Guide

This aims to provide a general overview of the badge, important stuff, troubleshooting and building/flashing.

Power

The PWR IN header accepts up to 6v only, this is good for either a USB power bank or a single cell lithium battery.

There is no reverse polarity protection! I don't know exactly what would happen if you connected the supply in reverse polarity, I haven't tried.

If using a bare battery keep in mind that there is no voltage detection or protection on the board (other than the internal supply voltage measurement on the ESPs ADC) and that the regulator will operate as far down as 3.3V.

Therefore it is your responsibility to make sure the cell voltage of a battery used to power the board does not fall too low.

An ideal battery to power the board if only used for low power applications (i.e. no WiFi, no NeoPixels and no external modules) is a 240mAh or 380mAh micro quad (e.g. Hubsan) battery.

I find that when the battery voltage does start to fall the MCP23017 is the first device to fail, which is noticeable by the buttons becoming unresponsive.

Assembly

Most of this is self explanatory, but just a few pointers:

• Do not reflow solder the ESP12 (reflowing my bridge vias on the ESP and the Dilbert board)
• Reflow solder the NeoPixels (it is much more difficult to make an arse of reflowing them)
• Mod wires must be added to connect the ground of the first NeoPixel and the VCC of the last NeoPixel
• Make sure everything works before soldering in the LCD, the holes are tight enough for a good connection to be made without soldering

MCP23017

There are a pair of solder bridge pads near the X1 designator (bottom left of the ESP12) that connect the interrupt output of the MCP23017 to the TXd of the ESP8266 UART.

This connection is made by default using a small trace between the pads. It can be removed easily with a small screwdriver by scraping the trace between the pads away and remade by flowing solder over the pads.

If you have issues flashing the board that are not due to lack of power then try breaking this connection.

Software

There are a few examples that show how to do most things you would want to do on the board.

Graphics are handled by the Adafruit GFX library, NeoPixels are handled by the Adafruit NeoPixel library, if you choose to use the additional IO pins of the MCP23017 they are accessed using the [Adafruit MCP23017 library](https://github.com/adafruit/Adafruit-MCP23017-Arduino-Library), buttons are managed using Universal Inputs.

Instances to the drivers of each of these devices are provided by the Dilbert object:

• Display: Dilbert::display()
• NeoPIxels: Dilbert::neoPixels()
• MCP23017: Dilbert::io()
• Buttons: Dilbert::buttons()

The backlight intensity can be set using either Dilbert::setBacklight(uint16_t) where the parameter is a value between 0 and 1023 or Dilbert::setBacklightOn(bool) where the parameter is a boolean denoting either full brightness or off.

When handling buttons events from Universal Inputs the IDs are enumerated as:

• Dilbert::BUTTON_UP
• Dilbert::BUTTON_DOWN
• Dilbert::BUTTON_LEFT
• Dilbert::BUTTON_RIGHT
• Dilbert::BUTTON_A
• Dilbert::BUTTON_B

The values of the IDs correspond to the IO on the MCP23017 the button is connected to.

If using the spare IO pins of the MCP23017 be sure not to change the global interrupt configuration or the individual pin configurations of any pin connected to a button.

Flashing

• Clone this repository
• Run ./init_submodules.sh (this downloads git submodules containing libraries)
• Install PlatfromIO
• Connect the badge via an FTDI adapter
• Hold the SWD switch and press the RESET switch, keeping SWD pressed while the ESP8266 resets (the LED on the ESP12 should blink once)
• cd firmware
• pio run -t upload
• ???
• Profit

SD card slot

There is an SD card slot, it shares the SPI bus with the display.

It's chip select pin is connected to the RXd pin of the ESP8266 UART.

I have not tested it but it should probably work OK with the SdFat library.