Play and charge module

Features

• 32 external switches (pulled up - common pole to GND). Based on MCP23017 GPIO expanders in the I2C bus.
• LiPo / Li-ion "1S" battery charger.
• MAX17048 fuel gauge in the I2C bus.
• 3V3 power output for your DevKit board.

Manufacturing and assembly

You must order assembly for this board as it requires SMD mounting. You may want to exclude the pin headers from the BOM and the assembly. This way you can solder the wires directly to the pads. Power and battery headers are already excluded.

This PCB was designed using Easy EDA Pro. If you want to order a PCB to their prototyping service, note that some components are not included in the BOM on purpose. You may receive an error message regarding those. The minimum order is 5 units, but you can choose to assembly only two boards in order to save money.

The manufacturing process is JLC04161H-3313 (4 layers).

Files

• Easy EDA Pro

  Note: you can import this file to KiCAD 9 or later.

• Schematic

• GERBER

• Bill of materials (BOM)

• Pick and place

• Layer manager

Usage

• External power for battery charging:

  • Minimum input voltage: 4.6V.
  • Maximum input voltage: 5.5V. Higher voltages will damage the board.
  • The battery charging current is 300mA.

• This module is designed for a single "1S" battery, maximum 4.7 volts. Do not place batteries in series.

• Only one module can be attached to a DevKit board.

• Hardware addresses of GPIO expanders are fixed to 7 and 0 (decimal).

• The I2C bus is pulled up using onboard 10K-ohm resistors (labeled R4 and R5).

To enable this module in your custom firmware (just an example):

void simWheelSetup()
{
    ...
    MCP23017Expander chip1;
    MCP23017Expander chip2;

    // Place the input numbers you want
    // This is just an example
    chip1[MCP23017Pin::GPA0]=0;
    ...
    chip1[MCP23017Pin::GPA7]=7;
    chip1[MCP23017Pin::GPB0]=8;
    ...
    chip1[MCP23017Pin::GPB7]=15;
    ...
    chip2[MCP23017Pin::GPA0]=16;
    ...
    chip2[MCP23017Pin::GPA7]=22;
    chip2[MCP23017Pin::GPB0]=24;
    ...
    chip2[MCP23017Pin::GPB7]=31;
    ...

    // The following two lines are mandatory
    inputs::addMCP23017Expander(chip1,7);
    inputs::addMCP23017Expander(chip2,0);
    ...
}

...


void customFirmware()
{
   ...
   batteryMonitor::configure();
   ...
}

External wiring

• Use one or more GND pins as a common pole for all the switches.

• There are two SCL and SDA pins. Wire one of each to the DevKit board and use the others as a pass-through to other modules (if required).

• Take care not to swap the polarity of the battery or the external power.

• Take care not to swap battery and external power wires.

• It is advised not to use pin headers for the battery and external power wires. Solder the wires to the pads instead.

The pin out should be printed in the back of the board.

Board size and mounting holes