Worked out of the box. I do wish the headers came pre-soldered. I soldered myself and have down so before. Made sure they were clean before plugging in, after power on screen doesn't work. Appears the display can't handle much heat.

Nice board and with OLED built on. Came with loaded "Hello World!" so you can plug it in to a micro-USB immediately and see it is working. Can run up to 160MHz and 32bit processor -- incredibly fast when you need it. Separate CPU for processing and for OLED that do not detract from each other too (a change from older designs). Datasheets and manuals available on-line and user groups support and BLOGs out on the net are very helpful. .

What you can do with this product is limited only by your imagination. (Some programming required.) It can turn on a light when it sees your Phone connect to your WiFi network. It can monitor the stock market and turn a light green when the market is up, or red when the market is down. It can be controlled by smart home devices like Alexa. It can monitor temperatures and send the data to a central server for graphing. It can control a LED strip, making the lights respond to the music.

It is a tiny little computer that has WiFi. It can connect to the Internet (or just your local network) and talk many different protocols (HTTP, WebSockets, MTTQ, Email, Slack, etc.) You can also connect it to any electronic hardware (NeoPixels, OneWire Temperature sensors, Passive Infrared sensors, Switches, etc). This category of product is called "Internet Of Things" (IOT). Unlike many IOT devices, this is just hardware. No need to rely on someone else for a subscription service.

Pro:
- It's tiny: It's even smaller than a typical USB flash drive. You could hide several in a pack of gum.
- About 10x more powerful than an Arduino Uno, but half the price!
- If you need more power, there are bigger and better versions: ESP32 Version and LoRa Version
- Can run FreeRTOS, which just got a huge boost with deep AWS Cloud integration.
- Can reflash over USB (no need to push a button for programming mode) or WiFi (if you include the right library.)
- can run off a LiPo battery, or any USB wall wart or most any USB battery pack.

Con:
- Not a lot of documentation in English. That's fine, because it's supported by Arduino IDE and PlatformIO (in next release). I highly recommend the latter.
- More complex than a typical Arduino, so may not be the best starter device.

(Another review said there was no Pinout documentation, but I saw it was now posted to the Heltec website. It even included clear instructions in English on which pins were reserved by the OLED display.)

As others have stated, it's a little tricky to get going considering there's no documentation. Uploading a sketch follows the typical "NodeMCU/ESP-23E" guides. The OLED:

- Used Adafruit SSD1306 Library
- Loaded 128x32_i2c example sketch
- Set OLED_RESET = 16

After a bit of Googling it did come to life - I never did get the board manager to find the WIFI_Kit_8 so as the previous post said, use the generic ESP8266 and it works fine.