ESP8266 Module

As part of the testing I want to be able to monitor the ESP8266 pins so I added a buffer and some leds to GPIO0, GPIO2, CH_PD and the reset pin... The two remaining gates on the buffer (4050 IC) are used for level shifting the RX and TX (in the event we have 5 and 3.3 volts supply)....

Power

The board is powered from an external 7 to 12 volts power supply (optional battery header with reverse protection, so allow for ~0.6 volt drop)... The 3.3 volt regulator can handle 1.5 Amps.

Optional Display

Added header for the little TFT (cost $9 or less) to act as console making the board mobile. Basically anything you echo to console can be directed to the display...

Programming the ESP8266

Programming the ESP is accomplished with a little L2303 USB to Serial board and controlled by two switches... A better method might be a 4 pole changeover relay or a single switch if I can find one in KiCad parts... The L2303 is very low cost at less than $2.

The on-board ATMega 328

I've added two 6 pin headers, one for free Analogue pins and another for free Digital. There are also two 3 pin headers for connecting potentiometer or sensors etc...

Miscellaneous

Added 8 pin header to connect to any of the general purpose Leds (active low, with 680R current limiting resistors)... Added reset switches for on board ATMega and another for the ESP8266 reset pin (in case we need it later)...

There's a 10 pin header for an optional 1.8" colour display I use for console output and messages in sketches... It only costs $9 and makes the unit portable (if you add a battery)....

I was positive I added a schematic last night but I don't see it now and the markdown is not behaving?