USB-typec-power meter-QC decoy-PD

    What's going on with DIYing a power-z? Everyone looks at the review of the charging head website. I believe everyone is familiar with the power meter, but what is going on when DIYing a power-z? Let us take you through it.     DIY a power-z. In fact, UP is too poor to make a power meter. You may be surprised how UP can DIY a power-z? But it was what it was, and I was very surprised.

    This is about DIY a power-z, everyone has...

Stop stopping the old marketing account hhhhh

Indeed, we can’t afford the price of 300 yuan.

The core of the power meter is still Ohm's law, P=UI

If we can’t afford it, why don’t we make one?

Station B column: https://www.bilibili.com/read/cv5712405

Video: https://www.bilibili.com/video/bv15K41157FR

Coolan: https://www.coolapk.com/feed/18304722?shareKey=N2Y0MzcwYjJjYWIzNWVhOTFlZDA~&shareUid=1387916&shareFrom=com.coolapk.market_10.1

The main control uses STM32F103C8T6  , which is overqualified. If you are pursuing volume, you can also use F030, or STC8, which costs only a dollar.

INA226 for AD acquisition  can measure current and bus voltage, which is very convenient. The maximum offset voltage is 10uv.

Using a 10mΩ resistor is just enough to achieve an accuracy of 1ma.

EEPROM uses  AT24C256  (mainly Lichuang basic library patch without adding money)

The HT-7533 is used for power supply, mainly to save trouble and reduce noise, and to provide a clean environment for 226

The maximum input current of 7533 is 30V and 100mA is more than enough.

Using a USB switching chip, it can switch to the QC deception mode and cooperate with the resistor voltage divider to achieve QC deception.

The PD chip FUSB302 has also been added, but we may not necessarily use it. The circuit may not be right, but we don’t want to mess with it. You can tinker with it when you have time.

So there are the first version of the schematic PCB details:

Tell me about the problem

1. The sampling resistor 50mΩ caused the overall internal resistance to be too large. K20P could not trigger 27W fast charging and was later changed to 10m.
2. After changing the resistor, high-current sampling was no longer needed. Later, I also found that there were a lot of problems with high-end differential amplification in ordinary op amps. It was no longer necessary. The sampling resistor became smaller, and the current was no problem up to 8A.
3. The contact resistance of the USB male port is too high, about 50mΩ, just spend money to buy a better one.
4. The first version is for verification. It does not pursue the ultimate size and size. The screen also uses modules. You can modify it to use a smaller size.
5. There seems to be a problem with the QC decoy of low voltage, it needs to be verified, but there is no problem with high voltage.
6. The code is poorly written and patched together, and I'm too lazy to optimize it. Let's just figure it out. Data storage has not been written yet, maybe it will be done in the future (I am really not cooing)

The source code is not open source for the time being. It is poorly written, and the storage function has not been finished yet. It will be open sourced after it is finished.

See the attachment for the HEX file, and you can use it directly after burning it.