TASK_ID = RF001A_OTA_TX_001
TASK_TITLE = Transmit first RF-001A QPSK packet burst
SOURCE_BRANCH = video-development
EXPECTED_HEAD = 1e3aa25d7007c7c8e84608cddb02f06f77e63396
REQUIRES_APPROVAL = YES
HARDWARE_ACCESS = YES
RF_RX = NO
RF_TX = YES
ALLOW_COMMIT = NO
ALLOW_PUSH = NO
RISK_LEVEL = RED

This file is the authoritative current task for the MAIN PC TX node.
Read TX_NODE_STATE.md first. If chat history, this file, the shared RF-001A spec and current Git HEAD conflict, stop and report the conflict.

# Current TX task

TASK =
TRANSMIT FIRST RF-001A QPSK PACKET BURST

This is a new RED task. It does not inherit the RX task approval. Publication of this file is not permission to transmit.

Before any RF TX, the user must:

1. separately provide the exact authorization `AUTHORIZE RF TX`;
2. confirm the live RX status `RX READY FOR TX = YES` for task `RF001A_OTA_CAPTURE_001`.

A normal approval, an earlier RF authorization, or an RX approval is insufficient.

## 1. Fixed RF-001A parameters

```text
center frequency = 1400000000 Hz
sample rate = 8000000 samples/s
modulation = QPSK
symbol rate = 500000 symbols/s
inner FEC = 2/3
payload = 256 bytes
packet count = 100
inter-packet gap = 5 ms
digital carrier offset = +125000 Hz
TX VGA = 20 dB
RF amp = OFF
antenna bias = OFF
common 10 MHz reference = VERIFIED
distance = approximately 2 m
LOS = YES
video = OFF
```

The waveform is one finite burst. Never add `-R`.

## 2. Preconditions

Before asking for RED authorization, prepare all read-only evidence:

1. Run `git pull --ff-only origin video-development`.
2. Require branch `video-development`.
3. Require `git status --short --untracked-files=no` to produce no output.
4. Require local HEAD to equal `origin/video-development` and `EXPECTED_HEAD` to be its ancestor.
5. Run `hackrf_info` and preserve complete stdout.
6. Require TX serial `000000000000000097c063dc323b97d3`.
7. Require the recorded MASTER CLKOUT command result = `PASS`.
8. Require the user to confirm both TX and RX antennas connected, approximately 2 m LOS and the intended antenna geometry.
9. Require the current RX report to show `RX READY FOR TX = YES`, task ID `RF001A_OTA_CAPTURE_001`, a live capture PID, capture path, start time and expected end time.
10. Require current time to be before the RX expected end time.

Verify the prepared waveform without accessing radio hardware:

```powershell
python -B -X utf8 tools/rf001a_prepare.py --verify-dir data/raw/rf001/rf001a_common_clock_001
```

Then verify the actual hardware-format bytes through the existing receiver. The report path must be new and outside Git:

```powershell
python -B -X utf8 tools/qpsk_rf_rx.py `
    --iq-file data/raw/rf001/rf001a_common_clock_001/tx_waveform.cs8 `
    --iq-format cs8 `
    --truth-metadata data/raw/rf001/rf001a_common_clock_001/tx_metadata.json `
    --report '<new unique path outside Git>\rf001a_tx_offline_verify.json'
```

Require the receiver report to contain `crc_valid_packets = 100`, `exact_packets = 100`, no missing packets and no duplicates.

Require:

```text
canonical waveform = PASS
hardware-format cs8 = PASS
offline hardware-format roundtrip = 100/100 exact
TX waveform path = data/raw/rf001/rf001a_common_clock_001/tx_waveform.cs8
TX waveform size = 17667656 bytes
TX waveform SHA256 = 75f3fa39bfa88b623b7e4e5a02e3a80b52185007397ea56ceaacc13353974b2
sample count = 8833828 complex samples
expected duration = 1.1042285 s
```

If any value differs, if RX is not ready, or if the RX capture window has ended, do not transmit and STOP.

Only after every precondition passes may the user provide the separate exact phrase `AUTHORIZE RF TX`.

## 3. One authorized TX execution

After the separate RED authorization and the live `RX READY FOR TX = YES` confirmation, create a new unique local evidence directory outside Git. Refuse an existing directory and never overwrite earlier evidence.

Use this single finite command:

```text
hackrf_transfer.exe
-d 000000000000000097c063dc323b97d3
-t data/raw/rf001/rf001a_common_clock_001/tx_waveform.cs8
-f 1400000000
-s 8000000
-n 8833828
-x 20
-a 0
-p 0
-B
```

Run it once, synchronously, and preserve the exact process exit code:

```powershell
$txRunId = '{0}_{1}' -f (Get-Date -Format 'yyyyMMdd_HHmmss'), ([guid]::NewGuid().ToString('N').Substring(0, 8))
$txEvidenceRoot = Join-Path ([Environment]::GetFolderPath('MyDocuments')) 'SDR_Rover_TX_Evidence'
$txEvidenceDirectory = Join-Path $txEvidenceRoot "RF001A_OTA_TX_001_$txRunId"
if (Test-Path -LiteralPath $txEvidenceDirectory) { throw "TX evidence directory already exists: $txEvidenceDirectory" }
New-Item -ItemType Directory -Path $txEvidenceDirectory -ErrorAction Stop | Out-Null

$hackrfTransfer = 'C:\Users\user\Tools\HackRF\Library\bin\hackrf_transfer.exe'
$waveformPath = (Resolve-Path -LiteralPath 'data/raw/rf001/rf001a_common_clock_001/tx_waveform.cs8').Path
$stdoutPath = Join-Path $txEvidenceDirectory 'hackrf_transfer.stdout.log'
$stderrPath = Join-Path $txEvidenceDirectory 'hackrf_transfer.stderr.log'
$txArguments = @(
    '-d', '000000000000000097c063dc323b97d3',
    '-t', $waveformPath,
    '-f', '1400000000',
    '-s', '8000000',
    '-n', '8833828',
    '-x', '20',
    '-a', '0',
    '-p', '0',
    '-B'
)

$txStartedAt = [DateTimeOffset]::Now
$txProcess = Start-Process -FilePath $hackrfTransfer -ArgumentList $txArguments `
    -RedirectStandardOutput $stdoutPath -RedirectStandardError $stderrPath `
    -PassThru -Wait -WindowStyle Hidden
$txFinishedAt = [DateTimeOffset]::Now
$txProcess.Refresh()
$txExitCode = $txProcess.ExitCode
```

Immediately write the exit code, process ID, timestamps, duration, command parameters, waveform size and waveform SHA256 to a new JSON metadata file in `$txEvidenceDirectory`. Preserve complete stdout and stderr.

Inspect every buffer-statistics line. Record:

```text
TX start time =
TX end time =
TX PID =
TX exit code =
TX underruns =
USB errors =
RF TX STOPPED =
YES / NO
```

Do not infer zero from a missing counter. Use `NOT_REPORTED` when no counter exists. Any nonzero intermediate or final underrun/error line remains evidence even if a later line reports zero.

Set `RF TX STOPPED = YES` only after the finite process exits. Do not start a second burst for any reason. Do not retry automatically.

## 4. Final TX report

```text
TASK_ID =
RF001A_OTA_TX_001

RED AUTHORIZATION =
AUTHORIZE RF TX / MISSING

RX READY FOR TX =
YES / NO

TX SERIAL =

TX WAVEFORM SHA256 =

TX START TIME =

TX END TIME =

TX EXIT CODE =

TX UNDERRUNS =

USB ERRORS =

RF TX STOPPED =
YES / NO

BURSTS TRANSMITTED =
0 / 1

RF TX =
0
```

At report time, `RF TX = 0` means no transmission process remains active.

## 5. Prohibited actions

Do not transmit before the separate exact RED authorization. Do not inherit approval from the RX task. Do not use repeat mode, start a second burst, change frequency, gains, clock configuration, waveform, firmware, CPLD, Zadig or USB drivers. Do not commit or push from this task.