Add subghz_demo application.

README.md

@@ -15,6 +15,9 @@ Feel free to reach out to me at CodeAllNight@outlook.com with any questions or l
 
 
 ## Subghz
+### subghz-plugins-subghz_demo
+[tutorial](./subghz/plugins/subghz_demo/README.md) - This is a demonstration of sending & receiving radio signals using the subghz_tx_rx worker library.
+
 ### subghz-protocol-x10-decoder
 [project](./subghz/protocols/x10/README.md) - This is a protocol decoder for the Flipper Zero to decode the x10 series of devices when doing a read from the Sub-GHz menu.
 

subghz/plugins/subghz_demo/README.md

@@ -0,0 +1,201 @@
+# SUBGHZ DEMO
+## Introduction
+This is a demonstration of sending & receiving radio signals using the subghz_tx_rx worker library.  This demo requires that you have two Flipper Zero devices.  If you only have one device, you can use a HackRF One or similar to capture/replay the RF signals to simulate a second device.
+
+## Installation Directions
+This project is intended to be overlayed on top of an existing firmware repo.
+- Clone, Build & Deploy an existing flipper zero firmware repo.  See this [tutorial](/firmware/updating/README.md) for updating firmware.
+- Copy the "subghz_demo" [folder](..) to the \applications\plugins\subghz_demo folder in your firmware.
+- Build & deploy the firmware.  See this [tutorial](/firmware/updating/README.md) for updating firmware.
+- NOTE: You can also extract the subghz_demo.FAP from resources.tar file and use qFlipper to copy the file to the SD Card/apps/Misc folder.
+
+
+## Running the updated firmware
+These directions assume you are starting at the flipper desktop.  If not, please press the back button until you are at the desktop.
+
+- Press the OK button on the flipper to pull up the main menu.
+- Choose "Applications" from the menu.
+- Choose "Misc" from the sub-menu.
+- Choose "Subghz Demo"
+
+- Do the same steps on your second Flipper.
+
+- The flipper should show a 4 digit number that keeps incrementing.
+- One the first Flipper press the OK button to send a count message to the other Flipper.
+- The other Flipper should show "Received ####" with the number you sent.
+- One the first Flipper press the UP button to send a tone message to the other Flipper.
+- The other Flipper should play a 440Hz tone.
+- If long press the UP button, the other Flipper should play a 880Hz tone. 
+
+- Press the BACK button to exit.
+
+
+## HackRF One
+- If you do not have two Flipper Zero devices, you can use a HackRF One to record messages & broadcast those messages at a future date.  I made a [YouTube](https://www.youtube.com/watch?v=S0sgcDQrVOc) video demo of how to record and broadcast messages.
+
+- To record a message: (replace "flipper-chat.rf" with the file name you want to use, such as "select-middle-sqaure.rf".)
+```
+sudo hackrf_transfer -r flipper-chat.rf -f 433920000 -s 8000000
+```
+
+- To broadcast a message: (replace "flipper-chat.rf" with the saved file name.) 
+```
+sudo hackrf_transfer -r flipper-chat.rf -f 433920000 -s 8000000 -x 47
+```
+
+- What I typically do is:
+  - Use the Flipper Zero to send a messasge that I record, then I play back that message at a later time when I want to pretend the other Flipper Zero is sending a message.  You can use the chat app in https://lab.flipper.net/cli, like shown in the video to send a specific packet (or you can use your own code to create the packet.) 
+  - Use the HackRF One to record the message from my Fliiper Zero.  Then later I use the chat app in https://lab.flipper.net/cli, to see what the message was (or I replay the message to see how my application would respond.)
+
+## Key concepts for subghz RX/TX
+- RX = Receive on a subghz (less than 1GHz) frequency.
+- TX = Transmit on a subghz (less than 1 GHZ) frequency.
+- Different countries/regions have different laws about [allowed](https://docs.flipperzero.one/sub-ghz/frequencies) broadcast frequencies.  Typically a country allows for broadcasting at 433.92MHz and/or 315.0MHz.
+- When sending data, it's useful for the packet to start with something unique to your application (so you know if the message you receive is for your application or some other application.)  The format used by this demo is:
+  - First part of message is - SUBGHZ_GAME_NAME (like "SGDEMO:")  This ends with a ":" delimiter, so that "SGDEMO" won't match "SGDEMO2" (because "SGDEMO2:" does not start with "SGDEMO:").
+  - The next part is the purpose for the message (which is a single byte.)  (This can be anything your game requires; like a player move, tone to play, message to display, etc.)
+  - The next part is the major version of the application (which is a single byte.)
+  - Next is any game parameter data (this can be empty).  (Like the square that was selected, new board layout, etc.)
+  - Then is the ':' delimiter character.
+  - Finally is the name of the flipper (as returned from furi_hal_version_get_name_ptr().)
+- Broadcast packets should be truncated to MESSAGE_MAX_LEN (which is typically around 60 bytes.)
+- Data in sent packets should not be trusted, always expect to get some malformed input.
+
+## Adding subghz RX/TX to your project
+- NOTE: Feel free to copy any code from this tutorial, as long as your license does not add any additional requirements for this tutorial. 
+
+- Import the library:
+```
+    #include <lib/subghz/subghz_tx_rx_worker.h>
+```
+
+- Define MESSAGE_MAX_LEN with the maximum size (in bytes) of a message.  Messages are typically UTF-8 encoded, but it is up to the sending application to decide.  I beleive the maximum for the CC1101 chip is in the low-60 bytes.  
+```
+  #define MESSAGE_MAX_LEN 60
+```
+
+- Define SUBGHZ_GAME_NAME to be the data you will send at the beginning part of each message.  This is optional, but it will help make your application more robust in the case where other unrelated applications are running on similar frequencies.
+```
+// This is sent at the beginning of all RF messages. You should make the SUBGHZ_GAME_NAME short but unique.
+#define SUBGHZ_GAME_NAME "SGDEMO:"
+```
+
+- Create a callback method that will get invoked when data is available.  This callback method should just queue a message that data was detected.  Do not copy this code directly, but instead follow the pattern used in our application for queuing a mesage (and add a new "EventDataDetected" type.)
+```
+  static void rx_event_callback(void* ctx) { 
+    // Queue a message that data was detected.
+    AppContext* context = ctx;
+    Event event = {.type = EventDataDetected};
+    furi_message_queue_put(context->queue, &event, FuriWaitForever);
+  }
+```
+
+- In your application entrypoint method: 
+
+  - Decide on a frequency (if your application is global, you should provide a way to set it to a valid region):
+  ```
+      uint32_t frequency = 433920000;
+  ```
+
+  - Check to see if broadcasting is allowed on the frequency. 
+  ```
+      if (!furi_hal_subghz_is_tx_allowed(frequency)) { /* show error about TX not allowed! */ }
+  ```
+
+  - Allocate the subghz TX/RX worker.
+  ```
+      demo_context->subghz_txrx = subghz_tx_rx_worker_alloc();
+  ```
+
+  - Start the worker.
+  ```
+      bool worker_started = subghz_tx_rx_worker_start(demo_context->subghz_txrx, frequency);
+  ```
+
+  - If the worker failed (worker_started == false) then free resources and exit.
+
+  - Configure a callback method for when new data is received.
+    - Second parameter should match the name of your function.  For example if your callback function is "static void rx_event_callback(void* ctx) { /* queue got data message */ }" then you would use "rx_event_callback". 
+  ```
+      subghz_tx_rx_worker_set_callback_have_read(
+        demo_context->subghz_txrx,
+        rx_event_callback,
+        demo_context);
+  ```
+
+  -  All the subghz CLI apps disable charging; so our demo does it too.
+  ```
+      furi_hal_power_suppress_charge_enter();
+  ```
+
+  - At this point you are all configured for transmitting and receiving messages!
+
+  - When your application exits, you should free all of the resources &amp; reenable charging.
+  ```
+    if(subghz_tx_rx_worker_is_running(demo_context->subghz_txrx)) {
+        subghz_tx_rx_worker_stop(demo_context->subghz_txrx);
+    }
+    subghz_tx_rx_worker_free(demo_context->subghz_txrx);
+    furi_hal_power_suppress_charge_exit();
+  ```
+
+- Create a received_data method that will get invoked to read &amp; process new RX data.  
+```
+  static void receive_data(DemoContext* instance) {
+    uint8_t message[MESSAGE_MAX_LEN] = {0};
+    memset(message, 0x00, MESSAGE_MAX_LEN);
+    size_t len = subghz_tx_rx_worker_read(instance->subghz_txrx, message, MESSAGE_MAX_LEN);
+    
+    // The data is now in message buffer!  
+    
+    // Typically you want to parse and validate the data.  
+    // If the message needs further processing, then queue
+    // a message with the parsed data set in the event properties.
+    // (Important -- If you allocate any memory and assign pointers
+    // in your event data, make sure that the code that processes
+    // your event will free the memory!)
+  }
+```
+
+- In your furi_message_queue_get/switch(event.type) loop, add a case for EventDataDetected.  Call your receive_data method.
+```
+  case EventDataDetected:
+    // Another Flipper sent us data! Process it, potentially queuing an event.
+    receive_data(demo_context);
+  break;
+```
+
+- In your furi_message_queue_get/switch(event.type) loop, you will typically want to add processing for the other events that are queued in your receive_data method. For example EventRemotePlayerMoved.
+
+- If you want to send data, create a UTF8 buffer with the data to send, ensuring that the total buffer length is less than MESSAGE_MAX_LEN.  If your message is 7-bit ASCII (like A-Z a-z 0-9 symbols spaces) then you don't necessarily need to convert to UTF8 (since characters 0-127 are the same in both ASCII and UTF8.)  If you might have special characters (emojis, characters with accents, etc.) they you should convert to UTF8 first.
+```
+    uint8_t* message = (uint8_t*)furi_string_get_cstr(buffer);
+
+    // Make sure our message will fit into a packet; if not truncate it.
+    size_t length = strlen((char*)message);
+    if (length>MESSAGE_MAX_LEN) {
+        message[MESSAGE_MAX_LEN-1] = 0;
+        message[MESSAGE_MAX_LEN-2] = '\n';
+        message[MESSAGE_MAX_LEN-2] = '\r';
+        length = MESSAGE_MAX_LEN;
+    }
+
+    while(!subghz_tx_rx_worker_write(demo_context->subghz_txrx, message, length)) {
+        // Wait a few milliseconds on failure before trying to send again.
+        furi_delay_ms(20);
+    }
+```
+
+## Details about the project files
+- application.fam
+  - specifies the name of our application.
+  - specifies the entry point for our application.
+  - specifies we use the GUI.
+  - specifies our icon is the gpio_polling_demo.png file.
+  - specifies our application can be found in the "Misc" category.
+
+- subghz_demo.png
+  - The icon for our application that shows up in the "Misc" folder.
+
+- subghz_demo.c
+  - This is the demo applcation.

subghz/plugins/subghz_demo/application.fam

@@ -0,0 +1,10 @@
+App(
+    appid="Subghz_Demo",
+    name="Subghz Demo",
+    apptype=FlipperAppType.EXTERNAL,
+    entry_point="subghz_demo_app",
+    requires=["gui", "subghz"],
+    stack_size=2 * 1024,
+    fap_icon="subghz_demo.png",
+    fap_category="Misc",
+)

subghz/plugins/subghz_demo/subghz_demo_app.c

@@ -0,0 +1,489 @@
+/*
+@CodeAllNight
+https://github.com/jamisonderek/flipper-zero-tutorials
+
+This is a demonstration of sending radio signals using the subghz_tx_rx worker library.
+
+Features:
+Press OK on Flipper Zero to send the current count to another Flipper Zero.
+Short press UP button on Flipper Zero to send 440Hz tone to another Flipper Zero.
+Long press UP button on Flipper Zero to send 880Hz tone to another Flipper Zero. 
+
+*/
+
+#include <furi.h>
+#include <furi_hal.h>
+#include <furi_hal_resources.h>
+#include <gui/gui.h>
+#include <locale/locale.h>
+
+#include <lib/subghz/subghz_tx_rx_worker.h>
+
+// This is sent at the beginning of all RF messages.
+// You should make the SUBGHZ_GAME_NAME short but unique.
+// NOTE: It must end with the ':' character.
+#define SUBGHZ_GAME_NAME "SGDEMO:"
+
+// The message max length should be no larger than a value around 60 to 64.
+#define MESSAGE_MAX_LEN 60
+
+// The major version must be a single character (it can be anything - like '1' or 'A' or 'a').
+#define MAJOR_VERSION 'A'
+
+// When an RF message is sent, it includes a purpose so the receiving application
+// can decide if it should process the message.
+typedef enum {
+    DemoRfPurposeCounter = 'C', // The message is about the counter.
+    DemoRfPurposeTone = 'T', // The message is about a note to play.
+} DemoRfPurpose;
+
+// Messages in our event queue are one of the following types.
+typedef enum {
+    DemoEventTypeTick,
+    DemoEventTypeKey,
+    DemoEventDataDetected,
+
+    // You can add additional events here.
+    DemoEventSendCounter,
+    DemoEventReceivedCounter,
+    DemoEventSendTone,
+    DemoEventReceivedTone,
+} DemoEventType;
+
+// An item in the event queue has both the type and its associated data.
+// Some data fields are only set for particular types.
+typedef struct {
+    DemoEventType type; // The reason for this event.
+    
+    // You can add additional data that is helpful for your events.
+    InputEvent input;   // This data is specific to DemoEventTypeKey.
+    unsigned int number; // This data is specific to DemoEventSendCounter/DemoEventReceivedCounter/DemoEventSendTone/DemoEventReceivedTone.
+    FuriString* senderName; // This data is specific to DemoEventReceivedCounter.
+} DemoEvent;
+
+// This is the data for our application.  You might have a game board, 
+// current player, etc.  For this demo we have two counters & a general purpose buffer.
+typedef struct {
+    FuriString* buffer;
+
+    // You can add additional application state here.
+    unsigned int localCounter;
+    unsigned int remoteCounter;
+} DemoData;
+
+// This is our application context.
+typedef struct {
+    FuriMessageQueue* queue; // Message queue (DemoEvent items to process).
+    FuriMutex* mutex; // Used to provide thread safe access to data.
+    DemoData* data; // Data accessed by multiple threads (acquire the mutex before accessing!)
+    
+    // Used for subghz communication
+    SubGhzTxRxWorker* subghz_txrx;
+} DemoContext;
+
+// We register this callback to get invoked whenever new subghz data is received.
+// We queue a DemoEventDataDetected message and then return to the caller.
+static void subghz_demo_worker_update_rx_event_callback(void* ctx) {
+    furi_assert(ctx);
+    DemoContext* demo_context = ctx;
+    DemoEvent event = {.type = DemoEventDataDetected};
+    furi_message_queue_put(demo_context->queue, &event, FuriWaitForever);
+}
+
+// This gets invoked when we process a DemoEventDataDetected event.
+// We read the message using subghz_tx_rx_worker_read.
+// We determine if the message is in the valid format.
+// If valid, we queue a DemoEventReceivedCounter/Tone message with the counter/frequency.
+// IMPORTANT: The code processing our event needs to furi_string_free the senderName!
+static void subghz_demo_receive_data(DemoContext* instance) {
+    uint8_t message[MESSAGE_MAX_LEN] = {0};
+    memset(message, 0x00, MESSAGE_MAX_LEN);
+    size_t len = subghz_tx_rx_worker_read(instance->subghz_txrx, message, MESSAGE_MAX_LEN);
+    size_t game_name_len = strlen(SUBGHZ_GAME_NAME);
+    if (len < (game_name_len + 2)) {
+        // Message wasn't big enough to have our game name + the reason code + version; so it must not be for us. 
+        return;
+    }
+
+    // The message for a counter (like 42) should be "SGDEMO:" + "C" + "0042" + ":" + "YourFlip" + "\r\n"
+    if (strcmp(SUBGHZ_GAME_NAME, (const char*)message)) {
+        // The purpose immediately follows the game name.
+        DemoRfPurpose purpose = message[game_name_len];
+        uint8_t version = message[game_name_len+1];
+
+        UNUSED(version);
+        // Right now we don't care about the veresion of the application, but in the future we might need to
+        // respond differently based on the version of the application running on the other Flipper Zero.
+        // Important: Don't always trust what is sent, some people with Flipper Zero might send an 
+        // invalid version to trick your code into interpreting the payload in a special way.
+        
+        unsigned int number;
+        char senderName[9];
+        switch (purpose) {
+            case DemoRfPurposeCounter:
+                // We expect this mesage to contain both the count and the sender name.
+                if (sscanf((const char*)message+game_name_len+2, "%04u:%8s", &number, senderName) == 2) {
+                    // IMPORTANT: The code processing the event needs to furi_string_free the senderName!
+                    FuriString* name = furi_string_alloc();
+                    furi_string_set(name, senderName);
+                    // The counter is supposed to be a 4 digit number.
+                    if (number > 10000U) {
+                        number %= 10000;
+                    }
+                    DemoEvent event = {.type = DemoEventReceivedCounter, .number = number, .senderName = name};
+                    furi_message_queue_put(instance->queue, &event, FuriWaitForever);
+                }
+            break;
+
+            case DemoRfPurposeTone:
+                // We expect this message to contain both the frequency and the sender name.
+                if (sscanf((const char*)message+game_name_len+2, "%u:%8s", &number, senderName) == 2) {
+                    // IMPORTANT: The code processing the event needs to furi_string_free the senderName!
+                    FuriString* name = furi_string_alloc();
+                    furi_string_set(name, senderName);
+                    DemoEvent event = {.type = DemoEventReceivedTone, .number = number, .senderName = name};
+                    furi_message_queue_put(instance->queue, &event, FuriWaitForever);
+                }
+            break;
+
+            // Add parsing for other messages here.
+
+            default:
+            break;
+        }
+    }
+}
+
+// This gets invoked when input (button press) is detected.  
+// We queue a DemoEventTypeKey message with the input event data.
+static void subghz_demo_input_callback(InputEvent* input_event, void* ctx_q) {
+    furi_assert(ctx_q);
+    FuriMessageQueue* queue = ctx_q;
+    DemoEvent event = {.type = DemoEventTypeKey, .input = *input_event};
+    furi_message_queue_put(queue, &event, FuriWaitForever);
+}
+
+// We register this callback to get invoked by the timer on every tick.  
+// We queue a DemoEventTypeTick message and then return to the caller.
+static void subghz_demo_tick_callback(void* ctx_q) {
+    furi_assert(ctx_q);
+    FuriMessageQueue* queue = ctx_q;
+    DemoEvent event = {.type = DemoEventTypeTick};
+    // We don't pass a wait value for 3rd parameter -- this event is not critical (and will happen again soon).
+    furi_message_queue_put(queue, &event, 0);
+}
+
+// Our DemoEventTypeKey handler invokes this method when user clicks OK button.
+// We queue a DemoEventSendCounter message with the counter data.
+static void subghz_demo_send_count(void* ctx) {
+    furi_assert(ctx);
+    DemoContext* demo_context = ctx;
+    FuriMessageQueue* queue = demo_context->queue;
+    DemoData* data = demo_context->data;
+    unsigned int counter = data->localCounter;
+    DemoEvent event = {.type = DemoEventSendCounter, .number = counter};
+    furi_message_queue_put(queue, &event, FuriWaitForever);
+}
+
+// Our DemoEventTypeKey handler invokes this method when user clicks UP button.
+// We queue a DemoEventSendTone message with the frequency data.
+static void subghz_demo_send_tone(void* ctx, unsigned int frequency) {
+    furi_assert(ctx);
+    DemoContext* demo_context = ctx;
+    DemoData* data = demo_context->data;
+    FuriMessageQueue* queue = demo_context->queue;
+    DemoEvent event = {.type = DemoEventSendTone, .number = frequency};
+    furi_message_queue_put(queue, &event, FuriWaitForever);
+}
+
+// We register this callback to get invoked whenever we need to render the screen. 
+// We render the UI on this callback thread.
+static void subghz_demo_render_callback(Canvas* canvas, void* ctx) {
+    furi_assert(ctx);
+    DemoContext* demo_context = ctx;
+
+    // Attempt to aquire context, so we can read the data.
+    if(furi_mutex_acquire(demo_context->mutex, 200) != FuriStatusOk) {
+        return;
+    }
+
+    DemoData* data = demo_context->data;
+    unsigned int localCounter = data->localCounter;
+    unsigned int remoteCounter = data->remoteCounter;
+    // The counter is supposed to be a 4 digit number.
+    furi_assert(localCounter < 10000U);
+    furi_assert(remoteCounter < 10000U);
+
+    // Other fonts are FontPrimary, FontSecondary, FontKeyboard, FontBigNumbers,
+    canvas_set_font(canvas, FontPrimary);
+    canvas_draw_str_aligned(canvas, 5, 8, AlignLeft, AlignCenter, "Press OK to send count.");
+    canvas_draw_str_aligned(canvas, 5, 20, AlignLeft, AlignCenter, "Press UP to send tone.");
+
+    furi_string_printf(data->buffer, "%04u", localCounter);
+    canvas_set_font(canvas, FontSecondary);
+    canvas_draw_str_aligned(canvas, 64, 42, AlignCenter, AlignTop, furi_string_get_cstr(data->buffer));
+
+    if (remoteCounter > 0) {
+        furi_string_printf(data->buffer, "Received %04u", remoteCounter);
+        canvas_draw_str_aligned(canvas, 64, 52, AlignCenter, AlignTop, furi_string_get_cstr(data->buffer));
+    }
+
+    furi_mutex_release(demo_context->mutex);
+}
+
+// Our DemoEventTypeTick handler invokes this method.
+// We increment our counter (wrapping back to 0 if it exceeds a 4 digit number.)
+static void subghz_demo_update_local_counter(DemoContext* demo_context) {
+    DemoData* data = demo_context->data;
+    
+    // Increment the counter (which is supposed to be a 4 digit number for this app.)
+    data->localCounter++;
+    if (data->localCounter > 10000U) {
+        data->localCounter = 0;
+    }
+}
+
+// Our DemoEventReceivedCounter handler invokes this method.
+// We update our remote counter.
+static void subghz_demo_update_remote_counter(DemoContext* demo_context, DemoEvent* event) {
+    // The queueing code should have made sure the value was valid.
+    furi_assert(event->number < 10000);
+    DemoData* data = demo_context->data;
+
+    data->remoteCounter = event->number;
+
+    // The message contains a sender name furi_string that we need to free, even if we didn't use it.
+    if (event->senderName) {
+        furi_string_free(event->senderName);
+    }
+}
+
+// Our DemoEventReceivedTone handler invokes this method.
+// We play a quick (100ms) tone of the desired frequency.
+static void subghz_demo_play_tone(DemoContext* demo_context, DemoEvent* event) {
+    DemoData* data = demo_context->data;
+
+    unsigned int frequency = event->number;
+
+    // Make tones if the speaker is available.
+	if (furi_hal_speaker_acquire(1000)) { 
+        float freq = (float)frequency;
+        float volume = 1.0f;
+        furi_hal_speaker_start(freq, volume);
+        furi_delay_ms(100);
+        furi_hal_speaker_stop();
+        furi_hal_speaker_release();
+    }
+
+    // The message contains a sender name furi_string that we need to free, even if we didn't use it.
+    if (event->senderName) {
+        furi_string_free(event->senderName);
+    }
+}
+
+// This is a helper method that broadcasts a buffer.
+// If the message is too large, the message will get truncated.
+static void subghz_demo_broadcast(DemoContext* demo_context, FuriString* buffer) {
+    uint8_t* message = (uint8_t*)furi_string_get_cstr(buffer);
+
+    // Make sure our message will fit into a packet; if not truncate it.
+    size_t length = strlen((char*)message);
+    if (length>MESSAGE_MAX_LEN) {
+        message[MESSAGE_MAX_LEN-1] = 0;
+        message[MESSAGE_MAX_LEN-2] = '\n';
+        message[MESSAGE_MAX_LEN-2] = '\r';
+        length = MESSAGE_MAX_LEN;
+    }
+
+    while(!subghz_tx_rx_worker_write(demo_context->subghz_txrx, message, length)) {
+        // Wait a few milliseconds on failure before trying to send again.
+        furi_delay_ms(20);
+    }
+}
+
+// Our DemoEventSendCounter handler invokes this method.
+// We broadcast - "game name + purpose (Counter) + 4 digit counter value + : + Flipper name + \r\n"
+static void subghz_demo_broadcast_counter(DemoContext* demo_context, unsigned int counterToSend) {
+    // The counter is supposed to be a 4 digit number.
+    furi_assert(counterToSend < 10000);
+    DemoData* data = demo_context->data;
+
+    // The message for a counter with value 42 should look like...  "SGDEMO:CA0042:YourFlip\r\n"
+    furi_string_printf(data->buffer, "%s%c%c%04u:%s\r\n", SUBGHZ_GAME_NAME, DemoRfPurposeCounter, MAJOR_VERSION, counterToSend, furi_hal_version_get_name_ptr());
+
+    subghz_demo_broadcast(demo_context, data->buffer);
+}
+
+// Our DemoEventSendTone handler invokes this method.
+// We broadcast - "game name + purpose (Tone) + frequency + : + Flipper name + \r\n"
+static void subghz_demo_broadcast_tone(DemoContext* demo_context, unsigned int frequency) {
+    DemoData* data = demo_context->data;
+
+    // The message for a frequency of 440 should look like...  "SGDEMO:TA440:YourFlip\r\n"
+    furi_string_printf(data->buffer, "%s%c%c%u:%s\r\n", SUBGHZ_GAME_NAME, DemoRfPurposeTone, MAJOR_VERSION, frequency, furi_hal_version_get_name_ptr());
+
+    subghz_demo_broadcast(demo_context, data->buffer);
+}
+
+// This is the entry point for our application, which should match the application.fam file.
+int32_t subghz_demo_app(void* p) {
+    UNUSED(p);
+
+    // For this demo we hardcode to 433.92MHz.
+    uint32_t frequency = 433920000;
+
+    // TODO: Have an ordered list of frequencies we try, instead of just 1 frequency.
+
+    // Since this demo transmits RF, we see if it is allowed.
+    if(!furi_hal_subghz_is_tx_allowed(frequency)) {
+        // For this demo we don't show a friendly error about not being
+        // allowed to broadcast on this frequency.  Instead the application
+        // just exits.
+        return 1;
+    }
+
+    // Configure our initial data.
+    DemoContext* demo_context = malloc(sizeof(DemoContext));
+    demo_context->mutex = furi_mutex_alloc(FuriMutexTypeNormal);
+    demo_context->data = malloc(sizeof(DemoData));
+    demo_context->data->buffer = furi_string_alloc();
+    demo_context->data->localCounter = 0;
+    demo_context->data->remoteCounter = 0;
+
+    // Queue for events (tick or input)
+    demo_context->queue = furi_message_queue_alloc(8, sizeof(DemoEvent));
+
+    // Subghz worker.
+    demo_context->subghz_txrx = subghz_tx_rx_worker_alloc();
+
+    // Try to start the TX/RX on the frequency and configure our callback
+    // whenever new data is received.
+    if(subghz_tx_rx_worker_start(demo_context->subghz_txrx, frequency)) {
+        subghz_tx_rx_worker_set_callback_have_read(
+            demo_context->subghz_txrx, subghz_demo_worker_update_rx_event_callback, demo_context);
+    } else {
+        // For this demo we don't show a friendly error about not being
+        // allowed to broadcast on this frequency.  Instead the application
+        // just exits.
+        if(subghz_tx_rx_worker_is_running(demo_context->subghz_txrx)) {
+            subghz_tx_rx_worker_stop(demo_context->subghz_txrx);
+        }
+        subghz_tx_rx_worker_free(demo_context->subghz_txrx);
+        furi_message_queue_free(demo_context->queue);
+        furi_mutex_free(demo_context->mutex);
+        furi_string_free(demo_context->data->buffer);
+        free(demo_context->data);
+        free(demo_context);
+        return 2;
+    }
+
+    // All the subghz CLI apps disable charging; so our demo does it too.
+    furi_hal_power_suppress_charge_enter();
+
+    // Set ViewPort callbacks
+    ViewPort* view_port = view_port_alloc();
+    view_port_draw_callback_set(view_port, subghz_demo_render_callback, demo_context);
+    view_port_input_callback_set(view_port, subghz_demo_input_callback, demo_context->queue);
+
+    // Open GUI and register view_port
+    Gui* gui = furi_record_open(RECORD_GUI);
+    gui_add_view_port(gui, view_port, GuiLayerFullscreen);
+
+    // Update the screen fairly frequently (every 250 milliseconds.)
+    FuriTimer* timer = furi_timer_alloc(subghz_demo_tick_callback, FuriTimerTypePeriodic, demo_context->queue);
+    furi_timer_start(timer, 250);
+
+    // Main loop
+    DemoEvent event;
+    bool processing = true;
+    do {
+        if (furi_message_queue_get(demo_context->queue, &event, FuriWaitForever) == FuriStatusOk) {
+            switch (event.type) {
+                case DemoEventTypeKey:
+                    // Short press of OK button, queue DemoEventSendCounter event with the current count.
+                    if(event.input.type == InputTypeShort && event.input.key == InputKeyOk) {
+                        furi_mutex_acquire(demo_context->mutex, FuriWaitForever);
+                        subghz_demo_send_count(demo_context);
+                        furi_mutex_release(demo_context->mutex);
+                    }
+                    // Short press of UP button, queue DemoEventSendTone event.
+                    else if(event.input.type == InputTypeShort && event.input.key == InputKeyUp) {
+                        furi_mutex_acquire(demo_context->mutex, FuriWaitForever);
+                        subghz_demo_send_tone(demo_context, 440U);
+                        furi_mutex_release(demo_context->mutex);
+                    } 
+                    // Long press of UP button, queue DemoEventSendTone event.
+                    else if (event.input.type == InputTypeLong && event.input.key == InputKeyUp) {
+                        furi_mutex_acquire(demo_context->mutex, FuriWaitForever);
+                        subghz_demo_send_tone(demo_context, 880U);
+                        furi_mutex_release(demo_context->mutex);
+                    }
+                    // Short press of back button exits the program.
+                    else if(event.input.type == InputTypeShort && event.input.key == InputKeyBack) {
+                        processing = false;
+                    }
+                    break;
+                case DemoEventTypeTick:
+                    // Every timer tick we update the counter. 
+                    furi_mutex_acquire(demo_context->mutex, FuriWaitForever);
+                    subghz_demo_update_local_counter(demo_context);
+                    furi_mutex_release(demo_context->mutex);
+                    break;
+                case DemoEventSendCounter:
+                    // Actually send the counter value to the other Flipper Zero.
+                    furi_mutex_acquire(demo_context->mutex, FuriWaitForever);   
+                    subghz_demo_broadcast_counter(demo_context, event.number);
+                    furi_mutex_release(demo_context->mutex);
+                    break;
+                case DemoEventSendTone:
+                    // Actually send the frequency value to the other Flipper Zero.
+                    furi_mutex_acquire(demo_context->mutex, FuriWaitForever);   
+                    subghz_demo_broadcast_tone(demo_context, event.number);
+                    furi_mutex_release(demo_context->mutex);
+                case DemoEventDataDetected:
+                    // Another Flipper sent us data!  Process it, potentially queuing an event.
+                    subghz_demo_receive_data(demo_context);
+                    break;
+                case DemoEventReceivedCounter:
+                    // Process the counter sent by the other Flipper Zero.
+                    furi_mutex_acquire(demo_context->mutex, FuriWaitForever);   
+                    subghz_demo_update_remote_counter(demo_context, &event);
+                    furi_mutex_release(demo_context->mutex);
+                case DemoEventReceivedTone:
+                    // Process the tone sent by the other Flipper Zero.
+                    furi_mutex_acquire(demo_context->mutex, FuriWaitForever);   
+                    subghz_demo_play_tone(demo_context, &event);
+                    furi_mutex_release(demo_context->mutex);
+                default:
+                    break;
+            }
+
+            // Send signal to update the screen (callback will get invoked at some point later.)
+            view_port_update(view_port);
+        } else {
+            // We had an issue getting message from the queue, so exit application.
+            processing = false;
+        }
+    } while (processing);
+
+    // Free resources
+    furi_timer_free(timer);
+    if(subghz_tx_rx_worker_is_running(demo_context->subghz_txrx)) {
+        subghz_tx_rx_worker_stop(demo_context->subghz_txrx);
+    }
+    subghz_tx_rx_worker_free(demo_context->subghz_txrx);
+    view_port_enabled_set(view_port, false);
+    gui_remove_view_port(gui, view_port);
+    view_port_free(view_port);
+    furi_record_close(RECORD_GUI);
+    furi_message_queue_free(demo_context->queue);
+    furi_mutex_free(demo_context->mutex);
+    furi_string_free(demo_context->data->buffer);
+    free(demo_context->data);
+    free(demo_context);
+   
+    // Reenable charging.
+    furi_hal_power_suppress_charge_exit();
+    
+    return 0;
+}