and wifi disconnect while checking things out after the install. I was running all the servos in the robot at the same time, moving them back and forth quickly and repeating this test quickly many times. I think I was depleting the caps and simply drained them of power faster then they could recharge. I slowed down the servos a little and doing the same testing this never happened again. All and all I'm pretty happy with this now.
Thanks again for all the help. I'll let you know if anything changes.
Here's an update on the of original issue in this thread. This issue continued even after applying suggested solutions in this thread. Recap and final working solution: #I was having trouble with the EZB disconnecting from the WIFI network and needing to be rebooted before it would work again. This happened when servos moved in a very quick moving animation routine that I had recorded using the servo Recorder and servo Pad. #Servos used are 6 EZ-Robot HD servos. They are all moving at the same time. #This animation and others created by the servo Recorder using the servo Pad was being played back through an EZ script in ARC when the shutdown happens. There were three separate servo recordings being played back in that script involving the six EZ-Robot HD servos. #I was advised to attach super caps to the 3.3 ADC power rail to shore up and stabilize any voltage sag caused by the servos drawing peek power when they moved. #After installing and overcoming an issue with the Super caps not allowing the EZB to fully boot, the original issue of random EZB WIFI disconnection continued. #Conclusion: The Super caps did not fix my issue in my case. After much testing to try to nail down when exactly this happened I have come to believe that my issue surrounds the way I recorded the servo movements. By me recording very fast and erratic servo movements using the servo Recorder using the servo Pad I believe I was overdriving the servos and the quick back and forth of the DC motors may have caused voltage spicks to feed back to the EZB controller thus causing some of it's components to shut down. #Proof: I have other animations using the same HD servos created by the Servo Recorder using the servo Pad that have slower, more fluid servo movements. I have never experienced any shutdown issues when playing back these recordings through ARC using EZ scripts. #Solution: I removed the Supercaps and I scraped the three recordings that were causing the shutdown issue. I then used the AutoPosition control in ARC to recreate the wanted animation of the six HD EZ-Robot servo movements. In the EZ Script that I was using I removed the commands to playback the three servo recordings and replaced them with the new AutoPosition action command. After testing this change many times I have had zero shutdowns or issues. #Remaining questions: What really caused the shutdown? Was it the voltage spick of the DC servo motors backfeeding into the EZB? Was it simply to many Servos drawing peek power too often? Since the issue happens both with a large battery amp hour supply and a AC to DC power converter I'm going with the former. I've found a solution and am moving on.
Unless the EZB shutdown issue pops up again I'm going to say all is well now based on what I outlined above. I am a little disappointed in the results of recording servo movements with the Servo Recorder using the servo Pad in regards to causing my issues. However I don't blame ARC and it's controls. I blame the limitations of the devices I'm using and basic natural cause and effect.
I would love to hear any thoughts on this matter about any of this from you all. Thanks so much for the assistance in my efforts to resolve this. You guys rock!