Wemos D1 mini is like a "little Arduino with wifi" for a great price. It's based around the ESP8266, has one analogue port and 11 digital ports. It's programmed via micro-USB (or remote flash via wifi). You can use it with the Arduino IDE, micropython or NodeMCU.
It runs from 5V or 3.3V. Logic levels are 3.3V for all ports.
If you use the Arduino IDE, there are a lot of example sketches already provided. This makes life relatively easy to be able to do what you want.
I used these to read temperatures in various locations and send the data to a Raspberry Pi web server via wifi.
They work well with TMP36, DS18B20, RasPiO InsPiRing RGB LEDs, PIR motion sensors, BME280 barometric pressure/temperature/humidity sensors
Tutorials
Documentation
Microcontroller | ESP-8266EX |
---|---|
Operating Voltage | 3.3V |
Digital I/O Pins | 11 |
Analog Input Pins | 1(Max input: 3.2V) |
Clock Speed | 80MHz/160MHz |
Flash | 4M bytes |
Length | 34.2mm |
Width | 25.6mm |
Weight | 10g |
Pin
Pin | Function | ESP-8266 Pin |
---|---|---|
TX | TXD | TXD |
RX | RXD | RXD |
A0 | Analog input, max 3.3V input | A0 |
D0 | IO | GPIO16 |
D1 | IO, SCL | GPIO5 |
D2 | IO, SDA | GPIO4 |
D3 | IO, 10k Pull-up | GPIO0 |
D4 | IO, 10k Pull-up, BUILTIN_LED | GPIO2 |
D5 | IO, SCK | GPIO14 |
D6 | IO, MISO | GPIO12 |
D7 | IO, MOSI | GPIO13 |
D8 | IO, 10k Pull-down, SS | GPIO15 |
G | Ground | GND |
5V | 5V | - |
3V3 | 3.3V | 3.3V |
RST | Reset | RST |