I'm curious about NiMH battery warnings from the EZ-B. As I'm using an NiMH battery pack to power a v4, I have the LiPo battery warning disabled from within the "Connection" control in ARC. I have never had my 7.2 NiMH run so low as to disconnect my EZ-B's connection and today it happened for the first time.
When the v4 disconnected from ARC, I thought this was due to a signal dropout. I power cycled the v4 and tried to re-establish the connection only to be greeted with the verbal "My battery is low" message. So does the EZ-B have a secondary battery warning system then, or have I missed something other than disabling the LiPo battery warning in the connection control?
I know a v4 shouldn't be powered with anything under 4.5 volts and didn't get the chance to see what the voltage was on my 7.2v NiMH before the v4 disconnected. Sorry if it sounds like a daft question, but this is the first time I have come across this and was curious.
Cheers.
@Dave.
Nice post and very interesting indeed. I don't mind the warning voice too much, although like you say, it does nag a bit, but briefly on a different subject, I wish there was an option to swap it between male or female, especially on the "I am now connected to your network" phrase.
Back on topic again, and I will write a simple battery monitor script for above the 4.5v threshold for the 7.2v v4 battery (about 6v for a 6 cell battery) which will use my bots voice, but with the info that Richard gave, I want to now find a way to monitor the 12v drive battery via the EZ-B and write a similar monitor script like for the 7.2v. I know you use a mains supply to power your EZ-B, but do you, or anyone else for that matter, have any ideas on how I could accomplish this, or suggestions any magical devices I could buy that will monitor the battery voltage and send th info to an EZ-B?
What I would like to see as far as the battery low warning is concerned is to be able to run the unit for a few more seconds after that. That gives time to move the robot (JD in my case, officially named Skippy now) to a position to make plugging in the charger easier. I my case I make Skippy lower his right arm and raise his left up to his head to fully expose the charging plugin. He also straightens up to make him more stable after being turned off. This as opposed to being in whatever pose he is in at low battery time.
Right now I just have a script running which monitors the battery voltage and has it go into the "Charging Position" when the voltage gets below 6.8V. Even then it doesn't do that unless it gets 3 readings in a row at that level. I have found it can suddenly drop to a very low level on a reading of the battery voltage now and then. Also note I said "in a row." Not 3 low readings over the entire time he is running. But that, of course, leaves a bit of running time unused so it would be nicer if it would simply run for a bit even after the low battery warning comes on and disables the robot entirely.
I also have a voice command that I use to get him into position on demand. Which is, of course, also selectable from the Autopositioner window. Oh, and this is for DJ ... You'll be pleased to know I use the Autopositioner nowadays ... a lot!
@WBS00001, you can set warning to start nagging you at any voltage above 6.6 volts. If you want more time you can set the level above that minimum and that should give you the time you need. Click on the little gear in the upper right corner of the connection control then click on the Settings tab in the upper left corner of that window. Set your levels in the Min Voltage box of the battery monitor setting section. You can set this value next to each connection of the ezb you want to watch and be warned about.
Anyone have any ideas on how to have an EZ-B monitor battery voltage from a battery not powering that EZ-B?
Through an ADC port, using a voltage divider as needed to get the voltage low enough for the ADC to read. @Rich has a thread on it somewhere with instructions.
Alan
@Alan.
Excellent. thats great. I'll have a look through Rich's threads and have a look.
Thank you.
@Dave Schulpius Thank you for your post. Perhaps I don't understand the whole point of what you are suggesting, or I didn't explain myself well enough. To me, if I set the warning to a higher level than 6.6V all that will do is suddenly disable the robot sooner than it does now.
OTOH, if I set the nag warning to a voltage lower than 6.6V, then I would get the extra run time before complete shutdown I was after, but I get a message saying doing so could seriously damage the battery, so I'm Leary of that. Additionally, I would still have to run my own script to detect the voltage early so I can place the robot in the Charge Position before the nag warning comes on since the robot is completely disabled and the servos released at that point regardless of anything else.
Overall, to me, this sudden total disabling of the robot isn't too good. I've had it fall off my desk when the servos were suddenly released like that (in whatever position it was last situated). Seems to me it would be good if it executed a user selectable script before it totally disables everything. That way it can get the robot to a known, safe position first. Doing so would eliminate the need for a script like mine running all the time.
@WBS.
Running your own script to monitor battery voltage is essentially the the same thing as what ARCs monitor does, so disabling the ARC one and running your own script to check every second or so would pretty much be same thing, but with the added bonus of writing in your own more graceful "shut down" position for your robot before the EZ-B resets. But I do agree with you that if ARCs battery monitor had an optional script field to write a custom script, it would be a cleaner way of doing this and it's a nice idea. Maybe a feature request for a future update.
@Anyone else.
I had a look at the tutorial it's a good one, but not sure if it's something I could confidently do as I really don't want to risk damaging the EZ-B in any way.
I found this however which connects to the Vcc & Grd battery leads, and has a third signal wire. Would just hooking this meters signal lead to an ADC port give me a battery voltage reading?
Digital volt meter