NAZE32 flight control 3-inch drone

1. Foreword
This project should be called a cheap installation plan for a cross-country drone rather than a flight control design. The flight control design is basically copied from several naze32 boards on the current platform and then modified casually, which reduces some welding difficulties. It is a reference for people like me who have no money but want to make a decent cross-country drone/quadcopter. Don't ask me why I don't just buy a mobula, because the purpose of making this thing is actually more to tinker with it rather than let it fly...
Finished product:
Can fly normally
https://www.bilibili.com/video/BV1cu411b7Rr/
The conclusion of the test flight is that the combination of 2s+Bai Cai 1104+3018 is too weak for this system. The throttle for takeoff with full power reaches 50%, and the throttle for hovering is estimated to be 60%. It feels very weak, and the battery life is only about 4 minutes. In addition, the motor and battery will be slightly hot after flying, which is obviously too heavy. The solution without upgrading the entire power system is to replace the battery with 3s. As for the effect of 2345 propellers, it has not been tested yet.
 
2. Overall solution
Flight control: naze32 flight control bf3.2.5 firmware
Frame: Johnny 3-inch frame
ESC: blheli split ESC 20A * 4
Motor: Taobao/Xianyu 1104 cheap brushless motor 4300kv
Battery: Eagle Krypton 2S 500mah 100C
Propeller: two options, 2345 propeller or adapter + 3018 propeller
Remote control: Fusi i6
Receiver: rx2apro
Image transmission and FPV part: no, this thing is too expensive, if you really want to buy it, the cost is higher than the above combined, you can only fly visually
 
Cost calculation: flight control (20) + frame (35) + motor (50) + ESC (100) + battery (30) + propeller (15) + remote control and receiver (200) = 450, so you can have a plane that can fly.
 
You can beg for more parts:
ESC: buy the 6A one from Xianyu 10A self-made split ESC, it seems to be more than ten yuan each, saving half the money, but the versatility is unknown (this kind of cheap 1104 motor actually does not need to use 20A ESC, the ESC is bought just for future use)
Remote control: Some unknown domestic control only needs two digits, but to be honest, Fusi i6 is really the most entry-level control, some unknown brand control is enough to drink a pot of receiver protocol, not to mention that it is still an old product like naze32.
 
3. Detailed description
3.1 Flight control
The flight control is designed with a 20*20mm hole spacing (F4mini type), and the overall structure is a pseudo-flying tower design of flight control (4-layer board) + power distribution board (2-layer board). The battery is directly connected to the power distribution board, which can reduce the voltage of 4s and less batteries to 5v, and leave 4 groups of split ESC pads; the power distribution board is connected to the flight control through a 1.25 6p cable, and the 6p is 5V GND, M1-M4 pwm signal respectively.
The flight control is not much different from several naze32 projects on the platform. It is just to reduce the difficulty of welding, the mpu6050 in the qfn package is replaced with the ready-made gy521 module, and the pwm receiver interface is deleted. No one really uses this thing, and the layout is changed to the exposed pad like the current mainstream flight control for easy welding. But one of the bad things about this version of the design is that there is no onboard usb serial port chip and usb socket (mainly because the size is a bit small, so it was deleted when designing the layout for laziness), resulting in the need to connect the firmware and parameters to the external usb-uart module through the flying dupont line.
 
As for naze32 itself, I think this is completely sufficient for getting started. After all, this thing is the predecessor of the f3 flight control and is much more stable than the previous generation cc3d flight control.
3.2 Rack
This is nothing to say. If you want to save money, you can use a pcb rack, but in fact, you can't save a few dollars. The rack I use is quite cheap. This kind of serious carbon fiber rack is much better in terms of appearance and durability.
 
3.3 ESCs
The trouble with ESCs is that they are not like flight controllers (F3 flight controllers are sold for 70 or 80 yuan, but homemade naze32 only costs 20 or 30 yuan, and there is no essential difference between the two). Even if there are a lot of open source designs, you can't save much money if you DIY them yourself, because the board is not only small, but also a lot of qfn-like packaged MOS are difficult to solder, and the cost of components is not low.
Blheli is the mainstream open source ESC now, and ESCs are generally not easy to break as long as they are not overloaded.
 
3.4 The
battery is selected together with the motor. Generally, 4s is the maximum for a three- or four-inch machine. The cheap 1404 used now is not enough to use 3s, so 2s is used.
 
3.5
The positive pole of the motor is actually dozens of yuan for each cross-country motor, because the performance is powerful enough, but the problem is that if a novice does not fly a simulator, it is useless to have a good motor, and you can't do the action. If I use 3018 propellers on the motor of my plane, I can't even control it, so just buy a cheap one for entry, and you don't feel bad if one explodes at ten yuan.
 
3.6 For propellers,
just remember that high kv goes with small propellers, and low kv goes with large propellers. This can be simply understood as high kv means high speed. At the same speed, large propellers have greater thrust. Similarly, if high kv is used with large propellers, the motor may be continuously overloaded, causing the armature current to be too large and burning the motor.
 
3.7 Remote control and receiver
In fact, if you really want to play with a cross-country drone and you are not short of money, you really have to buy a good remote control, because the mainstream receiver solution now is elrs, and most good remote controls are elrs. This thing uses the crsf protocol, and I am not sure if naze32 can parse it. Analog protocols such as pwm and pfm should have been put into the garbage heap of history. As for sbus/ibus like Fusi, only garbage guys like me can use them.
 
3.8 Image transmission and FPV.
If you don’t have enough budget, don’t think about this part, otherwise you will only buy some equipment that is neither good nor bad. If you really want to do it, you can buy a wifi image transmission or a card blind shooting module for a few dozen dollars and hang it on the plane, but the effect is unknown.
 
 
4. To be continued