Table of Contents


Boards

Node MCU

Node MCU who provides the LUA firmware also propose evaluation boards: http://nodemcu.com/index_en.html#fr_54747661d775ef1a3600009e

ESPToy

An Arduino + ESP-01 board, with an ATMega 644: http://rayshobby.net/cart/esptoy

ATMega 644 has two hardware serial ports

Olimex ESP8266-EVB EValuation Board

ESP8266-EVB is Evaluation board for ESP8266 with relay, button, UEXT, all GPIOs available on 0.1“ header https://www.olimex.com/Products/IoT/ESP8266-EVB/

AI-Thinker 'Test Board'

The AI-Thinker board is an evaluation board with an onboard STC15L204EA microcontroller along with a relay, buttons and LEDs on all GPIOs, a relay, a buzzer, LDR, a socket for NRF240 modules, CH340 USB to Serial converter and DIP switches allowing different IO routing configurations to be setup. A small adapter board connects the normal ESP8266 modules to a pair of 2×4 headers. The board is widely available from a number of Chinese vendors, sometimes called a Coexistence Module. This is not the cheaper AI-Thinker “yellow board” (which should have its own entry on this page).

DIP Switches

Serial Data Switch

This is the left-most switch when the USB port is at top. Controls routing of the serial data lines.

No. Label Function
1 DCRON ON=Connect ESP TX line to MCU RX line.
2 DCTON ON=Connect ESP RX line to MCU TX line.
3 ESPTON ON=Connect ESP TX line to CH340.
4 MCUTON ON=Connect MCU TX line to CH340.
5 ESPRON ON=Connect ESP RX line to CH340.
6 MCU_R_ON ON=Connect MCU RX line to CH340.

So, to achieve the following standard configurations set the dip switch as follows:

Configuration 1 2 3 4 5 6
MCU connected to CH340 OFF OFF OFF ON OFF ON
ESP8266 connected to CH340 OFF OFF ON OFF ON OFF
MCU connected to ESP8266 ON ON OFF OFF OFF OFF
IO Switch

This is the right-most switch when the USB port is at top. Controls routing of some of the IO and signal lines.

No. Label Function
1 GPIO14 ON=AC relay controlled by ESP8266 GPIO14
2 DLMCU | ON=AC relay controlled by MCU | | 3 | CHPDH | ON=Enable pull up on CHPD line of ESP8266.
4 GPIO0L | ON=Pull ESP8266 GPIO0 down for flashing. | | 5 | GPIO15L ON=Pull ESP8266 GPIO15 down (normal during boot)
6 GPIO2_L ON=Pull ESP8266 GPIO2 down for ?

Relay

Normally open, it can bridge the two AC terminal connections together. See above for control. High level closes the relay. Handles 3 amps at 35v DC or 3 amps at 250v AC.

Buzzer

Annoying. Apparently controlled only by MCU?

CDS Light Sensor

One is installed on the board, connected to the MCU. Holes for another wired to the ESP8266 ADC are in place but not populated with a sensor presumably because this version breaks out the ADC for independent use.

Schematic

What is apparently an older version may be found in this thread.