Support sending MQTT messages via M118

Tools/mqttecho/README.md

@@ -0,0 +1,154 @@
+
+# Requirements
+
+- [Python](https://www.python.org/downloads/) - runs the demo script, `echo.py`, which runs broker and `echo` client
+    - [Paho](https://www.eclipse.org/paho/index.php?page=clients/python/index.php) - used to implement the `echo` MQTT client
+    - [Colorama](https://pypi.org/project/colorama/) - used to colorize log output of `echo.py`
+
+- [Mosquitto](https://mosquitto.org/download/) - MQTT broker used in the demo
+
+# Overview
+
+## Setup
+
+The demo has three components: the MQTT broker, the `echo` MQTT client and the RRF MQTT client.
+
+The RRF MQTT client publishes message sent via `M118` under a topic `topic-duet`.
+The `echo` MQTT client is subscribed to this topic, which retransmits the message under the topic `topic-echo`. Since the RRF MQTT client in turn is subscribed to this topic, it receives and displays the retransmitted message.
+
+## Broker Configuration
+
+Broker configuration can be found in [mosquitto.conf](./mosquitto.conf). This configuration:
+- disallows anonymous clients, allowing only clients with authentication credentials to connect
+- specifies the password file, [passwords.txt](./passwords.txt), whose contents are the allowed client usernames and the corresponding password hashes
+- runs the MQTT broker on a different port, 1884 instead of the typical 1883
+
+## Password File
+
+The clear text contents of the password file [passwords.txt](./passwords.txt) are as follows:
+
+```
+test-echo:test-echo-pswd
+test-duet:test-duet-pswd
+```
+
+Running the command `mosquitto_passwd -U passwords.txt` on the clear text contents will replace the password part (the text after the colon on each row) with its hash.
+
+The first row are the credentials for the `echo` client; the second are the credentials for the RRF MQTT client.
+
+
+# Running the Demo
+
+## Host
+
+Open a command line/terminal and `cd` into this directory, then run the command below.
+
+```
+python echo.py
+```
+
+Running the [GCode commands on RepRapFirmware](#reprapfirmware), a log similar to the following one should be seen.
+
+```
+1671016326: mosquitto version 2.0.15 starting
+1671016326: Config loaded from mosquitto.conf.
+1671016326: Opening ipv4 listen socket on port 1884.
+1671016326: Opening ipv6 listen socket on port 1884.
+1671016326: mosquitto version 2.0.15 running
+echo: connecting to 'localhost' on port '1884' as 'echo'...
+1671016327: New connection from ::1:39785 on port 1884.
+1671016327: New client connected from ::1:39785 as echo (p2, c1, k60, u'test-echo').
+1671016327: No will message specified.
+1671016327: Sending CONNACK to echo (0, 0)
+echo: connect succeeded, subscribing to topic 'topic-duet'...
+1671016327: Received SUBSCRIBE from echo
+1671016327:     topic-duet (QoS 0)
+1671016327: echo 0 topic-duet
+1671016327: Sending SUBACK to echo
+echo: subscribe succeeded, waiting for messages...
+1671016359: New connection from 192.168.10.125:60423 on port 1884.
+1671016359: New client connected from 192.168.10.125:60423 as duet (p2, c1, k400, u'test-duet').
+1671016359: No will message specified.
+1671016359: Sending CONNACK to duet (0, 0)
+1671016359: Received SUBSCRIBE from duet
+1671016359:     topic-echo (QoS 0)
+1671016359: duet 0 topic-echo
+1671016359: Sending SUBACK to duet
+1671016365: Received PUBLISH from duet (d0, q0, r0, m0, 'topic-duet', ... (12 bytes))
+1671016365: Sending PUBLISH to echo (d0, q0, r0, m0, 'topic-duet', ... (12 bytes))
+echo: received message with topic 'topic-duet': 'b'duet-message\n'', echoing...
+echo: echo succeeded
+1671016365: Received PUBLISH from echo (d0, q0, r0, m0, 'topic-echo', ... (12 bytes))
+1671016365: Sending PUBLISH to duet (d0, q0, r0, m0, 'topic-echo', ... (12 bytes))
+1671016372: Received DISCONNECT from duet
+1671016372: Client duet disconnected.
+
+```
+
+
+## RepRapFirmware
+
+The WiFi interface must be configured and enabled.
+
+### Enable debugging messages (optional)
+
+```
+M111 P2 S1
+```
+
+### Configure the MQTT client
+
+```
+M586.5 C"duet"
+M586.5 U"test-duet" K"test-duet-pswd"
+M586.5 P"topic-duet" D0 R0 Q0
+M586.5 S"topic-echo" Q0
+```
+
+- `C` - Client ID
+- `U`, `K` - Username and password ()
+- `S`, `Q` - Subcription topic and corresponding QOS
+- `P`, `D`, `R`, `Q` - Publish settings: topic, duplicate flag, retain flag, QOS
+### Enable the MQTT protocol
+
+```
+M586 P5 R1884 H192.168.10.244 S1
+```
+
+### Publish a message via M118
+
+```
+M118 P6 S"duet-message"
+```
+
+This message will be echoed back by the `echo` client, under topic `topic-echo`.
+Since the RRF MQTT client is subscribed to this topic, it should receive that message:
+
+```
+Received message from topic 'topic-echo': 'duet-message'
+```
+
+### Disable the MQTT Protocol
+
+```
+M586 P5 S0
+```
+# Scenarios
+
+
+1. MQTT protocol is enabled before `echo.py` can be started. This means the broker is not yet started when the RRF MQTT client attempts to connect.
+
+    - This should be ok, as the MQTT client will attempt reconnection automatically.
+
+2. The running `echo.py` is terminated while RRF MQTT client is connected.
+
+    - This should be ok, as the MQTT client will attempt reconnection automatically.
+
+3. MQTT protocol is configured and enabled before starting the network interface via `M552 S1`.
+
+    - This should be ok, the MQTT client will only attempt connection once the network interface is active.
+
+4. MQTT client is configured while connecting/connected.
+
+    - This is not ok, and should results in an error GCode result. Configuration is
+        only possible while the protocol is disabled.

Tools/mqttecho/echo.py

@@ -0,0 +1,66 @@
+# Runs the MQTT broker and echo client. See README.md for more information
+# about the demonstration this Python script is a part of.
+
+import paho.mqtt.client as mqtt
+import subprocess
+import threading
+import time
+
+from colorama import Fore
+from colorama import Style
+
+HOST = "localhost"
+PORT = 1884
+USERNAME = "test-echo"
+PASSWORD = "test-echo-pswd"
+CLIENT_ID = "echo"
+SUBSCRIBE_TOPIC = "topic-duet"
+PUBLISH_TOPIC = "topic-echo"
+
+def broker():
+    # Start the Mosquitto broker in verbose mode, using the config file.
+    subprocess.run(["mosquitto", "-v", "-c", "mosquitto.conf"])
+
+# The callback for when the client receives a CONNACK response from the server.
+def on_connect(client, userdata, flags, rc):
+    if rc == 0:
+        print(f"{Fore.YELLOW}echo: connect succeeded, subscribing to topic '{SUBSCRIBE_TOPIC}'...{Style.RESET_ALL}")
+        client.subscribe(SUBSCRIBE_TOPIC)
+    else:
+        print(f"{Fore.YELLOW}echo: connect failed, result code: {rc}{Style.RESET_ALL}")
+
+# The callback for when a PUBLISH message is received from the server.
+def on_message(client, userdata, msg):
+    print(f"{Fore.YELLOW}echo: received message with topic '{msg.topic}': '{msg.payload}', echoing... {Style.RESET_ALL}")
+    res = client.publish(PUBLISH_TOPIC, msg.payload, msg.qos, msg.retain)
+
+    if res[0] == 0:
+        print(f"{Fore.YELLOW}echo: echo succeeded {Style.RESET_ALL}")
+    else:
+        print(f"{Fore.YELLOW}echo: echo failed, result code: ${res[0]}{Style.RESET_ALL}")
+
+def on_subscribe(client, userdata, mid, granted_qos):
+    print(f"{Fore.YELLOW}echo: subscribe succeeded, waiting for messages...{Style.RESET_ALL}")
+
+def echo():
+    client = mqtt.Client(CLIENT_ID)
+    client.username_pw_set(USERNAME, PASSWORD)
+
+    client.on_connect = on_connect
+    client.on_message = on_message
+    client.on_subscribe = on_subscribe
+
+    print(f"{Fore.YELLOW}echo: connecting to '{HOST}' on port '{PORT}' as '{CLIENT_ID}'{Style.RESET_ALL}...")
+    client.connect(HOST, PORT)
+    client.loop_forever()
+
+def main():
+    broker_thread = threading.Thread(target=broker)
+    echo_thread = threading.Thread(target=echo)
+
+    broker_thread.start()
+    time.sleep(1) # make sure the broker is up
+    echo_thread.start()
+
+if __name__ == '__main__':
+    main()

Tools/mqttecho/mosquitto.conf

@@ -0,0 +1,3 @@
+allow_anonymous false
+password_file passwords.txt
+listener 1884

Tools/mqttecho/passwords.txt

@@ -0,0 +1,2 @@
+test-echo:$7$101$cZHHLpYfn5d4WH/6$NZYAZYWAMAoFyFpfGKHAUSCu/x9czfaLg+xO5WIaIOy7ap74srHX9dpf62zsKaTRdVbRViTqV3zvYsZXDmwplg==
+test-duet:$7$101$bjDUJ7R4hobUf1Ph$b8zrtkAb9HxZR30HnGnV4NSGAqF5kD8whXepqlSMHRqZRa6vzuQ66XyjUuSrE4khm3+O4PdHA2xQ/WGEz74zHw==

src/Config/Pins.h

@@ -195,6 +195,10 @@
 # define SUPPORT_TELNET			HAS_NETWORKING
 #endif
 
+#ifndef SUPPORT_MQTT
+# define SUPPORT_MQTT			HAS_NETWORKING
+#endif
+
 #ifndef SUPPORT_MULTICAST_DISCOVERY
 # define SUPPORT_MULTICAST_DISCOVERY	0
 #endif

src/Config/Pins_Duet3Mini.h

@@ -62,6 +62,7 @@ constexpr uint32_t IAP_IMAGE_START = 0x20038000;
 #define SUPPORT_OBJECT_MODEL	1
 #define SUPPORT_FTP				1
 #define SUPPORT_TELNET			1
+#define SUPPORT_MQTT			1
 #define SUPPORT_ASYNC_MOVES		1
 #define SUPPORT_PROBE_POINTS_FILE	1