Has anyone made a wireless charger yet. use / charge / use / charge is getting a little tiresome and it is just my first week with ez-b.
Logic is JD Humanoid (or your build of choice) looks around when battery is flat finds a Glyph (that points in direction to head) and then goes to the home Glyph and parks with coil on breast plate and wireless charges. Seems to be some rough instructables to make a wireless chargers and some pseudo professional solutions
element 14 wireless
I am not sure if anyone has built something like this , logic was a script that continually does a getVoltage() and then looks around for Glyph and returns home to charge when low. EZ-B continues to monitor until each cell of the LiPo reaches optimum level and when charged heads off to play again.
Asked
— Edited
Edit:
I'm speaking of free roaming robots which tend to have larger batteries to charge.
Personally, I am waiting for 2 potential upcoming EZ-B products, the Lidar, and the navigation system using a fixed position camera so that I can solve the autonomous navigation issues first. Then I'll tackle self charging (assuming my job slows down when my current project that is taking all my time wraps up in January as I expect. I have had virtually no time for robots all year. I haven't even opened the box of HDD servos I bought months ago....).
Alan
New products? I will have to search for mentions on it.
The Lidar came up in a totally unrelated thread but DJ posted a picture of the work in progress. Can't find it now of course. Was within the past month.
There was more discussion of the fixed mount navigation camera, which I also can't seem to find (searching from the phone is tricky). This was a few months ago.
As with any of these works in progress that DJ mentions, it could be weeks or years before we see product, and some get canceled for various reasons, but it is fun to speculate.
Conversations are happening about the product launch. I'm trying to move a budget around to get the DIY components on the assembly line. It'll happen - it's just tough because Revolution is the money maker and that makes it difficult to convince the people who handle the money
Understanding that advancing the technology starts with the DIY users and products, which trickles down to revolution. Wheels are in motion... stay tuned
I had been considering putting a crowd fund together to manufacturer the diy items - but that might result in disappointing results because the diy community is so small these days
I’ve noticed that other established companies such as the UpBoard maker have successfully used crowd funding for new products
I really appreciate your support for the DIY community
Frank
I share this concern, but it would give you a good gauge of the the actual interest (or, like you did with Revolution, you could do pre-orders instead of using a crowd funding site, but then if you don't meet goal, you have to do refunds, so you are essentially carrying a liability between the pre-order and the delivery).
I think the 2 most talked about DIY things that are difficult to achieve without kludging together 3rd party stuff are autonomous navigation and action (solved with IPS and Lidar) and the subject of this thread, power docking to extend run time (requires autonomous navigation, and a lot of other work, and probably harder to retrofit into existing Revolution designs - so more strictly DIY). I think though that adding autonomous navigation and action fits so much more than DIY. It has great educational tie in. I mean, how much better is it to tell your robot to find its own way from one room to another than to do yet another line follower (I almost passed out when you did a line follower ROLI. I mean, an Arduino can do that....). Also fits into companion robots (follow me around, converse with me, pick things up for me, etc), and industrial uses (security, factory stock transport, package delivery, etc. etc. etc.).
Just my 2 cents, for what it is worth (probably about 2 cents).
Alan
That being said, I feel like we as a community are in a good place to be able to try a system similar to the Roomba docking system. You see the new Linkman charger only requires a 12V source to power it. If the Linkman charger was to be attached to an ezrobot (or DIY robot) with two connections broken out (+12V, GND) and then have a Glyph or beacon system to auto-locate the dock, one could create a automatic charging system.
A simple momentary cherry switch mounted on the robot could be used to disconnect the power to the robot once it is completely seated into the dock. Of course you would need to take it off the dock when charged or have the dock kick the robot off of itself. I guess that would make the dock a robot as well :).
Anyway, just some ideas. Although I love wireless charging it's just not all that practical for our scale at this moment in time. As mentioned though, I do think automatic charging is possible with a little creativity.
I like this approach
Thanks,
Frank
I have to agree, I think I have been watching to many iphone commercials. Why create a complex solution when a docking station would solve the problem.
I’m going to try to implement your idea.
Just to be sure, it’s ok if the version 3 changer is left connected to the battery, just as long I disconnect the 12v power. I was always under the impression that we needed to physically disconnect the charger when the battery was charged up... unplugging power to charger was not sufficient.
Thanks,
Frank
So I think a possible process could be Robot self doc's . Robot has a Magnetic switch for on off power. The magnetic switch is activated by an electric magnet on docking station so it cuts power to robot turning robot off when it identifies robot is docked correctly. Next a relay cuts in to connect power to charger, when charger detects battery is charged the same relay disconnects power to charger and then turns off electric magnet turning robot on again.
You could use a second V4 controller that is permanently connected to a power outlet to handle the smarts of the relay, magnetic switch etc. Getting the docking contacts correct and detecting when it is docked will be an interesting task as well.
I believe from my previous calculations on a fully charged battery it would take approximately 45 days for the battery to parasitically drain backward through the Linkman charger down to 6V. I'll just a test tonight and get back to you.
@Nink great idea to use reed relays and magnets! Genius!
So you need to balanced charger (3 wires) ground and 3.3v for each cell, a 3 cell battery has (4 wires) etc.
DFRobot has a 7.4V lipo with only 2 connectors
https://www.dfrobot.com/product-489.html
I asked their support and is also in the comments:
It seems allows you charge and use at same time. What ever is inside (circuit) is cool tech.
Great idea on using reed switch
I’m going to start testing this
Frank
Can you post the battery charge link ?
can you charge and use at same time ?
That is a very interesting battery
@jeremie,
Has EZ Robot evaluated this type of battery?
Thanks,
Frank
I'm guessing, the battery is the same... the difference is the charge/protection circuit and how far they went to protect/handle the charging process.
I made self charging robot and i added 2 thermistors to monitor 10 x AA NimH batteries, maybe overkill, but, i was so afraid that something could go wrong with my charger, so i added an extra circuit to monitor the temperature.
Is anyone using Li-Ions on their EZB's ?
I’m not able to find any reed switches that handle more that 0.5A
@jeremie,
What is the fuse rating inside the Revolution robots?
To be safe, I think I’ll go with the microswitch idea you first mentioned. Small ones are raated at 15A
Frank
No we haven't evaluated that battery in particular. The fuse rating in revolution robots is 20Amps.
Great idea. This is what makes the forum so great!
I’ll prototype this and let you know how it works out
Regards,
Frank
From my measurements last night my battery went from 7.558V down to 7.554V in 12hours. From these calculations it looks like the charger would parasitically drain the battery from full charge to 6V in about 300 days.
I'm sure that it would actually be less days than that but I'm pretty confident that you are ok to leaving an unpowered Linkman charger attached to the battery in your design.
Thanks for researching this
Frank
That’s a good point.
I’m pusuring this with several levels of increasing capabilities:
Level 1 would still require turning off the power switch, but would just allow setting the robot on the stand... making the power connection
Increasing levels would handle the shutting off the power switch and determining the end of the charge cycle to disconnect the power
Frank
Here is an update on my prototyping.
I thought I'd start with the manual stand approach as described by @jstarne1. The first problem is how to make a reliable easy to connect power connection.
I chose a magnetic charging/data Android phone adapter with some micro USB breakout boards
If you decide to try this be sure to order a cable that has data capability as you need the D+ & D- pins joined together for the center tap on the LiPo cells. You need both pins as the magnetic connector does not care about orientation
Of course this approach still requires you to turn off the robot power switch and monitor charging to later disconnect
Now I'm off to work on the suggestion from @nink and @Jeremie
Frank
Frank
Just be sure the cables support data transfer instead of just charging
The next step in my project is to add @jeremie’s idea of using another robot to provide the charging station
It is powered by a wall adapter instead of a battery and will contain the version 3 charger for the dockable Revolution robot connected through the magnetic connector
Regards,
Frank
I need the D+ D- wires because the charger requires 3 wires to charge the battery
This is because there are 2 cells in the battery that must be balanced charged
Also, I don’t think you need to worry about the orientation of the connector switching polarity as these cables are more the the USB C design where they don’t care about orientation
regards
Frank
Here is a picture of the 2.4 amp cable I purchased. There is 15 cores for data line and 35 for power.
Frank
Works well. I will add them to all my EZ-B great idea! Thanks
Great news
Frank