diff --git a/POCSAG-Receiver.md b/POCSAG-Receiver.md index 27592c3..902af7f 100644 --- a/POCSAG-Receiver.md +++ b/POCSAG-Receiver.md @@ -1,43 +1,50 @@ -With this app you can receive pager messages using the POCSAG protocol. +Receives pager messages using the POCSAG protocol. -This protocol operates in the VHF/UHF bands using FSK modulation. More technical details can be found by following the links in the References section. +This protocol operates in the VHF/UHF bands using FSK modulation. +More technical details can be found by following the links in the References section. -# Display summary +# UI Overview -[[img/screenshots/Receive_POCSAG.png]] +![POCSAG_UI](https://github.com/eried/portapack-mayhem/assets/3761006/bb4795e7-1b1f-4b31-8663-ddc71d1535d4) -Description of displayed information, starting from top-left: - -- Receiver frequency, RF amplifier, LNA, VGA, RSSI and Channel indicators -- Phase, Bit/baud rate, Log checkbox -- Ignore address checkbox and address -- The lower area of the display will show the latest received messages. - -## Settings +![POCSAG_UI_Detail](https://github.com/eried/portapack-mayhem/assets/3761006/1c0faccf-aec3-4a44-b183-8731d24642f1) +### Settings - **Frequency**: Sets the frequency to receive pager messages on. Can be adjusted with the [encoder thumb wheel](Hardware-overview), on-screen numpad, or loaded from frequencies saved on an SD card. 439.9875 MHz is the most popular worldwide frequency used by Amateur radio for POCSAG. Amateur radio POCSAG uses 1200bps. -- **RF amplifier**: (0 or 1): Enables/disables the internal RF amplifier. +- **RF amplifier** (0 or 1): Enables/disables the internal RF amplifier. - **LNA gain** (0, 8, 16, 24, 32, 40): Sets the LNA gain. Further information: [Description of the gain settings](Help!-Im-not-receiving-anything!---Receive-Quality-Issues#description-of-the-gain-settings) - **VGA gain** (0 to 62): Sets the VGA gain. Further information: [Description of the gain settings](Help!-Im-not-receiving-anything!---Receive-Quality-Issues#description-of-the-gain-settings) -- **Phase** (Positive or Negative): Usually set to positive. Typically the FSK lower frequency designates a high bit. Setting the phase polarity to negative will invert this, so the FSK lower frequency now designates a low bit. -- **Data rate** (512pbs, 1200bps, 2400bps): Sets the baud rate (bits per second) of the received data. Typically older paging systems use 512bps, while newer systems use 1200bps or 2400bps. -- **Log checkbox**: Enable/disable logging of received messages to an SD card. This log can be found on the SD card root directory, filename: `pocsag.txt`. -- **Ignore address checkbox**: Used to ignore messages sent to the address set. +- **Squelch** (0-99): Sets the signal to noise threshold. 0 disables squelch. Higher values allow more noise. Should be set so that strong signals are clearly received without any dropped audio. +- **Volume**: Output volume for the received audio. Can be used to monitor received signal quality. -## Message display +### Infomation +- **Decoder Status**: Indicates the status of the decoder state machine. White: Idle, Cyan: Clear, Yellow: Waiting for message start, Green: Waiting for rest of message. +- **Batch Count**: Number of message batches that have been received. A batch has 16 codewords. +- **Bits**: Displays the bits that are being decoded into codewords. +- **Sync**: Green when the frame decoder has received a "sync" frame. Messages are not decoded unless a sync frame is found. +- **Codewords**: Shows the number of codewords in the current batch. When the bar fills, the batch is complete and is processed. +- **Baud Rate**: The detected rate of the current message. 05: 512bps, 12: 1200bps, 24: 2400bps. -Typical received message: +### Buttons +- **Ignore Last**: Enables "Ignore" mode for the last received address. +- **Config**: Enters the settings page to configure options. +## Config +*TODO* + +## Message Display + +Typical message: ```plaintext -12:34 1200bps ADDR:432123 F2 +12:34 1200 #432123 F2 This is a test message ``` Description (from top-left): - `12:34` - **Time**: The time that the message was received (time from PortaPack). -- `1200bps` - **Data rate**: The data rate used to receive the message. -- `ADDR:432123` - **Address**: The address of the intended pager recipient. +- `1200` - **Data rate**: The data rate used to receive the message. +- `#432123` - **Address**: The address of the intended pager recipient. - `F2` - **Function**: (0 to 3) Indicates the type or source of message sent (can be used to provide a category of sorts). - `This is a test message` - **Message**: The message data displayed as ASCII.