Metadata-Version: 2.1
Name: pyDE1
Version: 0.6.0
Summary: Controller for Decent Espresso DE1
Home-page: https://github.com/jeffsf/pyDE1
Author: Jeff Kletsky
Author-email: git-commits@allycomm.com
License: UNKNOWN
Project-URL: Bug Tracker, https://github.com/jeffsf/pyDE1/issues
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Framework :: AsyncIO
Classifier: Intended Audience :: Developers
Classifier: Topic :: Home Automation
Classifier: License :: OSI Approved :: GNU General Public License v3 (GPLv3)
Requires-Python: >=3.8
Description-Content-Type: text/markdown
License-File: LICENSE

# pyDE1

## License

Copyright © 2021 Jeff Kletsky. All Rights Reserved.

License for this software, part of the pyDE1 package, is granted under

GNU General Public License v3.0 only

SPDX-License-Identifier: GPL-3.0-only


## Overview

This represents work-in-progress to an API-first implementation of
core software for a controller for the DE1.

The extent of functionality is sufficient to upload profiles and pull
shots, flush the group, steam, and draw hot water through the API,
with stop-at-time, -volume, and -mass. Continuous updates of flow
parameters, and state transitions are provided over MQTT. Firmware
upload is supported, though not yet revealed in the API.

Profiles and real-time data are captured into a SQLite3 database 
that allows multiple, concurrent access. An example program 
is provided that generates legacy-style, "shot files" that 
are compatible with Visualizer and John Weiss' shot-plotting programs. 

A "worked example" is available at `examples/find_first_and_load.py` that

* Initializes and starts an MQTT listener, then, through the API
* Determines if a DE1 and scale are connected
* If not, connects to the first-found
* Waits until the DE1 is "ready" (self-initializes without API intervention)
* Uploads a profile
* Sets the stop-at-weight target and disables stop-at-time and stop-at-volume
* Optionally disconnects the DE1 and scale

The APIs are under semantic versioning. The REST-like, HTTP-transport
versions can be retrieved from `version` at the document root, and
also include the Python and package versions installed. Each of the
JSON-formatted, MQTT packets contains a `version` key:value for that
payload.

Consumers of these APIs should only need to understand high-level
actions, such as "Here is a profile blob, please load it." The
operations and choice of connectivity to the devices is "hidden"
behind the APIs.

## Revision History

See also CHANGELOG.md

* 2021-07-25 – 0.6.0 adds database store
* 2021-07-14 – 0.5.0, "worked example" description
* 2021-07-03 – Updated for release 0.4.0, see also CHANGELOG.md
* 2021-06-26 – Content and organizational updates for release 0.3.0
* 2021-06-22 – Updated for release 0.2.0
* 2021-06-11 – Updated for release 0.1.0
* 2021-06-08 – Initial release

## Support and Discussion

Support and discussion is active at DecentForum.com, on Discord in the
Decent Espresso server and, to some extent, on the Espresso
Aficianados server in the Manufacturers: decent channel. Support is,
unfortunately, ***not*** available through Decent Diaspora on
Basecamp.

Thanks to all that have been trying this out and providing valuable feedback!

See also
[https://github.com/jeffsf/pyDE1](https://github.com/jeffsf/pyDE1)
where the *alpha* branch is current.

## What's New

_**Please see CHANGELOG.md for more details**_

### New

A SQLite3 database now saves all profiles uploaded to the DE1, as well as 
capturing virtually all real-time data during all flow sequences, 
including a brief set of data from *before* the state transition.

Profiles are unique by the content of their "raw source" and also have 
a "fingerprint" that is common across all profiles that produce 
the same "program" for the DE1. Changing a profile's name alone 
does not change this fingerprint. Changing the frames in a profile 
without changing the name changes both the ID of the profile, 
as well as its fingerprint. These both are calculated using SHA1 
from the underlying data, so should be consistent across 
installs for the same source data or frame set. 

Profiles can also be searched by the customary metadata:

* Title
* Author
* Notes
* Beverage type
* Date added


`aiosqlite` and its dependencies are now required.

Legacy-style shot data can be extracted from the database by 
an application other that that which is running the DE1. 
Creating a Visualizer-compatible "file" for upload can be done 
in around 80-100 ms on a RPi 3B. If written to a physical file, 
it is also compatible with John Weiss' shot-plotting programs. 
See `pyDE1/shot_file/legacy.py` 

The database retains the last-known profile uploaded to the DE1. 
If a flow sequence beings prior to uploading a profile, it is used 
as the "most likely" profile and identified in the database 
with the `profile_assumed` flag.

**NB: The database needs to be manually initialized prior to use.**

One approach is

```
sudo -u <user> sqlite3 /var/lib/pyDE1/pyDE1.sqlite3 \
< path/to/pyDE1/src/pyDE1/database/schema/schema.001.sql 

```

The directory also needs to be writable by the user running the code 
as the database is set for [WAL mode](https://sqlite.org/wal.html) 
to permit concurrent access from multiple threads, processes and programs.

### Deprecated

`Profile.from_json_file()` as it is no longer needed with the API
able to upload profiles. If needed within the code base, read
the file, and pass to `Profile.from_json()` to ensure that
the profile source and signatures are properly updated.

`DE1._recorder_active` and the contents of `shot_file.py` 
have been superseded by database logging.


## Requirements

Python 3.8 or later.

Available through `pip`:

* `bleak`
* `aiologger`
* `aiosqlite`
* `asyncio-mqtt`
* `paho-mqtt`
* `requests`

An MQTT broker compatible with MQTT 5 clients, such as `mosquitto 2.0`
(see [below](#installing-mosquitto))

The Raspberry Pi version of Debian *Buster* ships with Python 3.7,
which does not support named `asyncio.Task()` The "walrus operator" is
also used.

Python 3.9 is expected to be part of Debian "next". Until that time,
https://github.com/pyenv/pyenv can be used to install a version of
your choice. On a RPi 3B, a complete build too under 15 minutes.

Development work is being done on *Buster* with Python 3.9.5 on a RPi 3B
at this time.

The `bleak` library is supported on macOS, Linux, and Windows. Some
development has also been done under macOS.

## Short-Term Priorities

* API to query profile database and load DE1 directly with a former profile
* Manage unexpected disconnects and reconnects
* Abort long-running actions, such as uploading firmware
* Daemonize and provide Debian-compatible service script


## Known Gaps

* Timeouts on certain locks and await actions
* Single-command read of the DE1 debug register
* Clean, descale, transport
* Clean up the imports
* More doc strings and typing
* Stand-alone documentation
* Quick-start guide

## Other Work

* Onboard, unattended sleep timeout with override
  (GUI or HA can provide complex "scheduler")
* Background firmware update
* MQTT will and MQTT 5 message expiry time


## Status — Alpha

This code is work in progress and is neither feature-complete nor fully tested.

Although most features are working, as described in Section 15 and
elsewhere of the GPLv3.0 `LICENSE`:

> THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 



## Some Older Notes of Explanatory Value

_**Please see CHANGELOG.md for newer details**_

### 0.2.0

#### Inbound Control and Query API

An inbound API has been provided using a REST-like interface over
HTTP. The API should be reasonably complete in its payload and method
definitions and comments are welcomed on its sufficiency and
completeness.

Both the inbound and outbound APIs run in separate *processes* to
reduce the load on the controller itself.

GET should be available for the registered resources. 
See, in `src/pyDE1/dispatcher`

* `resource.py` for the registered resources, and
* `mapping.py` for the elements they contain, the expected value types, 
  and how they nest.

`None` or `null` are often used to me "no value", such as for stop-at
limits. As a result, though similar, this is not an [RFC7368 JSON
Merge Patch](https://datatracker.ietf.org/doc/html/rfc7386).

In Python notation, `Optional[int]` means an `int` or `None`. Where
`float` is specified, a JSON value such as `20` is permitted.

GET presently returns "unreadable" values to be able to better show
the structure of the JSON. When a value is unreadable, `math.nan` is
used internally, which is output as the JSON `NaN` token.

GET also returns empty nodes to illustrate the structure of the
document. This can be controlled with the `PRUNE_EMPTY_NODES` variable
in `implementation.py`

Although PATCH has been implemented for most payloads, PUT is not yet
enabled. PUT will be the appropriate verb for`DE1_PROFILE` and
`DE1_FIRMWARE` as, at this time, in-place modification of these is not
supported. The API mechanism for starting a firmware upload as not
been determined, as it should be able to abort as it runs in the
background, as well as notify when complete. Profile upload is likely
to be similar, though it occurs on a much faster time scale.

> The Python `http.server` module is used. It is not appropriate for exposed use.
> 
> There is no security to the control and query API at this time.
> 
>  See further https://docs.python.org/3/library/http.server.html

It is likely that the server, itself, will be moved to a uWSGI (or similar) process.

With either the present HTTP implementation or a future uWSGI one, use
of a webserver, such as `nginx`, will be able to provide TLS,
authentication, and authorization, as well as a more
"production-ready" exposure.


#### Other Significant Changes

* `ShotSampleWithVolumeUpdates` (v1.1.0) adds `de1_time`. `de1_time`
  and `scale_time` are preferred over `arrival_time` as, in a future
  version, these will be estimates that remove some of the jitter
  relative to packet-arrival time.

* To be able to keep cached values of DE1 variables current, a
  read-back is requested on each write.

* `NoneSet` and `NONE_SET` added to some `enum.IntFlag` to provide
  clearer representations

* Although `is_read_once` and `is_stable` have been roughed in,
  optimizations using them have not been done

* Disabled reads of `CUUID.ReadFromMMR` as it returns the request
  itself (which is not easily distinguishable from the data
  read. These two interpret their `Length` field differently, making
  it difficult to determine if `5` is an unexpected value or if it was
  just that 6 words were requested to be read.

* Scaling on `MMR0x80LowAddr.TANK_WATER_THRESHOLD` was corrected.


### 0.1.0

#### Outbound API

An outbound API (notifications) is provided in a separate process. The
present implementation uses MQTT and provides timestamped,
source-identified, semantically versioned JSON payloads for:

* DE1
	* Connectivity
	* State updates
 	* Shot samples with accumulated volume
 	* Water levels
* Scale
 	* Connectivity
 	* Weight and flow updates
* Flow sequencer
 	* "Gate" clear and set
	  	* Sequence start
	  	* Flow begin
	  	* Expect drops
	  	* Exit preinfuse
	  	* Flow end
	  	* Flow-state exit
	  	* Last drops
	  	* Sequence complete
  	* Stop-at-time/volume/weight
  		* Enable, disable (with target)
  		* Trigger (with target and value at trigger)

An example subscriber is provided in `examples/monitor_delay.py`. On a
Raspberry Pi 3B, running Debian *Buster* and `mosquitto` 2.0 running
on `::`, median delays are under 10 ms from *arrival_time* of the
triggering event to delivery of the MQTT packet to the subscriber.

Packets are being sent with *retain* True, so that, for example, the
subscriber has the last-known DE1 state without having to wait for a
state change. Checking the payload's `arrival_time` is suggested to
determine if the data is fresh enough. The *will* feature of MQTT has
not yet been implemented.

A good introduction to MQTT and MQTT 5 can be found at HiveMQ:

* https://www.hivemq.com/mqtt-essentials/
* https://www.hivemq.com/blog/mqtt5-essentials-part1-introduction-to-mqtt-5/

One good thing about MQTT is that you can have as many subscribers as
you want without slowing down the controller. For example, you can
have a live view on your phone, live view on your desktop, log to
file, log to database, all at once.

#### Scan For And Use First DE1 And Skale Found

Though "WET" and needing to be "DRY", the first-found DE1 and Skale
will be used. The Scale class has already been designed to be able to
have each subclass indicate if it recognizes the advertisement. Once
DRY, the scanner should be able to return the proper scale from any of
the alternatives.

Refactoring of this is pending the formal release of
`BleakScanner.find_device_by_filter(filterfunc)` 
from [bleak PR#565](https://github.com/hbldh/bleak/pull/565)


## High Level Functionality

* Connect by address to DE1
* Read and decode BLE characteristics
* Encode and write BLE characteristics
* Read and decode MMR registers
* Encode and write MMR registers
* Upload firmware
* Parse JSON profile (v2) and upload
* Connect by address to SkaleII
* Scale processing for weight and flow, including period estimation
* Stop-at-time
* Stop-at-volume
* Stop-at-weight
* Enable/disable "shot" logging
* Outbound API over MQTT
* Basic connectivity tracking
* Bleutooth scanning
* Find and use first DE1 and Skale
* Inbound control and query API over HTTP
* Save profiles and real-time data into SQLite3 with concurrent access
* Provide legacy-style, "shot file" data for Miha Rekar's
  [Visualizer](https://visualizer.coffee)
  and John Weiss' shot-plotting code 

The main process runs under Python's native `asyncio` framework. There
are many tutorials out there that make asynchronous programming *look*
easy. "Hello world!" is always easy. For a better understanding, 
I found Lynn Root's *[asyncio: We Did It
Wrong](https://www.roguelynn.com/words/asyncio-we-did-it-wrong/)* to
be very insightful.


<a name="installing-mosquitto"></a>
## Installing Mosquitto 2.0

The example outbound API uses MQTT 5. If you don't already have a
local MQTT 5 broker configured, there are some public test servers
("brokers"), such as https://test.mosquitto.org/, that can let you try
things out quickly. A local broker is better from both from a security
standpoint and for delay. The preferred configuration is to have a
broker running on the same machine as this code on a loopback
interface. Unfortunately, the [`paho` library does not support Unix
domain sockets](https://github.com/eclipse/paho.mqtt.c/issues/864) at
this time.

The example outbound API does not use encryption as it runs over a
socket local to the host, the data is not considered "sensitive", and
there is no control over the DE1. Token-based authentication, such as
password, should be done over an encrypted channel if can be "snooped"
by others.

Mosquitto 2.0 is a MQTT broker that supports MQTT 5. Older
distributions only supply 1.x versions, such as 1.5.7 on Debian
*Buster.* Debian *Bullseye* is showing that it will support 2.0.10 at
this time.

Mosquitto 2.0 can be installed onto Debian systems without needing to
build from source using the [Mosquitto Debian
Repository](https://mosquitto.org/blog/2013/01/mosquitto-debian-repository/). The
usual caveats around making personal decisions about which sources you
trust apply.

You likely will want both `mosquitto` (the broker) and `mosquitto-clients`.

Installing on RPi will enable the `mosquitto.service` using
`/etc/mosquitto/mosquitto.conf`.  If you've used v1.x in the past, I'd
suggest reading [the release
announcement](https://mosquitto.org/blog/2020/12/version-2-0-0-released/)
as well as the notes on [migrating from 1.x to
2.0](https://mosquitto.org/documentation/migrating-to-2-0/)


## Notes

The code is littered with TODOs and personal notes. Ray may find his
name mentioned with some loose thoughts about changes. *These are
loose thoughts worthy of some future discussion, not blockers and not
direct requests!*


