SPACEDOS01A - Engineering Model
The SPACEDOS01 variant is compatible with MLAB kit system suitable for engineering workflows like firmware development and testing.
Main technical parameters
- Dissipated Energy range: from 200 keV to 9 MeV
- Energy Resolution: < 50 keV
- Temperature Stability: from -50 ℃ to +50 ℃ within error +50 keV
- Used Sensor: HAMAMATSU S11773-02 (PIN diode 5 x 5 x 0.5 mm3)
Physical dimensions
Electrical interface
The connector is a 2.54mm pitch pin header.
| Signal | Description |
|---|---|
| PC7 | Universal IO pin |
| PC3 | Universal IO pin |
| RX0 | RS232 Receive (3.3 V) |
| TX0 | RS232 Transmit (3.3 V) |
| RST# | Reset (trough capacitor) |
| GND | Ground |
| 3V3 | Power supply +3.3 V |
| 5V | Internally connected to +3.3 V |
Power consumption: 2.6 mA from 3.3 V
Communication protocol
Sample of output data
#Cvak...
#Hmmm...
$DPSD,00000f08,7fc5,002f,0000,0000,0001,0000,0000,0000,0000,0100
$HKSD,244,3848,32778,254,0,0,32709,47,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
$BESD,0004,0000010e,00000000,00000000,00000001,00000000,00000000,00000000,00000000
$ADSD,000000de,00000003,00000000,0000011d,00000000,00000000
SPACEDOS sends $DPSD, $HKSD, and $BESD messages each cca 15 seconds. $ADSD message is sent once per day.
Communication speed is 2400 baud.
Power On
#Cvak…
A message saying ‘hello’ after turning the device on.
Initiation complete
#Hmmm...
Initiation of the SPACEDOS HW is done. Initiation is completed up to one second after turning on.
DPSD - SpaceDos Data Payload message
$DPSD, <uptime>, <noise channel>, <0.1 MeV>, <0.14 MeV>, <0.21 MeV>, <0.33 MeV>, <0.66 MeV>, <1.68 MeV>, <4.72 MeV>, <'>=9 MeV'>, <DC offset>
| Value | Length | Type | Note |
|---|---|---|---|
| $DPSD | 5 B | Char | Header |
| uptime | 4 B | Hex | Time from power on |
| noise channel | 2 B | Hex | this channel contains noise |
| 0.1 MeV | 2 B | Hex | number of particles with absorbed energy above 0.1 MeV |
| … | … | … | |
| ’>=9’ MeV | 2 B | Hex | Overrange particles |
| DC offset | 2 B | Hex | Offset of ADC |
These messages should be stored for a long time and transmitted to the ground in a batch.
Minimal data payload (without time mark) is 18 B per 15 s => 103680 B per day
HKSD - SpaceDos HouseKeeping message
$HKSD, <measurement No.> , <uptime>, <filter suppressions>, <position of the 1-st channel>, <1-st ch.>, <2-nd ch.>, <3-rd ch.>,...
This is a packet with housekeeping information. Transmission of this packet is done besides other experiments’ housekeeping data. The total length of this packet should be shortened.
| Value | Range | type | Note |
|---|---|---|---|
| $HKSD | fix | Char | Header |
| measurement No. | 0..65535 | Dec | |
| uptime | 0..4294967295 | Dec | |
| filter suppressions | 0..65535 | Dec | Number of usage of a digital filter for double peak suppression |
| position of the 1-st channel | 0..511 | Dec | |
| 1-st ch. | 0..65535 | Dec | Number of events in 1st ch. |
| 2-nd ch. | 0..65535 | Dec | Number of events in 2nd ch. |
| … | … | ||
| 50-th ch. | 0..65535 | Dec | Number of events in 50th ch. |
BESD - SpaceDos BEacon message
$BESD,<counter>, <0.1 MeV>, <0.14 MeV>, <0.21 MeV>, <0.33 MeV>, <0.66 MeV>, <1.68 MeV>, <4.72 MeV>, <'>=9 MeV'>
This message contains cumulative data for beacon transmission.
| Value | Length | Type | Note |
|---|---|---|---|
| $BESD | 5 B | Char | Header |
| counter | 2 B | Hex | Number of the beacon message |
| 0.1 MeV | 2 B | Hex | number of particles with absorbed energy above 0.1 MeV |
| 0.14 MeV | 2 B | Hex | number of particles with absorbed energy above 0.14 MeV |
| … | … | … | |
| ’>=9’ MeV | 2 B | Hex | Overrange particles |
ADSD - SpaceDos Almanac Data message
$ADSD, <0.1 MeV 1 day old>, <0.14 MeV one day old>, <0.66 MeV one day old>, <0.1 MeV two days old>, <0.14 MeV two days old>, <0.66 MeV two days old>
This message contains two days’ old data for beacon transmission purposes.
| Value | Length | Type | Note |
|---|---|---|---|
| $ADSD | 5 B | Char | Header |
| 0.1 MeV one day old | 4 B | Hex | number of particles with absorbed energy above 0.1 MeV one day before |
| 0.14 MeV one day old | 4 B | Hex | number of particles with absorbed energy above 0.14 MeV one day before |
| 0.66 MeV one day old | 4 B | Hex | number of particles with absorbed energy above 0.66 MeV one day before |
| 0.1 MeV two days old | 4 B | Hex | number of particles with absorbed energy above 0.1 MeV two days before |
| 0.14 MeV two days old | 4 B | Hex | number of particles with absorbed energy above 0.14 MeV two days before |
| 0.66 MeV two days old | 4 B | Hex | number of particles with absorbed energy above 0.66 MeV two days before |