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====== USB-C-ifying ======

Having several different chargers for devices is tedious. Read about how to convert nearly everything into USB-C. \\

It can be done two ways: \\
   * modify the device itself \\
   * create a fake battery pack with USB-C socket, reusing original BMS (Battery Management System) \\


There are three ways how to do it electronically: \\

   - no voltage adjustment needed = there is already micro-USB or a socket with 5V \\
   - use step-up or step-down electronics to match voltage of the device \\
   - use USB-PD (with PPS) or Quick Charge (QC) to request voltage of fast chargers \\

Terminology: PD = Power Delivery   ;   PPS = Programmable Power Supply \\


**Category 1:** Solder in a USB-C socket - there are available USB-C breakout boards for easy of use. For some devices there are replacement boards with USB-C so it is easy to convert them. Examples are PlayStation DS4 controllers and PS Vita. There are solderless boards/kits offered. \\

**Category 2:** The voltage of the device is not 5V. To lower voltage, a linear regulator (LDO) can be used (e.g. to 3V3 with AMS1117-3.3) - they are small and cheap but also inefficient and may get hot, as LDOs just burn up the excessive voltage. There are switching regulator modules which are more efficient but bigger in size and more expensive. Bad modules may have high voltage ripples. \\

**Category 3:** Chose USB-PD if voltage should be adjusted inside the charger. Regular USB-PD is >=5V. PD with PPS can go as low as 3.3V. \\



**TIP:** If you solder in a USB-Socket, you need to fixate it somehow. If there used to be a micro-USB socket, there is mostly a ground pad beneath it. Apply solder tin on the upper side of USB-C socket and solder it upside-down onto the ground plane of the PCB. \\


===== #TODO: USB-PD and PPS =====
Regular USB-PD is >=5V. PD with PPS can go as low as 3.3V.
Typically, PPS allows continuous adjustment in 20 mV steps. 
USB-PD PPS IC (like CH224K or IP2736) 


In USB Power Delivery (PD), a PDO (Power Data Object) describes a power option that a source (charger) can offer to a sink (device).
Fixed PDOs: Advertise fixed voltages (5 V, 9 V, 15 V, 20 V).
Variable PDOs (deprecated): Used in older PD specs, allow requesting a voltage within a range.
Battery PDOs: Specify a power range in watts instead of volts.
APDOs (Augmented PDOs)
Introduced in USB PD 3.0 to support PPS (Programmable Power Supply).
Instead of just offering a fixed voltage, an APDO defines a range and step size.
The sink can request a specific voltage (in 20 mV steps) and current from the source.
Example APDO from a charger:
"PPS: 3.3 V – 11 V @ 3 A"
Sink could request 3.8 V, 5.6 V, 7.2 V, … within that range.
APDOs are PDOs that describe a programmable voltage range (for PPS), not just a fixed level.


===== #TODO: modified battery as USB-C dummy =====

Modify a (broken) battery to use as a dummy with USB-C. Also useful for devices which cannot be powered w/o battery (and you only need the device stationary). \\
Caution: Do not accidentally cut into the LiPo battery! Beware of health issues.
Reuse the original BMS and replace the cells of a battery pack cells with electronics to get ~7.2V.  Add a diode in case you accidentally try to power (and therefore charge) the fake battery via charging port of the device! \\
All you need is the BMS, a USB-C socket and a step-up module - alternatively use a USB-PD PPS IC (like CH224K or IP2736) to request ~7.2V \\