SSTV - portapack-mayhem/mayhem-firmware GitHub Wiki
SSTV TX transmits Slow Scan Television images from .BMP files stored on the SD card. The signal is transmitted as FM audio tones in the standard SSTV frequency range (1,500โ2,300 Hz).
Controls
- File โ Selects the
.BMPfile to transmit from thesstv/directory on the SD card. - Mode โ Selects the SSTV transmission mode. Default: Scottie 2.
- Frequency, Gain, AMP โ Standard RF controls. Default gain: 12 dB.
- โถ โ Starts transmission. A progress bar shows the current scanline.
Supported Modes
| Mode | VIS Code | Lines | ยตs/pixel |
|---|---|---|---|
| Scottie 1 | 60 | 256 | 432.0 |
| Scottie 2 (default) | 56 | 256 | 275.2 |
| Scottie DX | 76 | 256 | 1080.0 |
| Martin 1 | 44 | 256 | 457.6 |
| Martin 2 | 40 | 256 | 228.8 |
| SC2-180 | 55 | 256 | 734.4 |
All modes transmit 320 pixels per line and 256 lines (320ร256 total).
Image Requirements
- Format: 24-bit uncompressed BMP (
.bmp) - Size: exactly 320ร256 pixels
- Location:
sstv/directory on the SD card (lowercase)
Images that do not match the required resolution will produce incorrect output.
RF Parameters
| Parameter | Value |
|---|---|
| Sample rate | 3.072 MSps |
| Baseband bandwidth | 1.75 MHz (fixed) |
| Frequency step | 10 kHz |
Settings Persistence
Settings are saved to tx_sstv.ini.