Hi guys just wondering if someone was able to help me with my project.
Basically, I need components to build an automated lid, similar to a sensor bin lid. The lid would lift when a senor is triggered from a distance away, in the range of 1m+.
The components need to be Raspberry Pi compatible and the senor and receiver/transmitter needs to be Zigbee compatible.
Components needed;
• Which Raspberry Pi?
• Which Motor Driver?
•
Could you please help me with the list?
Sounds like a great project, I’ll include some links to similar projects.
To interface the Zigbee network with the Pi you will need a USB adapter to sniff the ZigBee network and allow communication between your Pi and the sensor.
As for the transmitter, to start off with using an Arduino with a ZigBee module (using the XBee form factor)
We have a great shield here:
in conjunction with the XBee module:
To be able to test your components easily I would get I2C sensors so that you can use them with an Arduino and the Raspberry Pi.
On the same note to begin with, I would recommend experimenting a Pi with the model B form factor such as the Pi 3B+ or the Pi 4B (2GB, 4GB and 8GB) then moving to a Raspberry Pi Zero WH once you are confident with the implementation of your project.
As for a motor driver that will depend on the motors you are using, this driver here covers stepper motors and DC motors.
Another option would be a servo motor.
Selecting the motor will depend on the mechanical nature of how you are opening the lid and the torque required from the motor, to ‘move’ power you can use a lever or gearbox to exchange torque for speed. (In a mechanical system power is defined as speed x torque)
If you have any questions about a particular part of your project we can help you out!
What do you mean exactly by charging as it lands? Do you mean you land it on a special charging pad that can make an electrical connection automatically and start charging the battery once you’ve landed it? Or?
Hmm unless you’re a control systems guru, there’s only really two options - some kind of mechanical connector that will fall into place is you land, like they use for Aerial refuelling or get rid of physical connectors altogether with a wireless charging setup.
Either way, you’re going to need to be fairly accurate with your landings. Wireless charging is probably the easier way to go, but the downside is that it’s quite slow and the efficiency is terrible. That said, DFRobot have some relatively high power transmitter receiver pairs:
The two coils pretty much make a basic air-core transformer.
When charging batteries there are two major factors to be aware of that determine the speed of the charge, and how full the battery will be when the charging is complete. That’s the charging current and forward voltage. Essentially, you need to set up a circuit that pushes electrons back the wrong direction that they would normally go when some resistance (or load) is put on the battery by proving more ‘push’ in the other direction.
Luckily for us, we don’t need to consider any of the math behind this, as there are breakout boards, that based on the capacity and chemistry of your battery take care of all of that for you. When you say 3A I’m assuming you mean 3.7V single cell LiPo at 3000mAh capacity, just about any of the charging boards should be able to charge that (be sure to double-check as it can be quite dangerous if anything goes wrong).
This is usually designed for charging batteries from solar panels, but if you desolder the barrel jack connection and hook up the 5V 5A wireless module output in place of it on the drone. Then hook up the drone battery to it (check the description to see how to change the charging current) then it should be able to charge the drone battery after landing if the modules are close enough. Best of luck with the project! If possible, do you think you could share a video on youtube unlisted or google docs when this is done? I’m excited to see how it goes!
If I attached 4x receivers to the feet of the drone and 4 transmitters as the base to guarantee larger surface area/ contact, would you say that this would be a better and faster way of charging the battery?
By the looks of it, you’ll likely need a larger charging breakout than I’ve recommended. What you’ve got there is a 3-Cell battery, I’d check out Phaser FPV, they’re likely your best bet for a breakout of that size from Australia, we don’t stock much that would be suitable in this specific application.
Yes, having multiple receiver setups should help. Although be careful of how you’ve connected them, as if there’s multiple ‘connected’ at the same time you may generate a differential voltage where the output on one is significantly higher than the other causing all kinds of chaos heating up connections and such if you’re not careful in designing the rig from the start.
Multiple receivers is probably not the best way to go. Like Bryce said, you’ll end up with voltage differentials and the voltage regulators will fight each other. You’d need some fancy gear to deal with it - check out this research paper on the topic:
However, what you could set up, is to have multiple receivers and just select the most powerful one to charge your drone - still a bit tricky.
In the end, your best bet is to just be a good pilot That or place your drone on a charging station.
FYI, here’s a video from a start-up (looks like they’ve shut down as their website no longer exists) that does what you’re chasing:
That or place your drone on a charging station.
