This is a Java class library that wraps communication functionalty of the ESP8266 AT command firmware. The ESP8266 class implements the capability by abstracting communication away from the serial port. The constructor takes a Java InputStream and OutputStream. The ./samples directory contains examples that demonstrate calling the library from a Windows/Mac/Linux operating system with the very good jSerialComm serial port library. The ./boards directory demonstrate using this library on embedded boards, like the Raspberry Pi, with no operating system.
This library has been coded and tested against the AI Thinker revision 018 of the AT command firmware. This document was originally written in Chinese and is translated here in English for convenience. I wrote this library against said version because this was the revision installed on my ESP-01 boards (purchased several years ago). I did not want to have to flash upgrades, etc.
- Java JDK (my version was
openjdk 11.0.1-redhat 2018-10-16 LTS, but earlier versions would probably work) - A USB TTL serial cable like this one from Adafruit
- An ESP-01 like this one
- A 3.3v power supply or alternative to get 5v down to somewhere between 3.3 and 4v @ 250ma
- In my example, I use the voltage drop of a standard germanium diode (0.7v) to get voltage in range, and connected it to the supply from the USB cable (which is capable of 500 ma). Note: the specs say ESP-01 voltage requirement is 3.3v - I take no responsibility if this unregulated overvolt technique burns out your board. It works for mine.
To run the operating system specific example (tested on Windows 10 but should work on OSX and Linux):
- Clone the repo
- Connect TTL cable to ESP-01 like this:
+------------+ +------------------------------+
| | | |
+-----------+ +---->|-----+----)|----+ | | +-------------+ |
| CP2012 | | 1N4148 100 mfd | | | | ESP-01 | |
| | | | | +-+ TX GND +---|' |
| +5v Red +---- | | | | |
| | | +----+ CH_PD GPIO2 + |
| Gnd Black +------------------+-------+ | | | | ESP-01 top view
| | | | + RST GPIO0 + | Antenna on this side
| Tx Green +------------+ __ | | | |
| | | ' +----+ VCC RX +----+ |
| Rx White +----+ | | | | |
| | | | +-------------+ | |
+-----------+ | | | |
| +---------------------------------------+ |
| |
+---------------------------------------------------------+
- Change constants within
./samples/os/src/main/java/Main.javaaccording to comments to match your wifi environment. - Change directory to
./samples/os gradlew run
- Mux mode is not yet supported.
- TCP server mode is not supported.