First of all I love your site and everything you have to offer.
I have ordered the RPLIDAR A2 for a new SLAM robot I am about to make. The robot will also be equipped with a Raspberry Pi 3 to send all the data to my server for further data processing.
However, after reading further documentary regarding the Raspberry Pi, I doubt that it’s current USB ports can supply enough juice to keep the RPLIDAR operable. The RPLIDAR uses 1200mAh in operation, and 1500mAh during startup.
However my robot is also equipped with a Xiaomi 20.000 mA powerbank that can supply 2.1A at 5V. It has two USB ports to supply two mechanics with juice.
The problem now is that the juice should come from the powerbank, and also keep the RPLIDAR connected to the raspberry pi for the data.
So my following questions are:
Am I correct about the Raspberry Pi not being able to supply the RPLIDAR if enough energy?
Can I use the Xiaomi Powerbank with the RPLIDAR A2?
If so, what extra hardware do I need to send the data to the Raspberry Pi, and connect the Xiaomi to the RPLIDAR?
If not, do you know what alternative configuration I can use or buy?
I ask these questions because I do not have a lot of experience in electronics or the UART interface. Since the RPLIDAR is quite expensive I would like to make sure I don’t damage or fry anything.
Yes, you are. Most USB host controllers cannot provide more than 500 mA (at most). And even then, it may not be the most stable voltage output due to the current demand. As you can see on page 13 of the datasheet, the power source must not only provide 5 V DC and 1.5 A of current, but it must also do so with very low ripples (~20 mV, max 50 mV).
We do not have any specifications for this power bank, but if it can provide a stable 5 V DC output at 1.5 A or more, you should not have any issues with powering the RPLidar A2.
The Raspberry Pi can still be connected to the adapter board as normal by USB. What will change is that you will need to connect your power source to the mini-barrel connector available on that adapter board. That is the power input port for the device.
As mentioned above (#3), the only way to easily add an external power source is to use the mini-barrel connector on the adapter board.
An alternative would be to place a powered USB hub (that can provide 5 V DC with 1.5 A or more) between the Raspberry Pi and the adapter board.
We are quite happy answering your questions now than doing troubleshooting later after something got damaged, expensive or not!
Unfortunately, we do not currently have any power supply that fits this barrel connector type. Please find attached the datasheet for the jack itself.
Thank you very much with your fast response. Much appreciated.
I’ve read the barrel connector specifications you attached to your message. Unfortunately that doesn’t help me right away. I do have 15 years of programming, but not much when it comes to electronics. A powered USB port is not an option since I want to mount it on a robot.
The manufacturer, CUI INC also doesn’t ring a bell at all.
However, the last lines of the attachment gave me some hope. Mouser Industries seems an Authorised Distributor of CUI INC. Mouser has an office in the Netherlands (where I live), and also in France and the United States. I looked at their website and it looks promising.
I’ll ask them the same questions. I hope that the barrel connector will ring a bell to them. Maybe they know how to connect it or have some extra information / products to connect an external power to the RPLIDAR more easily.
If they are kind enough to give a newbie an answer to my questions, I’ll share it with you all.
For the most part, you really only need to request the part number for the matching connector (the mini-barrel) that connects into the connector that is on the adapter board.
Then, you can solder this connector to the leads of any power supply or battery that is appropriate for this product.
Just a follow up on my question. Everything works fine now.
I ordered 5 PP-012 connector plugs from Mouser.
I was first kind of afraid I actually had to solder the plug to the chip.
Seems like the only thing you need to solder is the wiring to the plug.
I bought an 28/24 20 awa USB cable. Those cables optimised for extra current to charge up phones and tablets.
Chopped of one part and soldered the power line and ground to the plug according to the documentation.
It works absolutely amazing. My Power Bank is big and strong enough to power both the RPLIDAR A2 and the Raspberry Pi.
Now I need to learn how to program it, but the documentation on your website will help me out.
If you feel like it, you could always post about your project here. We are certain the RobotShop community would be interested in learning more about it. You are certainly not the only one starting out with a RPLidar A2.
