esp-vt100-firmware

ESP8266 Remote Terminal project

This project is based on SpriteTM's esphttpd and libesphttpd, forked by MightyPork to MightyPork/esphttpd and MightyPork/libesphttpd respectively.

Those forks include improvements not yet available upstream.

Goals

This project aims to be a wireless terminal emulator that'll work with the likes of Arduino, AVR, PIC, STM8, STM32, mbed etc, anything with UART, even your USB-serial dongle will work.

Connect it to the master device via UART and use the terminal on the built-in web page for debug logging, remote control etc. It works like a simple LCD screen, in a way.

It lets you make simple UI (manipulating the screen with ANSI sequences) and receive input from buttons on the webpage (and keyboard on PC). Touch input is planned as well.

The screen size is adjustable up to 25x80 (via a special control sequence) and uses 16 standard colors (8 dark and 8 bright).

Project status

Almost finished, still possibly buggy, but it looks promising. Most of the features are there now.

• We have a working 2-way terminal (UART->ESP->Browser and vice versa) with real-time update via websocket.

  This means that what you type in the browser is sent to UART0 and what's received on UART0 is processed by the ANSI parser and applied to the internal screen buffer. You'll also immediately see the changes in your browser. There's a filter in the way that discards garbage characters (like unicode and most ASCII outside 32-126).

  For a quick test, try connecting the UART0 Rx and Tx with a piece of wire to make a loopback interface. NOTE: Use the bare module, not something like LoLin or NodeMCU with a FTDI, it'll interfere. You should then directly see what you type & can even try some ANSI sequences, right from the browser.

• All ANSI sequences that make sense, as well as control codes like Backspace and CR / LF are implemented. Set colors with your usual \e[31;1m etc (see Wikipedia). \e is the ASCII code 27 (ESC).

  Arrow keys generate ANSI sequences, ESC sends literal ASCII code 27 etc. Almost everything can be input straight from the browser.

• To resize the screen, send \e]W<rows>;<cols>\a (it's an OSC code, terminated by ST).

• Buttons pressed in the browser UI send ASCII codes 1..5. Mouse clicks also send events to the server, but currently don't generate any output in the terminal, I still hadn't decided on the best encoding.

• By tapping the header on the terminal page, you'll open the WiFi config page. It's in essence the esphttpd's wifi config page, but re-styled and much improved. You can set AP SSID, channel, see the IP address etc right there.

Development

Installation for development

• Clone this project with --recursive, or afterwards run git submodule init and git submodule update.

• Install esp-open-sdk and build it with make toolchain esptool libhal STANDALONE=n.

  Make sure the xtensa-lx106-elf/bin folder is on $PATH.

• Install esptool (it's in the Arch community repo and on AUR, too)

• Set up udev rules so you have access to ttyUSB0 without root, eg:

  KERNEL=="tty[A-Z]*[0-9]*", GROUP="uucp", MODE="0666"
  

• Install Ragel if you wish to make modifications to the parser. If not, comment out it's call in build_parser.sh. The .rl file is the actual source, the .c is generated.

• Install Ruby and then the sass package with gem install sass (or try some other implementation, such as sassc)

• Get the IoT SDK from one of:

  ESP8266_NONOS_SDK_V2.0.0_16_08_10.zip:
    wget --content-disposition "http://bbs.espressif.com/download/file.php?id=1690"
  ESP8266_NONOS_SDK_V2.0.0_16_07_19.zip:
    wget --content-disposition "http://bbs.espressif.com/download/file.php?id=1613"
  ESP8266_NONOS_SDK_V1.5.4_16_05_20.zip:
    wget --content-disposition "http://bbs.espressif.com/download/file.php?id=1469"
  ESP8266_NONOS_SDK_V1.5.3_16_04_18.zip:
    wget --content-disposition "http://bbs.espressif.com/download/file.php?id=1361"
  ESP8266_NONOS_SDK_V1.5.2_16_01_29.zip:
    wget --content-disposition "http://bbs.espressif.com/download/file.php?id=1079"
  

  It's tested with 1.5.2, 2.0.0 won't work without adjusting the build scripts. Any 1.5.x could be fine.

  The esp-open-sdk Makefile could also download this for you with the right flags.

• Make sure your esphttpdconfig.mk is set up properly - link to the SDK etc.

Web resources

The web resources are in html_orig. To prepare for a build, run build_web.sh, which packs them and copies over to html. The compression and minification is handled by scripts in libesphttpd, specifically it runs yuicompressor on js and css and gzip or heatshrink on the other files. The html folder is then embedded in the firmware image.

It's kind of tricky to develop the web resources locally; you might want to try the "split image" Makefile option, then you can flash just the html portion with make htmlflash. I haven't tried this.

Flashing

The Makefile should automatically build the parser and web resources for you when you run make. Sometimes it does not, particularly with make -B. Try just plain make. You can always run those build scripts manually, too.

To flash, just run make flash.