User manual

The most important pins and designations of the board
The WLAN module is controlled with AT commands. For this, the Arduino part of
the board is connected to the WLAN module via pins 11 and 12. A small circuit
converts the 5-V-levels into compatible 3.3-V-levels. Pins 11 and 12 should not be
used in your own projects for this reason.
Further important hardware properties of the board are summarised in the follow-
ing table.
Technical Data
Microcontroller: ATmega328
Flash memory: 32 kB (including 0.5 kB for the boot loader)
SRAM: 2 kB
EEPROM: 1 kB
Cycle rate: 16 MHz
I/O-pins: 20 (including 2 for communication with the WLAN
module)
U
including PWM: 6
U
including analogue inputs: 6
USB-to-Serial chip: CH340G
Operating voltage: 5 V
Recommended input voltage: 7 – 12 V
Maximum current per I/O-pin: 40 mA
Resilience of the 3.3-V-output: 50 mA
WLAN-module: ESP8266
SPI-Flash 4 Mbit
Operating voltage: 3.3 V
WLAN standards: 802.11 b/g/n
WLAN modes: Wi-Fi Direct (P2P), Soft-AP
Firmware: AT-Firmware Version 0.22
Other Features: Integrated TCP/IP-stack
+19.5 dBm output power in the 802.11b-mode
Integrated Low-Power-32-bit-CPU
Communication via UART