Frequencies
| Band | Frequency | Use | Modulation |
|---|---|---|---|
| VHF | 145.825 MHz | APRS | AFSK 1200 bps / AX.25 |
| UHF | 437.375 MHz | CW beacon | CW |
| UHF | 437.375 MHz | Downlink of HK, images and APRS logs | GMSK 4800 bps / AX.25 |
The callsign is JS1YNI
GMSK downlink packet
AX.25 UI frame; the first 22 bytes are a common header
| byte | Content | Value |
|---|---|---|
| 0–6 | Destination callsign + SSID | JS1YMY + 0x30 |
| 7–13 | Source callsign + SSID | JS1YNI + 0x30 |
| 14 | Control | 0x3E |
| 15 | PID | 0xF0 |
| 16 | SAT ID | 0x53 |
| 17 | PCKT ID | 0x11 data |
| 18 | Reserve | 0xFF |
| 19–21 | Packet sequence number | |
| 22– | Payload | 64 byte |
| last 2 bytes | CRC |
An address management packet sends the start address of each data area
| Area | Start address |
|---|---|
| FLAG | 0x00040000 |
| Reserved commands | 0x00050000 |
| SATLOG | 0x00060000 |
| HK | 0x00080000 |
| CW | 0x03F10000 |
| High-rate HK | 0x041A0000 |
| APRS received messages | 0x05B01000 |
| APRS mission log | 0x05B20000 |
| Mission PIC log | 0x05B50000 |
| SCAM thumbnails | 0x05B61000 |
| ECAM thumbnails | 0x05EBA000 |
| SCAM images | 0x06213000 |
| ECAM images | 0x0640E000 |
| PD mission log | 0x06A10000 |
HK format
64 byte
| byte | Item | Note |
|---|---|---|
| 0 | Header | 0x33 |
| 1, 2, 3 | sec, min, hour | On-board time |
| 4–5 | day | |
| 6–7 | +X Temp | |
| 8–9 | −X Temp | |
| 10–11 | +Y Temp | |
| 12–13 | −Y Temp | |
| 14–15 | +Z Temp | |
| 16–17 | −Z Temp | |
| 18–19 | BPB Temp | |
| 20–21 | −X Voltage | |
| 22–23 | +Y Voltage | |
| 24–25 | −Y Voltage | |
| 26–27 | +Z Voltage | |
| 28–29 | −Z Voltage | |
| 30–34 | −X, +Y, −Y, +Z, −Z Current | 1 byte each |
| 35 | Battery Temp | |
| 36 | Battery Voltage | |
| 37–38 | Battery Current | |
| 39 | FAB RAW Voltage | |
| 40–41 | FAB RAW Current | |
| 42 | SRC Voltage | |
| 43–44 | SRC Current | |
| 45 | Kill Status | Upper 4 bit FAB, lower 4 bit MAIN |
| 46 | RESET RAW Voltage | |
| 47, 48 | 3V3#1, 3V3#2 Current | |
| 49, 50 | unreg#1, unreg#2 Current | UHF-COM, DEPANT |
| 51 | 5V Current | |
| 52–53 | RESET_SW_STATUS | See table below |
| 54 | 1h RESET Counter | |
| 55 | RSSI | |
| 56 | COM Temp | |
| 57 | Sequence Counter | |
| 58 | CMD Counter | |
| 59 | MIS ACK | |
| 60 | APRS Flash Remain | |
| 61 | Current Mission | |
| 62 | MIS COUNT | Mission execution count |
| 63 | CRC | XOR of bytes 0–62 |
Bit assignment of RESET_SW_STATUS
| bit | byte 52 | byte 53 |
|---|---|---|
| 7 | RESET_RAW_V_MON | DCDC_3V3_2 |
| 6 | LCL_UHF_COM | LCL_COMPIC |
| 5 | LCL_5V0 | LCL_MAINPIC |
| 4 | DCDC_FAB | — |
| 3 | LCL_DEPANT | — |
| 2 | LCL_3V3_2 | — |
| 1 | LCL_FAB | — |
| 0 | DCDC_5V0 | — |
APRS
| Mode | Operation |
|---|---|
| Digipeat | Re-transmits received messages as they are over APRS |
| User message | Sends a specified message over APRS |
| User query | Responds to a received message |
| Transmit | Sends a specified message from the satellite |
Received messages are stored on board and downlinked over UHF