The QDEV-ESP8266 board is a multipurpose Internet Of Things (IOT) module based on the AI-Thinker ESP-12F development module (Espressif ESP8266 SOC). The QDEV-ESP8266 is a powerful and cost effective development/product ready platform with a 'dongle' (aka Rubber Ducky) style form factor which incorporates a male USB-A connector allowing direct plugin to a PC/laptop/Raspberry Pi/etc.

• Espressif Tensilica L106 32 bit low power CPU.
• 80 / 160 Mhz CPU clock speed.
• 80 KBytes of SRAM.
• 4 MBytes of flash memory.
• WiFi module supports IEEE802.11 b/g/n protocol w/embedded TCPIP stack.
• Intergated Inverted F PCB antenna.
• 1 channel 10-bit Analog to Digital converter (ADC).
• 9 GPIO's available with PWM and low power wakeup capability.
• UART supporting baud rates up to 4.608 Mbits/sec.
• I2C, I2S, and SPI interfaces are supported.
• Many examples of SDK support can be found here.
• Auto-programming circuit (eliminates the 'boot' button).
• On board user LED (IO0).

The board can accept either 5 volts or 3.3 volts. 5 volts is normally supplied via the USB-A connector but can also be input on the +5V breakout pin. 5 volt power is regulated down to 3.3 volts using a compact linear regulator. 3.3 volts can also be input on the 3.3V breakout pin.

NOTE: The board I/O pins are not 5V tolerant. Board power on the 3.3V breakout pin or any I/O pin should not exceed 3.3V.

Typical operating current can range from microamps in deep sleep mode to approximately 160 milliamps when transmitting WiFi data.

Signal designators on the bottom of the PCB rotating clockwise:

• RST Chip reset - active low.

• ADC 10 bit analog to digital converter (ADC).

• EN Chip enable - active high.

• IO16 GPIO 16 / Wake from deep sleep.

• IO14 GPIO 14 / HSPI CLK.

• IO12 GPIO 12 / HSPI_MISO.

• IO13 GPIO13 / HSPI_MOSI / UART0_CTS.

• 3.3V Output from internal regulator or Input to board if not powered from USB. *** Note 1.

• CS0 Not user available.

• MISO Not user available.

• IO9 Not user available.

• GND Board ground connect.

• +5V 5V input to the on-board 3.3V regulator (also connected to the USB-A 5V input). 5V input should not exceed 6.5V.

• IO10 Not user available.

• MOSI Not user available.

• SCLK Not user available.

• GND Board ground connect.

• IO15 GPIO15 / MTDO / HSPICS / UART0_RTS. ** STRAPPING PIN **

• IO2 GPIO2 / UART1_TXD. ** STRAPPING PIN **

• IO0 GPIO0 / HSPI_MISO / I2S_DATA. ** STRAPPING PIN **

• IO4 GPIO4.

• IO5 GPIO5 / IR_R.

• RXD UART0_RXD / GPIO3.

• TXD UART0_TXD / GPIO1. ** STRAPPING PIN **

Several pins labeled "Not user available" are used internally by the ESP-12F module. These signals are provided on the breakout pins but should not be connected externally.

Three GPIO pins are used by the ESP8266 to control boot mode. The pin level during boot is as follows:

• IO0 UART download mode - pulldown. Boot from flash - floating or pullup.
• IO2 UART download mode - pullup. Boot from flash - floating or pullup.
• IO15 UART download mode - pulldown. Boot from flash - pulldown.

Additionally TXD0 should be held high during boot. The QDEV ESP8266 manages the state of the strapping pins during boot but any user circuitry connected to these pins should not interfere with the strapping pin states during boot.

NOTES:

1. The 3.3V breakout pin can supply up to 300ma to external circuits. 3.3V power can be input to the 3.3V breakout pin if the board is not being powered from the USB 5V input. Any external voltage applied to this pin should not exceed 3.3V.

2. The ESP8266 MCU is not 5V tolerant. Voltage on any GPIO pin, RXD, TXD, ADC, or RST pin should not exceed 3.3V.

The USB-A connector is the primary development and applications interface for the QDEV-ESP8266 board. The connection provides 5V power to the board which is regulated down to 3.3V using a 500ma linear regulator. The USB-A also allows firmware download via a USB <-> Serial port. Following boot the application can use the Serial port as needed and supports baud rates up to 4Mb/sec.

See the 'Examples' folder for working project ideas.

Firmware can be developed on several platforms such as the Arduino IDE, PlatformIO on VSCode, or the Espressif ESP-IDF development environment. The code examples included here were written using the PlatformIO IDE.

While the Arduino IDE is relatively simple, the advanced features of PlatformIO make it much more compelling and useful to developers.

The Espressif ESP-IDF offers more detailed control of certain features but lacks the rich library support of either the Arduino IDE or PlatformIO and is specific to Espressif devices.

Additionally the QDEV-ESP8266 supports microPython. See Examples for more info.