#The 4th Startup Contest#Servant--a little servant always on standby

Note: * is a required field.

[Please fill in during the registration phase↓]
* Briefly introduce the work:
With the popularity of smart phones, power banks have become a standard feature of mobile phones for business travelers or people who love to play with mobile phones. Such a popular thing has a single function, and adding additional functions to it has become a problem that countless developers have been thinking about. Society is developing, the pace is getting faster, and frequent business trips are inevitable. I have also been on business trips, and I know the hardship of business trips. My legs are weak when I walk, my waist hurts when I stand, and my shoulders are sore when I carry a backpack. I always hope that someone will serve me when I am tired. From this point of view, adding massage therapy functions to power banks can well alleviate the pain points of this group of people. From the perspective of market prospects, power banks are widely used by a wide range of people, and adding massage therapy functions can solve the pain points of specific groups of people. If there is a product with the same price as an ordinary power bank, but with massage therapy functions, it must be a selling point, because it is no longer a simple "power bank", but a "serving treasure" with massage therapy functions.

【Please fill in during the competition stage↓】
* 1. Details of the work;
    1. Picture display of the work:
        Screenshot of the front of the PCB
        ![image.png]         Screenshot of the back of the PCB
        ![image.png]         PCB shell structure diagram
        ![image.png]         PCB shell structure parts diagram
        ![image.png]
2. Functional description of the work:
   The upgraded version of the power bank of course includes 5V input charging, 5V output power supply and flashlight function. Secondly, massage therapy function is added on the basis of the three basic functions of the power bank. The massage therapy function unit includes three parts: LED gear and mode status display, adjustment setting button, and therapy signal output.

3. The realization principle of the massage therapy function of the work:
   The massage therapy function is realized by the DA of the single-chip microcomputer generating different therapeutic electrical signal pulses. Here I mainly use medium-frequency pulses to realize it. The analog pulses output by the single-chip microcomputer are amplified by the power amplifier and isolated and boosted by the transformer. The signal is led to the wet-electric chip of the massage part through the lead wire, and acts on the massage part of the human body. Under the stimulation of regular medium-frequency electrical pulses, it promotes cell activity in the local area of ​​the human body, accelerates cell metabolism, and enables people to quickly eliminate fatigue and recover.

* 2. Describe the challenges faced by the work and the problems solved;
    Challenges faced:
    Power bank is the most common thing. Its usage method and functional form have been fixed in people's subjective consciousness. When developing products on the power bank, the first thing to deal with is people's subjective acceptance, and the second is the user's cost. Therefore, in this design project of the upgraded version of the power bank (I call it the "Serving Treasure" project), the design concept I have always held is:
     **For things that humans are already familiar with (power bank), without changing its basic usage functions, slightly increase the manufacturing cost, and make a functional upgrade, so that friends who travel around with power banks can always enjoy the service of their families. **
    Problems solved:
    1. The cost has been considered in the selection and design of product components, and the goal is to control the cost within 100 yuan. As far as the current sample production is concerned, it has reached expectations.
    2. The added physical therapy function provides value-added services for people who travel with power banks for a long time, and solves their physical fatigue problems to a certain extent.

* 3. Describe the key points involved in the hardware and software parts of the work;
    I rarely draw PCBs at work. The master knows that I am not an expert when he sees my PCB. It is true. I usually mainly engage in software and product structure design. Of course, I also have some personal interests and ideas after work, and do some research on electronic products. Recently, I have been studying the small four-wheel drive drones that are open source on the Internet. I originally planned to use drones to participate in the competition, but I was always stuck in the take-off stage. Therefore, I changed the plan and chose the project that I had recently made samples and has realized the functions to participate in the competition. It is also an electronic product of "power bank + physical therapy" that I have completed exclusively. I call it "Serve Bao". Serve Bao is not because of work needs or customer customization, but because we all have ideals, pursuits, dare to try, and dare to innovate. It is an electronic product born. Relatively speaking, the information is more complete and the product functions are also realized. I will introduce the key parts here. For schematic diagram and PCB design, I used the AD13 environment that I am used to. Of course, they have been successfully imported into the LiChuang EDA environment. I share
the PCB project link with you: [https://lceda.cn/editor#id=|29e81b8e1e234244804edf4b8e0a2bd0|391eeb6f45e44dba82e88fec94b57b7f](https://lceda.cn/editor#id=%7C29e81b8e1e234244804edf4b8e0a2bd0%7C391eeb6f45e44dba82e88fec94b57b7f)
![image.png] The STM32F103RCT6 processor is used. The processor software mainly realizes key detection, motor vibration, LED light status indication, power on/off, power detection, charge and discharge status detection, flashlight function, serial communication, and physical therapy waveform algorithm processing, waveform output, massage therapy mode processing and other functions.
![image.png]  Charge and discharge interface, flashlight LED and power acquisition circuit.

![image.png] This is the core circuit of the physical therapy function, which mainly realizes the waveform amplification and filtering of the microcontroller output. The audio power amplifier chip is used here. The structure must consider heat dissipation. The function is mainly filtering. The amplification factor of the microcontroller output signal is not very high. The high-frequency transformer realizes the output voltage pull-up, so it is the key component of waveform amplification. The analog switch chip can effectively cut off the output of the massage signal and can effectively disconnect the signal output to avoid the stimulation of the human body by the sharp pulse electrical signal caused by state switching or gear switching.
![image.png] The project directory structure diagram is as above. In the project, the USERmassage.c file is the file that realizes the output of the physical therapy signal. I will share it with you in the last document upload part. When the software realizes the output of analog electrical therapy signals, it must consider the ability of the waveform signal, and it must use an intermediate frequency pulse wave output. Secondly, the amplitude of the output waveform must be adjusted through the DAC of the microcontroller to adapt to the application of people with different physical conditions.

* 4. List of materials for the work;
1 Accessories:
        2.5mm headphone connector ECG lead wire and ECG electrode sheet (online purchase)
2 Shell:
         3 PCB installation structural components, shell, interface baffle and button cap (3D printing)
3 Battery:
         Here I choose a 3.7V 3200mAh lithium battery (online purchase)
4 PCB BOM list (online purchase at LiChuang Shopping Mall), you can also refer to the shared project files.
| 1 | STM32F103RCT6 | U1 |
| 2 | 0603 Capacitor 100nF 10% 16V | C3,C1,C4,C11,C10,C8,C22 |
| 3 | 0805 Capacitor 22uF 10% 16V | C12,C5,C6,C21,C18,C17,C16,C13,C14,C23,C20 |
| 4 | 0603 Resistor 2R 1% 6.3V 1/10W | R9,R44 |
| 5 | CON6-2.0 | J1 |
| 6 | C103 | C7,C9 |
| 7 | 0603 Resistor 10K 1% 16V 1/10W | R8,R3,R1,R2,R14 |
| 8 | USB-A | USB\_OUT1 |
| 9 | USB-A | USB\_IN1 |
| 10 | PH2.0 socket pin 2P | J3 |
| 11 | 1.8nH | L1,L2 |
| 12 | SOD-123 1N4007 F7 1A 1KV | D1,D37,D38,J4-2 |
| 13 | SOT23-6 SX1308 B628 | J2,J5 |
| 14 | SS34 SMD Schottky diode 1N5822 | D2,D4 |
| 15 | 0805 SMD fast recovery fuse 3A | F2 |
| 16 | 0603 resistor 75K 1% 6.3V 1/10W | R6 |
| 17 | 0603 capacitor 15pF 10% 16V | C2,C15 |
| 18 | 0603 resistor 220R 1% 6.3V 1/10W | R5,R15,R43 |
| 19 | 5MM round white LED | D3 |
| 20 | 0805 resistor 51R 1% 6.3V 1/4W | R7 |
| 21 | 0603 resistor 2K 1% 6.3V 1/10W | R11,R4,R10,R17,R18,R19,R20,R21,R22,R23,R24,R25,R26,R29,R30,R36,R39,R42,R35,R38,R41,R46,R47,R49 | |
22 | SOT-23 SI2306 A6SHB | Q2,Q1,Q3,Q4,Q5,Q6,Q7,Q8 |
| 23 | 0805 SMD Fast Recovery Fuse 1A | F1 |
| 24 | 5.2*5.2*1.5 Waterproof SMD Switch | S1,S2,S3,S4 |
| 25 | PJ234 PJ234A SMD Headphone Socket Diameter 2.5mm | PI\_OUT1 |
| 26 | 0603 Resistor 10R 1% 16V 1/10W | R40 |
| 27 | 0805 Capacitor 10uF 10% 16V | C19 |
| 28 | TDA2030a | U3 |
| 29 | 0603 Resistor 100K 1% 16V 1/10W | R34,R32,R37 |
| 30 | 0603 Resistor 4.7K 1% 16V | |
| 1/10W | R27 | |
| 31 | 0603 resistor 20K 1% 16V 1/10W | R28 |
| 32 | 50V/100U | E1 |
| 33 | 50V/470U | E2 |
| 34 | 0603 resistor 240K 1% 16V 1/10W | R16 |
| 35 | SP6201EM5-3.0 | U2 |
| 36 | R512 | R12,R13 |
| 37 | 0603 Everlight Blue | D5,D13,D21,D29,D6,D14,D22,D30,D7,D15,D23,D31,D8,D16,D24,D32,D9,D17,D25,D33,D10,D18,D26,D34,D11,D19,D27,D35,D12,D20,D28,D36 |
| 38 | 0603 Everlight Green | D40,D42,D39,D43,D41,D45 |
| 39 | 0603 Everlight Yellow | D44 |
| 40 | 0408 SMD Small Motor 4*8MM | J7 |
| 41 | 1.8nH | L3 |
| 42 | SOP4 AQY210S | U4 |
| 43 | 0603 resistor 1K 1% 50V 1/10W | R31,R48 |
| 44 | 10R | R45 |
| 45 | CON1 | TOP |
| 46 | BT2.0 | U5 |

* 5. Upload pictures of your work; (The PCB must have the competition logo and take a photo and upload it. If not, it will be deemed as giving up the competition)
1. Soldered circuit boards and accessories from 3D proofing
! [image.png] 2. Servobao charges the phone
! [image.png] 3. Charge Servobao through the USB port
! [image.png] 4. Flashlight lighting function
! [image.png] 5. Physiotherapy function
! [image.png] 6. Samples assembled by Servobao
! [image.png]
* 6. Demonstrate your work and record it into a video and upload it; (The video content must include: work introduction; function demonstration; performance test; close-up of the competition logo on the PCB. If not, it will be deemed as giving up the competition)

Servobao video 0 Usage process demonstration [https://v.youku.com/v\_show/id\_XNDM2Mzk3NjU4OA==.html?spm=a2h3j.8428770.3416059.1](https://v.youku.com/v_show/id_XNDM2Mzk3NjU4OA==.html?spm=a2h3j.8428770.3416059.1)

[Serve the treasure video 1 function introduction](http://v.youku.com/v_show/id_XNDM2MTI5OTMzNg==.html?spm=a2h3j.8428770.3416059.1 "Serve the treasure video 1 function introduction") [https://v.youku.com/v\_show/id\_XNDM2MTI5OTMzNg==.html?spm=a2h3j.8428770.3416059.1](https://v.youku.com/v_show/id_XNDM2MTI5OTMzNg==.html?spm=a2h3j.8428770.3416059.1)
[Serve the treasure video 2 Charge and discharge function](http://v.youku.com/v_show/id_XNDM2MTI5OTMyNA==.html?spm=a2h3j.8428770.3416059.1 "Serving treasure video 2 charge and discharge function")[https://v.youku.com/v\_show/id\_XNDM2MTI5OTMyNA==.html?spm=a2h3j.8428770.3416059.1](https://v.youku.com/v_show/id_XNDM2MTI5OTMyNA==.html?spm=a2h3j.8428770.3416059.1)
[Serving treasure video 3 Physiotherapy massage function](http://v.youku.com/v_show/id_XNDM2MTI5OTM3Ng==.html?spm=a2h3j.8428770.3416059.1 "Serving treasure video 3 physiotherapy massage function")[https://v.youku.com/v\_show/id\_XNDM2MTI5OTMyNA==.html?spm=a2h3j.8428770.3416059.1](https://v.youku.com/v_show/id_XNDM2MTI5OTMyNA==.html?spm=a2h3j.8428770.3416059.1)

VII. Open source documents.
All materials are open source and are only for study and research. They cannot be used for commercial purposes without my permission.