Grove - UART Wifi V2

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Grove - UART WiFi is a serial transceiver module featuring the ubiquitous ESP8285 IoT SoC. With integrated TCP/IP protocol stack, this module lets your micro-controller interact with WiFi networks with only a few lines of code. Each ESP8285 module comes pre-programmed with an AT command set firmware, meaning you can send simple text commands to control the device. The SoC features integrated WEP, WPA/WPA2, TKIP, AES, and WAPI engines, can act as an access point with DHCP, can join existing WiFi networks and has configurable MAC and IP addresses.


Parameter V1.0 V2.0
Product Release Date 24th Jue 2016 26th Mach 2018
WiFi Chip ESP8266 ESP8285
Antenna Type External On-board
LEDs 3 LEDs-Power/WiFi/AT Command 2 LEDs- Power/WiFi
Button 1 Button:
Short press to Reset
Long press to enter UART boot mode
2 Buttons for those two functions


You may ask what is the difference between ESP8266 and ESP8285. The ESP8285 is an update version of ESP8266, which adds a build-in 1MB flash. Except that, they are almost the same.


  • Grove 4-pin connector (RX,TX,VCC,GND)
  • 802.11 b/g/n protocol (2.4GHz)
  • WiFi Direct (P2P), soft-AP
  • Supports three modes: AP, STA and AP+STA coexistence mode
  • Integrated TCP/IP protocol stack
  • LwIP (lightweight IP)
  • Integrated low power 32-bit CPU could be reprogrammed as an application processor
  • Integrated temperature sensor
  • Serial UART Interface
  • Multi-queue QoS management
  • Wake up and transmit packets in < 2ms
  • Metal shielding
  • On-board ceramic antenna
  • Reset switch


More details about Grove modules please refer to Grove System


  • Input voltage: 3V / 5V
  • Baud Rate: 115200
  • Based on ESP8285 ESP-06 SoC
  • AT Firmware: esp_iot_sdk_v1.1.0
    • Register red WiFi LED to the ESP8285 wifi state LED.
  • AT command set
  • SDIO 1.½.0, SPI, UART
  • Five power states: OFF, DEEP_SLEEP, SLEEP, WAKEUP and ON.
  • Standby power consumption of < 1.0mW (DTIM=3)
  • Integrated TR switch, balun, LNA, power amplifier and matching network
  • Integrated PLLs, regulators, DCXO and power management units
  • +19.5dBm output power in 802.11b mode
  • Power down leakage current of <10uA
  • Hardware accelerators for CCMP (CBC-MAC, counter mode), TKIP (MIC, RC4), WAPI (SMS4), WEP (RC4), CRC
  • WPA/WPA2 PSK, and WPS driver
  • A-MPDU & A-MSDU aggregation & 0.4ms guard interval
  • Dimensions: 25.43mm x 20.35mm

Ultra-low power technology

The ESP8285 was designed to achieve very low energy consumption with patented power management technology that reduces non-essential functions and regulates sleep patterns. There are five power states:

  • OFF
  • DEEP_SLEEP - the real-time clock runs but all other parts of the chip are closed
  • SLEEP - consumes less than 12uA with only real-time clock and watchdog running. The chip will wake on MAC, host, RTC or external interrupt.
  • WAKEUP - the system is changing from a sleep to on state. Crystal oscillator and PLL are enabled.
  • ON - consumes less than 1.0mW (DTIM = 3) or 0.5mW (DTIM = 10).

The Real-time clock can be programmed to wake the ESP8285 within a specified period of time.

The higher the DTIM period, the longer the device may sleep and therefore the more power the device may potentially save.

To meet the power requirements of mobile applications and wearable electronics, to reduce the overall power consumption, the PA output power can be customised in the firmware.

Application Ideas

  • Home automation
  • Sensor networks
  • Mesh networking
  • Wearable electronics
  • Baby monitor
  • Network camera
  • Industrial wireless control
  • WiFi beacons
  • Smart power plug
  • Location-aware applications

Getting Started

After this section, you can make Grove - UART WiFi run with only few steps.

Play With Arduino


If this is the first time you work with Arduino, we strongly recommend you to see Getting Started with Arduino before the start.

Materials required

Seeeduino Lite Grove-OLED Grove-UART Wifi
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Get One Now Get One Now Get One Now


1 Please plug the USB cable gently, otherwise you may damage the port. Please use the USB cable with 4 wires inside, the 2 wires cable can't transfer data. If you are not sure about the wire you have, you can click here to buy

2 Each Grove module comes with a Grove cable when you buy. In case you lose the Grove cable, you can click here to buy


  • Step 1. Connect Grove-UART Wifi to port SERIAL of Seeeduino Lite.

  • Step 2. Connect Grove-OLED to port I2C of Seeeduino Lite.

  • Step 3. Connect Seeeduino Lite to PC via a Micro-USB cable.


// test grove - uart wifi
// scan ap and display on Grove - OLED 0.96'
// Loovee @ 2015-7-28

#include <Wire.h>
#include <SeeedOLED.h>

char ap_buf[30][16];
int ap_cnt = 0;

void setup()

    SeeedOled.init();                   // initialze SEEED OLED display

    SeeedOled.clearDisplay();           // clear the screen and set start position to top left corner
    SeeedOled.setNormalDisplay();       // Set display to normal mode (i.e non-inverse mode)
    SeeedOled.setPageMode();            // Set addressing mode to Page Mode


void loop()
    ap_cnt = 0;
    SeeedOled.putString("Wifi Scan..."); 



// send command
void cmd_send(char *cmd)
    if(NULL == cmd)return;

// wait result of ap scan
// +CWLAP:(3,"360WiFi-UZ",-81,"08:57:00:01:61:ec",1)
void wait_result()
        char c1=0;
            c1 = Serial1.read();
            if(c1 == 'O' && 'K' == Serial1.read())return;       // OK means over


            int d = 0;
                if(Serial1.available() && '"' == Serial1.read());      // find "
                            char c = Serial1.read();
                            ap_buf[ap_cnt][d++] = c;
                            if(c == '"' || d==16)
                                ap_buf[ap_cnt][d-1] = '\0';
                                goto LOOP1;

// display
void display_ap()
    char strtmp[16];
    sprintf(strtmp, "get %d ap", ap_cnt);

    SeeedOled.clearDisplay();           // clear
    SeeedOled.setTextXY(3,3);           // Set the cursor to Xth Page, Yth Column
    SeeedOled.putString(strtmp);        // Print the String


    int cnt = ap_cnt;
    int offset = 0;
            for(int i=0; i<8; i++)
                SeeedOled.setTextXY(i,0);           // Set the cursor to Xth Page, Yth Column
                SeeedOled.putString(ap_buf[8*offset+i]);        // Print the String
            for(int i=0; i<cnt; i++)
                SeeedOled.setTextXY(i,0);           // Set the cursor to Xth Page, Yth Column
                SeeedOled.putString(ap_buf[8*offset+i]);        // Print the String


  • Step 4. Upload the demo. If you do not know how to upload the code, please check How to upload code.

Then you will see the OLED show the wifi AP around you.

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Firmware update

Our module board got a firmware burned into it for factory settings, you can burn other firmware to it if you like. Click here to download source code of factory setting firmware.

Materials required

  • A USB to serial converter is required for firmware updating, you can choose UartSBee V5 if you don't know where to get one.
  • A Grove-Jump converting cable is required and we also offered for sale.
  • A micro USB cable(type A to type C) is required.


Step 1. Connect one end of Grove-Jump converting cable with grove socket on Grove - Uart Wifi and connect other end with UartSBee V5 which shown as following.

Step 2. Then connecting cables like following figure:

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Step 1. Download burning tool and firmware

Step 2. Press and hold button until the red LED indicator turn on which means it is ready to burn firmware.

Step 3. Start executable files in FLASH DOWNLOAD TOOLS files (double click) to make configurations like following steps:

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1. Choose desired files from firmware bin file downloaded.

2. Select the SpiAutoSet checkbox.

3. Choose COM port and BAUDRATE.

4. Click START button

  • Progress bar will be displayed in firmware-burning process.

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  • Finally, firmware-burning is done.

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AT Commands

Quick start of AT Commands


The Materials required and Hardware connection are the same as Firmware update

Let's go to software part


You can use any serial Tools you like, we use Arduino here. And please make sure you have connect the USB to serial converter to your PC.

Step 1. Open the Arduino IDE, Click Tools choose the corresponding Port.

Step 2. Then click the button on the upper right corner to open the Serial Monitor of Arduino.

Step 3. Set the Serial Monitor as the following picture. Particularly :2- Select Both NL & CR, 3-Set the baud rate to 115200

Step 4. Tap the AT command you need in the 1- command line then click the 4- Send button. You will see the return information as the picture above.

Basic AT Commands

Command Description
AT Test AT startup
AT+RST Restart module
AT+GMR View version info
AT+GSLP Enter deep-sleep mode
ATE Enable/Disable AT commands echo
AT+RESTORE Factory Reset
AT+UART UART configuration(Deprecated)
AT+UART_CUR UART current configuration (Won't save to Flash)
AT+UART_DEF UART default configuration (Save to Flash)
AT+SLEEP Sleep mode
AT+RFVDD Set RF TX Power according to VDD33

WiFi AT Commands

Command Description
AT+CWMODE WIFI mode (Deprecated)
AT+CWMODE_CUR Current WIFI mode (Won't save to Flash)
AT+CWMODE_DEF Default WIFI mode (Save to Flash)
AT+CWJAP Connect to AP (Deprecated)
AT+CWJAP_CUR Current Connect to AP (Won't save to Flash)
AT+CWJAP_DEF Default Connect to AP (Save to Flash)
AT+CWLAP Lists available APs
AT+CWQAP Disconnect from AP
AT+CWSAP Configure softAP (Deprecated)
AT+CWSAP_CUR Configure current softAP (Won't save to Flash)
AT+CWSAP_DEF Configure default softAP (Save to Flash)
AT+CWLIF List stations connected to softAP
AT+CWDHCP Enable/Disable DHCP (Deprecated)
AT+CWDHCP_CUR Current Enable/Disable DHCP (Won't save to Flash)
AT+CWDHCP_DEF Default Enable/Disable DHCP (Save to Flash)
AT+CWAUTOCONN Connect to AP automatically when power on
AT+CIPSTAMAC Set station mac address (Deprecated)
AT+CIPSTAMAC_CUR Set station mac address (Won't save to Flash)
AT+CIPSTAMAC_DEF Set station mac address (Save to Flash)
AT+CIPAPMAC Set softAP mac address (Deprecated)
AT+CIPAPMAC_CUR Set softAP mac address (Won't save to Flash)
AT+CIPAPMAC_DEF Set softAP mac address (Save to Flash)
AT+CIPSTA Set station IP address (Deprecated)
AT+CIPSTA_CUR Set station IP address (Won't save to Flash)
AT+CIPSTA_DEF Set station IP address (Save to Flash)
AT+CIPAP Set softAP IP address (Deprecated)
AT+CIPAP_CUR Set softAP IP address (Won't save to Flash)
AT+CIPAP_DEF Set softAP IP address (Save to Flash)

TCP/IP AT Commands

Command Description
AT+CIPSTATUS Get connection status
AT+CIPSTART Establish TCP connection or register UDP port
AT+CIPSEND Send data
AT+CIPSENDEX Send data, if or "\0" is met, data will be sent
AT+CIPSENDBUF Write data into TCP-send-buffer
AT+CIPBUFRESET Reset segment ID count
AT+CIPBUFSTATUS Check status of TCP-send-buffer
AT+CIPCHECKSEQ Check if a specific segment is sent or not
AT+CIPCLOSE Close TCP/UDP connection
AT+CIFSR Get local IP address
AT+CIPMUX Set multiple connections mode
AT+CIPSERVER Configure as server
AT+CIPMODE Set transmission mode
AT+SAVETRANSLINK Save transparent transmission link to Flash
AT+CIPSTO Set timeout when ESP8266 runs as TCP server
AT+CIUPDATE Upgrade firmware through network
AT+PING Ping an IP address or hostname

Schematic Online Viewer


Tech Support

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