[Training Camp] Robot Dog Legs

Robot dog based on HI3861 chip

Introduction: The main control is the HI3861 chip, which is based on the software and hardware design of Chuanzhi Education’s module and genkipi.

Overall solution: Powered by 7.4V lithium battery, the overall voltage part is composed of 7.4V->5V->3.3V. Since the current required by the steering gear is relatively large, when the steering gear is moving,

The 5V voltage needs to provide quite a lot of current. Since 5V uses a linear power supply, it generates a lot of heat. This is a hardware part that can be optimized. The steering gear control part is

It is processed through the IIC->16-channel PWM PCA9865 chip. The chip provides a 20Khz PWM wave and controls different servos to rotate accordingly through IIC communication.

Note: Since all IO interfaces are introduced, this hardware board can be used as a development board.

In terms of schematic diagram: I made reference to the hardware solution of this training camp without making too many modifications, because I applied for the basic camp but I was worried about the cost when doing the overall dog training, so I made some choices.

However, a circuit is added to control the battery power supply part, which can be set through a switch to provide power when needed to save power.

PCB: Mainly dealing with the power supply part, because the current required by the servo is indeed large. If the main power supply line is not thickened, it will inevitably become hot when the servo moves, causing a current bottleneck.

The phenomenon causes problems with the overall movement. The remaining parts are placed according to use. Four M3 screw holes are reserved to fix the PCB to the board.

Material price: 8 servos for 80 yuan, PCA9865 for 18 yuan, acrylic shell for 25 yuan, battery for 25 yuan, screws for about 12 yuan, PCB Jialichuang board for 0 yuan, remaining materials training camp coupons

0 Yuan Total 160 Yuan

The following is the assembly diagram of the dog. I just started to prepare for 3D printing, so I spent money on the upper plate, bottom plate and tailgate in order to make it cheaper. I checked the price and found that it cost 100 yuan, so I used it anyway.

Acrylic cut.

Note: In actual assembly, the length and installation direction of the screws can easily interfere with the shell, so I installed the legs with the nuts facing outward. I still did not install the servo in a good way.

Self-tapping screws were used for fixation, resulting in part of the fixation sticking out of the case. Pay more attention to the order when wiring the servo, otherwise it will be troublesome to disassemble and try again if you make the wrong connection. due to strength issues

I also added zip ties on the lower legs to ensure that they can provide enough force to support the overall weight of the device. See the picture below for details.

Summary: This training enabled me to learn the use of soilwork, improve my drawing skills, and get in touch with Hongmeng. Then solve the problems encountered in actual production one by one

I gained a lot, accumulated experience, and grew up.