# Fifth Lichuang Electronic Design Competition # Large-capacity Bluetooth headset controller

Note: * is required.

[Please fill in during the registration stage↓]

* 1. Self/team introduction

I am an engineer with ten years of experience in electronic hardware and Internet of Things system research. I actually only did one day of development. What I mean is that if you work in a profession for ten years, you must have the spirit of perseverance.

* 2. Briefly introduce the project

This project mainly designs a large-capacity battery-powered Bluetooth headset controller. Make a portable Bluetooth headset, which has not been charged since the beginning of the epidemic.

[Please fill in during the competition stage↓]

* 1. Describe project details

Bluetooth headsets are beautiful and classy, ​​but at the same time, they are also painful.

In 2000, the first wireless Bluetooth headset was launched. 20 years ago, 10 years ago, 5 years ago, the standby time of Bluetooth headsets increased from 1 hour to 10 hours, and then decreased from 10 hours to 1 hour.

No one expected that today’s mainstream would still return to the design of 10 years ago. Why? After historical summary, people always like big ones.

In the past, when mobile phones were not popular, Bluetooth headsets were very high-end and could only play for one hour. Currently, the Bluetooth headsets on the market are all equipped with large-capacity batteries, but in fact they only have 200mA, because any more will damage the ears.

The current popular solution is to use a double-ear strap and hang the battery around your neck. Even so, Bluetooth headsets do not have a truly large capacity and will run out of power after playing for dozens of hours.

So, I made a portable Bluetooth headset, which has not been charged since the beginning of the epidemic.

* 2. Describe the challenges faced by the project and the problems solved

1) The goal of the project is to increase the standby time of Bluetooth headsets. No, let’s get real, play time. How to solve the problem? Configure 18650 power battery for the controller, but it doesn’t work, there are too many cells!

Isn't this a power bank? No, the power bank cannot charge Bluetooth headsets. The few that can be recharged also find it troublesome for us. We carry a power bank, a cable, and a Bluetooth headset. We might as well just bring an ordinary wired headset.

A 200mA battery may damage your ears, but a 2000mA battery won’t damage your ears? I'm afraid it will be heavy even if it is dropped on my neck for a long time.

If you don’t hang it on your ears or around your neck, where can you put it? Trouser pockets, yes trouser pockets, and clothes pockets.

So this requires a line? Yes, needed.

2) What kind of thread is used? Is it longer than the one that hangs around the neck? Well, it's much longer, just use an ordinary wired headset to connect to the controller.

Why not just plug it into your phone? Well, yes, not too bad.

But have you ever tried doing housework? Have you ever imagined a girl without a coat pocket who wants to listen to music while doing housework? Have you ever thought about charging your phone while listening to music, but it’s troublesome to charge your phone at the same time, let alone charging your Bluetooth headset?

3) What should I do if the 18650 battery causes a short circuit due to headphone failure? The MCU is used to monitor the battery temperature in real time and cut off the power supply of the Bluetooth headset in a timely manner as the first line of defense. A battery protection chip is used to switch battery power supply in a timely manner as the second line of defense.

4) What should I do if the fault temperature is too high and the meat is scalded? Over 40 degrees Celsius, intelligent cooling.

5) What should I do if the standby time is too long and it keeps playing when I sleep? Actively turn off the power supply of headphones to protect your ears.

* 3. Describe the key points involved in the hardware and software parts of the project

1) If you don’t like the 300mA charging current of Bluetooth headsets, you can refer to the 18650 charging circuit, 500mA. Higher pursuit, higher parameters. This is not the point, anyway, it needs to be recharged every two years.

2) Charge and discharge protection circuit. Mainly relying on first-level protection. This second level is guaranteed.

3) Bluetooth headset power control, headphone socket

4) Protect the meat. Solder the 10K thermistor snugly to the 18650 battery. The signal is sent to the MCU after voltage division using a resistor, and the temperature value is read and calculated using AD channel 0.

    ad_ave = (u16)(ad_value[0]&0xFFFF);
    g_temp.T_value2 = ad_ave;
    if(g_temp.T_value!=0)
    {
        if(g_temp.T_value2<       (1400-10))//高温
        {
            CTRL_POWER_OFF;
            g_temp.led_flash = 1;
        }
        if(g_temp.T_value2>(1400+10))//低温
        {
            CTRL_POWER_ON;
            g_temp.led_flash = 0;
        }
    }
    g_temp.T_value = g_temp.T_value2;

5) Protect your ears. Power off the Bluetooth headset regularly for 1 hour.

* 4. Project material list display

* 5. Upload project pictures

5.1. If the contest logo is not printed on the PCB, it will be deemed as giving up the participation.

5.2. Other pictures of the project

* 6. Demonstrate your project and record it as a video for uploading

6.1. Video upload contest official website

6.2. Video title and link at Station B

Notes: ①: Video requirements: Please shoot horizontally, the resolution is no less than 1280×720, the format is Mp4/Mov, the size of a single video is limited to 100M; ②: Video upload: please upload to the official website of the competition and Station B simultaneously ([ www.bilibili.com), the top 10 most popular projects at Station B will receive a cash reward of 1,000-5,000 yuan, and other uploaded projects will receive a 100-yuan Lichuang Mall no-threshold coupon; ③: Video title: The 5th Lichuang Electronic Design Competition: {Project Name}-{Video module name}; such as the 5th Lichuang Electronic Design Competition: "Autonomous Driving" project - team introduction.

The 5th Lichuang Electronic Design Competition: Large Capacity Bluetooth Headset Controller Project-Self-introduction.mp4

https://www.bilibili.com/video/BV13541187K1/

The 5th Lichuang Electronic Design Competition: Large Capacity Bluetooth Headset Controller Project-Function Demonstration & Performance Test.mp4

https://www.bilibili.com/video/BV1fp4y1e7iv/

* 7. Whether it is released to the public for the first time

7.1. Please indicate whether the project has been published or won awards before.

no

7.2. If the project is optimized on the original basis, please explain the optimization part

no

* 8. Open source documents

Blueboard v1.0 large capacity Bluetooth headset controller circuit schematic diagram.SchDoc

Blueboard v1.0 large capacity Bluetooth headset controller project source code.zip

Blueboard v1.0 large capacity Bluetooth headset controller BOM.xlsx

* 9. References click on the link for more details: https://www.szlcsc.com/go/dsxq

"C77701_GD32F130F4P6TR_2018-05-08.PDF"