ASCOM Alpaca Server for ESP32 based devices

This is an ASCOM Alpaca Server implementation for ESP32. The following devices are supported:

• Cover Calibrator V1
• Observing Conditions V1
• Switch V2
• Focuser V3

This library is more or less a new implementation. But it's primary based on the great ideas and work of:

• https://github.com/agnunez/AlpacaServerESP32.git
• https://github.com/elenhinan/ESPAscomAlpacaServer

Great and important Libraries used in this implementation:

• Async WebServer for ESP
  • https://registry.platformio.org/libraries/mathieucarbou/ESP%20Async%20WebServer
• Json
  • https://arduinojson.org/
• Upload over the air
  • https://github.com/ayushsharma82/ElegantOTA

Motivation

My primary motivation was:

• To have a state of the art compact and robust platform for the rework of my ESP32 based devices with propritary network protocols and .NET based ASCOM drivers.
• Learn and understand ASCOM Alpaca API
• Work with embedded systems and web technologies
  
  

Features

• Easy to use platform for Alpaca Self Contained Device & Driver

• Templates for CoverCalibrator, Switch, ObservingConditions and Focuser

• Support ASCOM auto discovery

• Optimized for ESP32 (ESP286 not supported!)

• Improved robustness, logging, error handling and debugging

• Device service counter for diagnosis

• Published as library

• Several and different ASCOM devices on one ESP32 possible

• Several client connections per device supported

• Pass ASCOM Conform Universal validation with zero errors and zerro issues (ConformU 3.0.0)

• Addapted for ArduinoJason V7

• Test with N.I.N.A 3.1 HF2 - with ASCOM Alpaca Discovery (https://nighttime-imaging.eu/)

• Suported ASCOM devices:

  • CoverCalibrator, ObservingConditions, Switch, Focuser

• Example Applications

  • CoverCalibrator.h, CoverCalibrator.cpp
  • ObservingConditions.h, ObservingConditions.cpp
  • Switch.h, Switch.cpp
  • Focuser.h, Focuser.cpp

• Support of optional ASCOM Methods: action, commandblind, commandbool, commandstring

  • Full implementation for CoverCalibrator

• Serial and network based logging using SLog: "https://github.com/npeter/SLog"

• Manage persistant device data

  • stored with Setup/button "Save" in LittleFS:/settins.json
  • read (only) at device boot

• Configure persistant data via dynamicaly created webpages (based on the ideas from (https://github.com/elenhinan/ESPAscomAlpacaServer))

- Buttons: - Refresh: Refresh web page with current device data - Update: Write web page data to device - Save: Store device data to LittleFS:/settings.json - Reset: Reset device after 10 seconds - Tabs: - Server: Server settings - Dynamic created device specific settings tabs

Remarks

• For this project "platformio" (https://platformio.org/) is used as development system.
  
  

Example platformio.ini

[env]
platform = espressif32
framework = arduino
monitor_speed = 115200
board_build.filesystem = littlefs

lib_deps = https://github.com/npeter/ESP32AlpacaDevices2

[env:wemos_d1_mini32]
board = wemos_d1_mini32
build_flags=
    -D ELEGANTOTA_USE_ASYNC_WEBSERVER=1
    -D WEMOS_D1_MINI32

[env:lolin_s2_mini]
board = lolin_s2_mini
monitor_port = COM3
upload_speed = 921600
build_flags=
    -D ELEGANTOTA_USE_ASYNC_WEBSERVER=1
    -D ARDUINO_USB_CDC_ON_BOOT=1
    -D LOLIN_S2_MINI

ESP32AlpacaDevices library dependencies: (see library.json)

...
"dependencies": [
    {
        "owner": "mathieucarbou",
        "name": "ESPAsyncWebServer",
        "version": "^3.3.11",
        "platforms": [
            "espressif8266",
            "espressif32"
        ]
    },
    {
        "owner": "bblanchon",
        "name": "ArduinoJson",
        "version": "^7.0.2"
    },
    {
        "owner": "ayushsharma82",
        "name": "ElegantOTA",
        "version": "^3.1.6"
    },
    {
        "name": "SLog",
        "version": "https://github.com/npeter/SLog"
    }
],
...

Webpage data

• Webpage data has to be stored in the LittleFS - Filesystem of the ESP32

  • platformio/Build Filesystem image

    VSCode example output:
    Building FS image from 'data' directory to .pio\build\wemos_d1_mini32\littlefs.bin /www/css/bootstrap.min.css.gz /www/css/jquery-ui.min.css.gz /www/css/theme.css /www/js/bootstrap.min.js.gz /www/js/jquery-ui.min.js.gz /www/js/jquery.min.js.gz /www/js/jsonFormer.jquery.js /www/setup.html

  • platformio/Upload Filesystem Image
    

    VSCode example output:
    Building in release mode
    Building FS image from 'data' directory to .pio\build\wemos_d1_mini32\littlefs.bin
    /www/css/bootstrap.min.css.gz
    /www/css/jquery-ui.min.css.gz
    /www/css/theme.css
    /www/js/bootstrap.min.js.gz
    /www/js/jquery-ui.min.js.gz
    /www/js/jquery.min.js.gz
    /www/js/jsonFormer.jquery.js
    /www/setup.html
    Looking for upload port...
    Auto-detected: COM5
    Uploading .pio\build\wemos_d1_mini32\littlefs.bin
    esptool.py v4.7.5
    Serial port COM5
    Connecting.......
    Chip is ESP32-D0WDQ6 (revision v1.0)
    Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
    Crystal is 40MHz
    MAC: c8:c9:a3:cb:7c:d4
    Uploading stub...
    Running stub...
    Stub running...
    Changing baud rate to 460800
    Changed.
    Configuring flash size...
    Auto-detected Flash size: 4MB
    Flash will be erased from 0x00290000 to 0x003effff...
    Compressed 1441792 bytes to 152944...
    Writing at 0x00290000... (10 %)
    Writing at 0x002e7915... (20 %)
    Writing at 0x002ebc14... (30 %)
    Writing at 0x002f2968... (40 %)
    Writing at 0x002f6f46... (50 %)
    Writing at 0x002faf41... (60 %)
    Writing at 0x002fef3c... (70 %)
    Writing at 0x00302f37... (80 %)
    Writing at 0x00307639... (90 %)
    Writing at 0x0030b5f2... (100 %)
    Wrote 1441792 bytes (152944 compressed) at 0x00290000 in 9.5 seconds (effective 1214.9 kbit/s)...
    Hash of data verified.
    Leaving...
    Hard resetting via RTS pin...
    

Usage

• Let your class inherit the relevant AscomDevice-derived class (e.c. AscomSwitch, AscomCoverCalibrator, AscomObservingConditions, AscomFocuser)
• Implement all pure virtual functions
• Implement all your device/hardware specific functions
• Adapt AlpacaReadJson/AlpacaWriteJson if needed
• Implement main.cpp/setup() and loop() (see example below)
• See also demo application .\Examples*

ESP32AlpacaDevices class diagram

Demo Application: Alpaca Discovery Map generated with **Conform Universal **

Example main.cpp (see ./Examples/*.** for more details)

The following code block shows the prinziple setup and loop

#include <SLog.h>
#include <AlpacaDebug.h>
#include <AlpacaServer.h>
#include <CoverCalibrator.h>
#include <Switch.h>
...

// Create CoverCalibrator, SwitchDevice and AlpacaServer
CoverCalibrator coverCalibrator;
Switch switchDevice;  
AlpacaServer alpaca_server("your server name", "your manufacture", "your version", "your location");
...
void setup()
{
    // Setup logging 
    g_Slog.Begin(Serial, 115200);
    SLOG_INFO_PRINTF("BigPet ESP32ALPACADeviceDemo started ...\n");

    // Setup WiFi
    ... 

    // Setup ESP32 Alpaca Server and Devices
    // 1. Init AlpacaServer
    alpaca_server.Begin();

    // 2. Init and add devices
    coverCalibrator.Begin();
    switch.Begin();
    alpaca_server.AddDevice(&coverCalibrator);
    alpaca_server.AddDevice(&switchDevice);

    // 3. Finalize AlpacaServer 
    alpaca_server.RegisterCallbacks();
    alpaca_server.LoadSettings();
    ...

    g_Slog.SetLvlMsk(SLOG_WARNING);
    g_Slog.SetEnableSerial(true);
    ...
}

void loop()
{
    ...
    alpaca_server.Loop();
    coverCalibrator.Loop();
    switchDevice.Loop();
    ...
    delay(50);
}

Useful Links

• ASCOM Alpaca API
• ASCOM Platform Developer Help
• ASCOM Documentation Center
• platformio
• ArduinoJson
  
  

Open Topics

• Concept for AlpacaConfig.h
• Test device specific interface with real device implementation
  • Already done for
    • CoverCalibrator CoFlat
    • Focuser MoFo4
• Connection watch dog
  • if no request for a certain time (ALPACA_CLIENT_CONNECTION_TIMEOUT_SEC)
  • impliziet device specific disconnect