Breadboarding up the LTC4060 multi-chemistry battery charger was probably the gnarliest wiring challenge I've had thus far. Since I was dealing with power I was extra careful to follow the schematic that I had created based on the data sheet. When I finally had it all set up and I attached my 3-cell battery pack (that I had discharged with a resistor the day before) and then set my power supply to 5V... nothing happened! I then turned everything off, rechecked all the connections, and looked over the data sheet again. Aha! If you set the LTC4060 to 3-cell mode, it requires 7.2V from the power supply! Once I brought of the voltage, I saw the red LED light up to indicate that the system was charging. The system seems like it was in slow charge mode, when I was expecting fast charge, but I can figure that out later.
Getting the ESP-12F module form of the ESP8266 to flash was a little more complicated than the dev module. We had to set a few of the GPIOs to high or low with the buttons and use the reset to put the module into "UART download mode". Once we figured that out, flashing it using the Arduino IDE was a piece of cake. Next up is to build our own firmware capable of doing OTA firmware updates.