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-# Details about used MQTT messages
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+# Details about used MQTT messages
+
+## Topic lists
+- [`actuator`](#actuator)
+    - [`actuator/pump`](#actuatorpump)
+    - [`actuator/focus`](#actuatorfocus)
+- [`imager/image`](#imagerimage)
+- [`segmenter/segment`](#segmentersegment)
+- [`status`](#status)
+    - [`status/pump`](#statuspump)
+    - [`status/focus`](#statusfocus)
+    - [`status/imager`](#statusimager)
+    - [`status/segmenter`](#statussegmenter)
+    - [`status/segmenter/name`](#statussegmentername)
+    - [`status/segmenter/object_id`](#statussegmenterobject_id)
+    - [`status/segmenter/metric`](#statussegmentermetric)
+
+
+
+## Topic details
+### `actuator`
+#### `actuator/pump`
+Control the movement of the pump. The message is a JSON object:
+```json
+{
+  "action": "move",
+  "direction": "FORWARD",
+  "volume": 10,
+  "flowrate": 1
+}
+```
+This messages make the pump move 10mL forward at 1mL/min.
+
+Another supported message is:
+```json
+{
+  "action": "stop"
+}
+```
+
+- Receive only
+
+#### `actuator/focus`
+Control of the focus stage. The message is a JSON object, speed is optional:
+```json
+{
+  "action": "move",
+  "direction": "UP",
+  "distance": 0.26,
+  "speed": 1
+}
+```
+
+This message makes the stage move up by 10mm.
+
+Another supported message is:
+```json
+{
+  "action": "stop"
+}
+```
+
+- Receive only
+
+
+### `imager/image`
+This topic controls the camera and capture. The message allowed is a JSON message:
+```json
+{
+  "action": "image",
+  "sleep": 5,
+  "volume": 1,
+  "nb_frame": 200
+}
+```
+
+Sleep in seconds and volume in mL.
+
+This topic can also receive a config update message:
+```json
+{
+  "action": "config",
+  "config": {...}
+}
+```
+
+A camera settings message can also be received here. The fields `iso` and `shutter_speed` are optionals:
+```json
+{
+  "action": "settings",
+  "iso": 100,
+  "shutter_speed": 40
+}
+```
+
+- Receive only
+
+### `segmenter/segment`
+This topic controls the segmentation process. The message is a JSON object:
+```json
+{
+  "action": "segment"
+}
+```
+
+`action` can also be `stop`.
+
+- Receive only
+
+### `status`
+This high-level topic is used to send information to the Node-Red process. There is no publication or receive at this level.
+
+#### `status/pump`
+State of the pump. It's a JSON object with:
+```json
+{
+  "status": "Started",
+  "duration": 25
+}
+```
+
+Duration is a best guess estimate. It should not be used to control the other events. If you want to wait for a movement to finish, the best thing to do is to wait for the message `Done`.
+
+Status can be `Started`, `Ready`, `Done`, `Interrupted`, `Error`, `Dead`.
+
+- Publish only
+
+#### `status/focus`
+State of the focus stage. It's a JSON object with:
+```json
+{
+  "status": "Started",
+  "duration": 25
+}
+```
+
+Duration is a best guess estimate. It should not be used to control the other events. If you want to wait for a movement to finish, the best thing to do is to wait for the message `Done`.
+
+Status is one of `Started`, `Ready`, `Done`, `Interrupted`, `Error`, `Dead`.
+
+- Publish only
+
+#### `status/imager`
+State of the imager. It's a JSON object with:
+```json
+{
+  "status": "Started",
+  "time_left": 25
+}
+```
+
+Status is one of `Started`, `Ready`, `Completed` or `12_11_15_0.1.jpg has been imaged`.
+
+- Publish only
+
+#### `status/segmenter`
+Status of the segmentation. It's a JSON object with:
+```json
+{
+  "status": "Started",
+}
+```
+
+`status` is one of `Started`, `Done`, `Interrupted`, `Busy`, `Ready` or `Dead`.
+
+- Publish only
+
+#### `status/segmenter/object_id`
+```json
+{
+  "object_id": "13449"
+}
+```
+
+#### `status/segmenter/metric`
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