Updated README and improved multimonitor support

README.md

@@ -1,7 +1,139 @@
-# ddc-mqtt
+# ddc-mqtt - A simple software Display Input switch for DDC-supporting monitors
 
-Setup:
+[!["Buy Me A Coffee"](https://www.buymeacoffee.com/assets/img/custom_images/orange_img.png)](https://www.buymeacoffee.com/moimartb)
 
-0. Connect a device where to run this to a DDC enabled port of your monitor— I use a raspberry pi with a GN95C Samsung display
+- Do you have a displays with multiple inputs?
-1. create a config.yml (copy it from rename_to_config.yml) for your mqtt credentials and monitor setup (Use ddcutil to get inputs and codes)
+- Would you like to be able to switch inputs without the need of meddling with clunky OSD menus and akwardly-positioned control 'nipples'?
-2. docker-compose up -d
+- Does this happen to you even with fancy, expensive displays like the Neo G9 line from Samsung? 
+- Can you imagine KVM scenarios based on home assistant scenarios?
+
+Then this software is for you!!!
+
+You only need a Linux machine connected to the display, a bit of knowledge on your monitor's support of DDC capabilities and this will 
+create a device for your 
+
+## Display's DDC capabilities
+
+First of all, you'd need some info about your display about DDC capabilities wrt display inputs. You'd need the *ddcutil* tool to figure
+things out. For example: this is what my G95NC Samsung Neo G9 Reports:
+
+```
+$ ddcutil capabilities
+Model: FALCON
+MCCS version: 2.0
+Commands:
+   Op Code: 01 (VCP Request)
+   Op Code: 02 (VCP Response)
+   Op Code: 03 (VCP Set)
+   Op Code: 07 (Timing Request)
+   Op Code: 0C (Save Settings)
+   Op Code: E3 (Capabilities Reply)
+   Op Code: F3 (Capabilities Request)
+VCP Features:
+   Feature: 02 (New control value)
+   Feature: 04 (Restore factory defaults)
+   Feature: 05 (Restore factory brightness/contrast defaults)
+   Feature: 08 (Restore color defaults)
+   Feature: 10 (Brightness)
+   Feature: 12 (Contrast)
+   Feature: 14 (Select color preset)
+      Values:
+         05: 6500 K
+         08: 9300 K
+         0b: User 1
+         0c: User 2
+   Feature: 16 (Video gain: Red)
+   Feature: 18 (Video gain: Green)
+   Feature: 1A (Video gain: Blue)
+   Feature: 52 (Active control)
+   Feature: 60 (Input Source)
+      Values:
+         01: VGA-1
+         03: DVI-1
+         04: DVI-2
+         11: HDMI-1
+         12: HDMI-2
+         0f: DisplayPort-1
+         10: DisplayPort-2
+   Feature: 62 (Audio speaker volume)
+   Feature: 8D (Audio Mute)
+   Feature: FF (Manufacturer specific feature)
+```
+
+We'll focus on the **Feature: 60 (Input Source)** ... I have good news and bad news:
+
+1. Good news: The display supports changing inputs with DDC!
+2. Bad news: **The inputs and the values are, for the most part, are bullsh\*t!!**
+
+Because of this, we will need to figure out the actual input values for each actual input of the monitor.
+
+You can use **ddcutil** again to figure them out like so:
+
+```
+# change the last number to figure the actual values that change the input. Have in mind these are hexadecimal values you'll need to convert to integers
+$ sudo ddcutil setvcp 0x60 0x01 
+```
+
+## Configuration
+
+Once you have the values for the inputs you want to control, you can fill out the config.yml inside the folder ddc-mqtt that you'd need for the software to run. For my display this would be:
+
+```
+mqtt:
+  username: #your mqtt server's username
+  password: #your mqtt server's password
+  host: 1.2.3.4 #your mqtt server's host
+  port: 1883
+display:
+  - id: 1 #display to control. if only a single monitor, this must be 1
+    inputs:
+      HDMI1: 5 # key: value — you can change the name of the input. The codes here are as integers, not hexadecimal
+      HDMI2: 6
+      HDMI3: 7
+      DP: 15
+interval: 20
+```
+
+## Setup
+
+You might want to use the docker container that comes with the code. If you use a Raspberry Pi you just do:
+
+```
+$ docker-compose up -d
+```
+
+And if your config is well formed, that should be it! 
+
+If you don't use a Raspberry Pi, you might need to pay attention to the *docker-compose.yml* in the root folder as we are 
+forwarding the i2c devices for the ddcutil library to access. 
+
+```
+    devices:
+      - "/dev/i2c-20:/dev/i2c-20"
+      - "/dev/i2c-21:/dev/i2c-21" #these might be different in your machine
+```
+
+## Usage
+
+If your MQTT server is shared or is part of a *Home Assistant* setup, the usage is simple. You'll get a device with switches to change inputs and that's all!
+
+![Display KVM](https://raw.githubusercontent.com/moimart/ddc-mqtt/main/hass_display_kvm.jpg)'
+
+If you want to use it MQTT RAW!!! you'd have access to the entities in the following paths:
+
+```
+Subscribe to kikkei/display-kvm/{number_of_display}/{input_name_in_the_config}/state -> with values 'true' or 'false' to check the state
+Publish 'ON' to kikkei/display-kvm/{number_of_display}/{input_name_in_the_config}/command for activation -> no need to send 'OFF'; switching is taken care of
+
+Example: kikkei/display-kvm/1/HDMI1/state
+```
+
+## Observations
+
+This software is polling at an interval to re-check of the state of the active input— just in case you switch it manually...
+
+This interval can be configured in the config.yml with the key interval. It is optional and by default is 20 seconds...
+
+I coded this to support multiple monitors but I have not tested it at all... contributions are very welcome! :)
+
+**Hope it works for you as well as it works for me!**

ddc-mqtt/devices.py

@@ -1,6 +1,6 @@
 device = {
     "identifiers": ["Kikkei Labs Display KVM"],
-    "name": "Display KVM",
+    "name": "Display KVM #?",
     "model": "Kikkei-display-kvm-0",
     "manufacturer": "Kikkei Labs",
 }
@@ -8,7 +8,7 @@ device = {
 
 display_device = {
     "identifiers": ["Input"],
-    "name": "Display Input KVM",
+    "name": "Display Input KVM #?",
     "model": "Kikkei-display-kvm",
     "manufacturer": "Kikkei Labs",
 }

ddc-mqtt/rename_to_config.yml

@@ -4,10 +4,10 @@ mqtt:
   host: 
   port: 1883
 display:
-  id: 1
+  - id: 1
     inputs:
-    hdmi1: 5
+      HDMI1: 5
-    hdmi2: 6
+      HDMI2: 6
-    hdmi3: 7
+      HDMI3: 7
-    dp: 15
+      DP: 15
-  
+interval: 20

ddc-mqtt/start.py

@@ -23,6 +23,8 @@ class Service:
                                 config["mqtt"]["host"],
                                 config["mqtt"]["port"])
         
+        poll_interval = 20 if "interval" not in config else config["interval"]
+        
         self.mqtt.delegate = self
         
         self.inputs = {}
@@ -30,27 +32,24 @@ class Service:
         
         print(display_data)
 
-        self.inputs = {
+        self.inputs = {}
-            display_data['id']: {
-                "switches": []
-            }
-        }
         
-        for input_name, input_code in display_data['inputs'].items():
+        for display in display_data:
-            self.create_display_switch(display_data['id'],input_name,input_code)
+            self.inputs[display['id']] = { "switches": [] }
+            for input_name, input_code in display['inputs'].items():
+                self.create_display_switch(display['id'],input_name,input_code)
             
-        self.timer = Timer(30, self)
+        self.timer = Timer(poll_interval, self)
         self.update_inputs_states()
         
     def update_inputs_states(self):
-        input_code = simpleddc.show_input()
+        for display_id in self.inputs.keys():
+            input_code = simpleddc.show_input(int(display_id))
         
             print(f"Input code is {input_code}")
             
-        for display_id in self.inputs.keys():
             for entry in self.inputs[display_id]["switches"]:
                 if entry["code"] == input_code:
-                    print("Found {}".format(entry["topic"]))
                     self.mqtt.client.publish(entry["topic"], "true")
                     entry["state"] = True
                 else:
@@ -101,7 +100,7 @@ class Service:
         config["state_topic"] = config["state_topic"].replace("?", input_name)
 
         device = display_device.copy()
-        device["name"] = device["name"].replace("#", input_name)
+        device["name"] = device["name"].replace("?", input_name)
         device["model"] = "{}-{}".format(device["model"],display_id)
         config["device"] = device
 

simpleddc-extension/simple-ddc.h

@@ -7,6 +7,7 @@
 #include <ddcutil_status_codes.h>
 
 DDCA_Display_Handle * open_first_display_by_dlist();
+DDCA_Display_Handle * open_display_by_dlist(unsigned int display);
 DDCA_Status switch_input(DDCA_Display_Handle* handle, uint8_t input);
 uint8_t show_any_value(
         DDCA_Display_Handle     dh,

simpleddc-extension/simpleddc-python.c

@@ -19,9 +19,16 @@ static PyObject* switch_to_input(PyObject* self, PyObject* args) {
 }
 
 static PyObject* show_input(PyObject* self, PyObject* args) {
-    DDCA_Display_Handle* handle = open_first_display_by_dlist();
+    uint8_t* display = malloc(sizeof(uint8_t));
+
+    if (!PyArg_ParseTuple(args, "i", display))
+        *display = 0;
+
+    DDCA_Display_Handle* handle = open_display_by_dlist(*display);
     int result = show_any_value(handle,DDCA_NON_TABLE_VCP_VALUE, 0x60);
     ddca_close_display(handle);
+
+    free(display);
     return PyLong_FromLong(result);
 }
 

simpleddc-extension/simpleddc.c

@@ -8,7 +8,8 @@
              ddca_rc_desc(status_code));              \
    } while(0)
 
-DDCA_Display_Handle * open_first_display_by_dlist() {
+DDCA_Display_Handle * open_first_display_by_dlist() 
+{
    printf("Check for monitors using ddca_get_displays()...\n");
    DDCA_Display_Handle dh = NULL;
 
@@ -20,13 +21,39 @@ DDCA_Display_Handle * open_first_display_by_dlist() {
 
    if (dlist->ct == 0) {
       printf("   No DDC capable displays found\n");
-   }
+   } else {
-   else {
       DDCA_Display_Info * dinf = &dlist->info[0];
       DDCA_Display_Ref * dref = dinf->dref;
       printf("Opening display %s\n", dinf->model_name);
       printf("Model: %s\n", dinf->model_name);
-      //printf("Model: %s\n", dinf->mmid.model_name);
+
+      DDCA_Status rc = ddca_open_display2(dref, false, &dh);
+      if (rc != 0) {
+          DDC_ERRMSG("ddca_open_display2", rc);
+      }
+   }
+   ddca_free_display_info_list(dlist);
+   return dh;
+}
+
+DDCA_Display_Handle * open_display_by_dlist(unsigned int display)
+{
+   DDCA_Display_Handle dh = NULL;
+
+   // Inquire about detected monitors.
+   DDCA_Display_Info_List* dlist = NULL;
+   ddca_get_display_info_list2(
+         false,    // don't include invalid displays
+         &dlist);
+
+   if (dlist->ct == 0 || dlist->ct < display) {
+      printf("   No DDC capable displays found\n");
+   } else {
+      DDCA_Display_Info * dinf = &dlist->info[display - 1];
+      DDCA_Display_Ref * dref = dinf->dref;
+      printf("Opening display %s\n", dinf->model_name);
+      printf("Model: %s\n", dinf->model_name);
+
       DDCA_Status rc = ddca_open_display2(dref, false, &dh);
       if (rc != 0) {
           DDC_ERRMSG("ddca_open_display2", rc);