HiLetgo 2pcs ESP8266 NodeMCU CP2102 ESP-12E Development Board (Wi-Fi, USB) - Arduino Compatible, 1MB RAM, 80MHz CPU, 1M Flash, 2 Boards

Complete project description follows. I'm using the NodeMCU as a web server and it works great. It was a struggle to find example code that actually connects outside my local area network but I found some. Also had to learn the rudiments of HTML. Only issue is it seems to need to be restarted every 4 or 5 days. Since I'm going to leave it in a remote location I'll put some code in the MEGA that sits right next to it to restart the NodeMCU every couple days, by pulling the RST pin low.Green Pond Bridge Boat ClearanceAt ‘very low tide’ the clearance under Green Pond Bridge in Cape Cod is 6’6” or less and that is too low for the boat I use. The tide charts for Falmouth, MA are theoretical and can vary as much as 18” from what is actually happening at the bridge. This system monitors the clearance and transmits the information on the internet.All of these parts were purchased from Amazon.TransmitterAn (Arduino) Elegoo UNO R3 board is connected to an Elegoo HC-SR04 Ultrasonic Distance Sensor. The UNO and the sensor calculate the distance from a fixed dock to the sea level, then transmit that data using a MakerFocus NRF24L01 Wireless Transceiver to the Receiver described below. The Transmitter sits on the end of a dock where there is no power, so the UNO, Transceiver and Distance Sensor are powered by the energyShield 2. This battery has special capabilities – it wakes everything up every 15 minutes. The system takes a couple readings of the distance to the water then transmits that data, then the battery shuts it all off. The data transmitted includes information from the battery – time, date, and voltage.I have been testing this unit at home (in Dallas) and it has been operating outside, for about 20 days. Based on battery drain it looks like it will operate for about 4-5 months before it needs a recharge. When the temperature drops below zero the system still works fine but the voltage reported in the battery seems low.All of this is housed in a plastic box printed for the purpose with a FlashForge 3d Printer Creator Pro, using eSun White ABS+ filamentPicture below.ReceiverAn (Arduino) Elegoo MEGA 2560 R3 is connected to another NRF24 Transceiver to receive the data. The MEGA does the math to convert the distance from the dock to the water, to the bridge clearance. Then the information is displayed on an Elegoo UNO R3 Touch Screen (that also works fine on the Mega).Picture below. A small plastic frame for the Receiver was also printed on the 3d printerWeb ServerFinally, the information in the MEGA is transmitted over a serial bus to a Hiletgo ESP8266 NodeMCU ESP-12E Internet WIFI Development Board (Also operates using Arduino IDE programming). This board is connected to the MEGA via the XCSOURCE Logic Level Converter and powered by a UCEC MB102 Breadboard Power Supply Module. All mounted on an Elegoo Breadboard. The ESP8266 is programmed to be a web server. It connects to the internet through the modem/router provided by AT&T.Picture of my cell phone below.

Followed instructions and done what I wanted to do not bad price for two. Would buy again if had a need for

Item as described, well packed.This brand does well, in my experience.

The ESP8266 boards are awesome! These are more powerful than the original arduino boards with built in wifi capabilities. There are numerous projects that can be quickly set up for IOT experimenting and prototyping. Using the Arduino IDE, the board profiles can be downloaded and set up in the IDE using the Boards Manager and from there the Arduino IDE is all you need to do development on these!Below is the output from the example application provided in the Arduino IDE for testing a few of the board's API calls:ESP starting.system_get_time(): 64235system_get_rst_info() reset reason: REASON_EXT_SYS_RSTsystem_get_free_heap_size(): 49944system_get_os_print(): 0system_get_os_print(): 1system_get_chip_id(): 0x75D9F1system_get_sdk_version(): 3.0.0-dev(c0f7b44)system_get_boot_version(): 31system_get_userbin_addr(): 0x0system_get_boot_mode(): SYS_BOOT_NORMAL_MODEsystem_get_cpu_freq(): 160system_get_flash_size_map(): FLASH_SIZE_32M_MAP_512_512wifi_get_opmode(): 1 - STATION_MODEwifi_get_opmode_default(): 1 - STATION_MODEwifi_get_broadcast_if(): 1SoftAP Configuration--------------------ssid: TestAPpassword: testtesttestssid_len: 6channel: 1authmode: AUTH_WPA2_PSKssid_hidden: 0max_connection: 4beacon_interval: 100ms--------------------

This is an edited review. Initially I rated this board with one star because I was not able to connect it to my computer. After I wrote my disappointed review, I tried some more different USB cables that I had in the house. With the 4th cable I was finally able to get the board to work. Of course, the first three were charging cables, without data wires!!! (I noticed several reviews describing complaints that these boards are not recognized when connected through a USB cable and I guess other people made the same mistake.)I took one star off my final rating because a couple of pins were bent on one of the two boards I purchased. Both boards work fine. As a side note, Arduino IDE is slow to load sketches on the board. Micropython is much faster but a little more difficult to get started with.

I've used several of these NODEMCU board now (from several manufacturers) from several different vendors. The HiLetGo boards are by far the most reliable, with one serious caveat: They are the V2 versions of the NODEMCU, and have a different form factor than the newer V3 NODEMCU boards. (NODEMCU V3 boards are a few millimeters wider than V2 boards). This only matters if you intend to mount the board on a base-board (effectively, a breakout board)... all of the NODEMCU base-boards I've seen are for V3 NODEMCU's.Form factor aside, I've have great luck with the Hiletgo versions of these boards. Downloads at full speed always seem to work, and they never seem to barf with the dreaded "espcomm sync failed" error.If you have any Arduino skills, these are *great* boards. I (who have lots of programming experience, but close to zero web-coding experience) was able to use one of these boards as the brain of an internet-enabled, web-accessible garage door manager.I highly recommend the Hiletgo version of the NODEMCU boards. Hiletgo: if you're reading this, please release a NODEMCU V3 version of this board. :-)