Teardown: Cheerson CX10 Mini Quadcopter

[8086]

Bought one of these on a whim last Thursday, thought a teardown was in order! What do you get in a £12 mini quadcopter?


http://www.banggood.com/Cheerson-CX10-CX10-Mini-24G-4CH-6-Axis-LED-RC-Quadcopter-RTF-p-926614.html

It's definitely a neat little toy, and yes it does fly, very well in fact. So of course I was keen to see what's under the hood.

With the rotors removed:


The underside:


You can see the 100mAh battery, and the four retaining screws.

They look like small machine screws, rather than self tappers.


Well, what do we have here? No chip-on-board epoxy blobs, a few QFN ICs.


Top middle, the IC is labelled "XN297", which looks to be the 2.4GHz receiver - a "wireless mouse solution" by a company called Panchip: http://www.panchip.com/en/products_show.aspx?cid=70&id=351

I assume the controller contains another XN297, I didn't take it apart.

To the left is an Invensense MPU-6050 - an integrated 3 axis gyro and 3 axis accelerometer. Whether it's real or fake is anyone's guess, they seem too expensive to put the real thing in a £12 product. http://www.invensense.com/mems/gyro/mpu6050.html

To the right is a STmicro STM32 F050K4 MCU.

There is also an LED in each corner - blue at the front, orange at the back.

Let's flip the board over:


To the top is the PCB antenna, coming through from the other side.

Underneath that is a 16MHz crystal.

The 5-pin IC just below the date marking is marked "F04A", which could possibly be a 4.5V threshold detection IC - a really basic battery charge cut off, perhaps. Now I know this is in here, I won't be trusting it while charging anymore. There is no charging IC.

Interestingly, pin 4 of the aforementioned IC isn't actually soldered to the PCB - it's left hanging, over some silkscreen. Not sure what that's about.

Each of the ICs on the four 'arms' is marked "004H", I assume just a simple transistor or something to drive each motor.

The LiPo battery is marked "751517", 3.7V, 100mAh.

Here's a gallery with a few more pictures: http://imgur.com/a/jBN4E

[SeanB]

Is that battery swelling so much already? Seems to be close to the point of doing an in air flame out session.

[SodaAnt]

Is that battery swelling so much already? Seems to be close to the point of doing an in air flame out session.

That's what I thought too, but it looks like it just might be at an odd angle, and not actually puffed at all.

[8086]

The battery is about twice as thick as a normal LiPo, and it seems to be intentional. It doesn't seem to have swelled to me.

[arekm]

There is a giveaway for these (2 units) currently: http://forum.banggood.com/forum-topic-35494.html

[janekm]

Thanks a lot for posting that, I was curious about what's inside these!

[snip]


To the top is the PCB antenna, coming through from the other side.

Underneath that is a 16MHz crystal.

The 5-pin IC just below the date marking is marked "F04A", which could possibly be a 4.5V threshold detection IC - a really basic battery charge cut off, perhaps. Now I know this is in here, I won't be trusting it while charging anymore. There is no charging IC.

Interestingly, pin 4 of the aforementioned IC isn't actually soldered to the PCB - it's left hanging, over some silkscreen. Not sure what that's about.

Each of the ICs on the four 'arms' is marked "004H", I assume just a simple transistor or something to drive each motor.

The LiPo battery is marked "751517", 3.7V, 100mAh.

Here's a gallery with a few more pictures: http://imgur.com/a/jBN4E

That SOT23-5 part is an LDO, it's needed as the parts on the other side can't operate at above 3.3V. It's the standard pinout of a so23-5 LDO with a bypass pin. The bypass pin can be connected to a small, low-leakage capacitor to ground to improve noise performance. Putting the pin on top of the ground plane with solder mask + silkscreen in-between is a cute idea for a 0-cost capacitor

The charger IC is bound to be inside the charging cable (it makes sense not to carry that around while flying).

The MPU6050 might be a recycled part... I don't think there's actual fakes yet as the manufacturing technology for MEMS gyros is pretty challenging, and it wouldn't fly so great without gyros

You can always learn something interesting from taking apart Chinese toys...