diff --git a/README.md b/README.md index 4cec023..cf6f69f 100644 --- a/README.md +++ b/README.md @@ -1,57 +1,42 @@ # BUTCube +Modules: +- Solar panels (XY, Z) (not in stack) +- EPS +- Flight Computer +- Mission computer +- Communication +- Sun sensor module (not in stack) +- ? Attitude control +- Access port module (not in stack) -# Solar cells - -Digi-key filter: https://www.digikey.nl/products/en?FV=-5|23585 - -Calculations for space are calculated with 1 mm space between panels -In center of panel there should be attitude determination module with minimal size od 25mm x 25mm -All calculation are only for one side of satelite +# Solar panels +## Solar cells #### SM141K04L - Link: https://www.digikey.nl/short/fvpwbf4h -- Panel count: 10 (2S 5P) -- Maximal power: 1.23 W -- Voltage: 4.46 V -- Dimensions: 29 x 23 mm (89 x 95 mm) -- Weight: 3g (30g) -- Configuration: 4 x 3 -- Price (for 1 side): 28 € (750 CZK) - -#### KXOB25-05X3F -- Link: https://www.digikey.nl/short/hdrrmtq3 -- Panel count: 32 (4S 8P) +- Panel count: 8 (2S 4P) - Maximal power: 0.98 W -- Voltage: 6.68 V -- Dimensions: 23 x 8 mm (95 x 89 mm) -- Weight: 0.5g (17g) -- Configuration: 10 x 4 -- Price (for 1 side): 47 € (1229 CZK) -- + Reflow solderable - -#### SM141K06LV -- Link: https://www.digikey.nl/short/d80rrj7t -- Panel count: 6 (2S 3P) -- Maximal power: 1.10 W -- Voltage: 6.7 V -- Dimensions: 45 x 22 mm (91 x 91 mm) -- Weight: 3g (18g) -- Configuration: 2V 2H 2V -- Price (for 1 side): 27 € (720 CZK) +- Voltage: 4.46 V (MPPT) +- Dimensions: 29 x 23 mm +- Weight: 3g (24g) +- Price (for 1 side): 28 € (750 CZK) #### SM141K04LV - Link: https://www.digikey.cz/short/r589mmbj - Panel count: 8 (2S 4P) - Maximal power: 0.98 W -- Voltage: 5.52 V -- Dimensions: 45 x 15 mm (81 x 95 mm) +- Voltage: 4.46 V (MPPT) +- Dimensions: 45 x 15 mm - Weight: 2.5g (20g) -- Configuration: 2V 4H 2V - Price (for 1 side): 28 € (750 CZK) ## Solar module -- PCB with size cca 96x96 mm -- In center of module is hole for another module (40x40 mm without corners) +- Two sizes of solar panel PCBs + - Z - 100x100 mm with cutouts in corners for rails + - X,Y - 100x83 +- In center of module is hole for another module + - Approximate size of module is 46x30 mm + - Mounting to frame is via 4 bolts in corners of board - Integrated components: Optodiode, temperature measuring IC ## Sensors @@ -59,15 +44,85 @@ All calculation are only for one side of satelite - Photo diode: - VEMD5510C - 550nm (450-750) - visible - VEMD5060X - 800nm (500-1000) - visible + IR - - VEMD5160X - 850nm (750-950) - IR + - VEMD5160X - 850nm (750-950) - IR (used) - ADC for photodiode: ADS7142 +# Cables +- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3165/1528-1733-ND/6193585 +- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3167/1528-1735-ND/6193587 +- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3168/1528-1736-ND/6193588 +- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3164/1528-1732-ND/6193584 + +- 30AWG resistance 0.3R per meter +- Length in CubeSat cca 10-15 cm +- Power loss in cables is 0.5mW in peek (0.05% per solar module) +- Similar power loss will be at cable connectors + +# Stack connector +- [https://cz.mouser.com/ProductDetail/200-SSQ12002TD] +- 2x20 pins +- Limits board to thickness of 1mm or less +- Board spacing: 8.51 mm + +# EPS +- Two identical modules on one board +- Both connected to stack connector +- Other board could be connected to both or one of then + - Power oring must be solved +- Connected to main CAN + +## Power output +- 3 regulated and monitored power rails - 1V8, 3V3, 5V + - Output regulator - TPS63002DRCR + - 0.8A (boost) up to 1.2A (buck) output + - 2.2 uH coil +- 1 unregulated output of battery, monitored +- Monitoring via current sensors (INA??) + +## Battery +- Limit for CubeSat is 50Wh +- Suggested battery has form factor 21700 +- One battery per EPS +- Battery is mounted in battery holder + - Keystone 1122 - 1122 + - Probably additional fixation is requested +- Selected battery - https://www.conrad.cz/p/samsung-inr21700-50e-specialni-akumulator-21700-flat-top-li-ion-akumulator-36-v-4900-mah-2114678 + - 3.6V, 4900mAh, 17.64Wh + - EPS module has around 35Wh (well in limit) + +## Battery heating +- https://www.ges.cz/cz/odl-20r81-GES06914579.html +- https://www.ges.cz/cz/odl-53r1-GES06914581.html +- https://www.gme.cz/odporovy-drat-odp-kan02-3m +- https://www.gme.cz/odporovy-drat-odp-kon03-3m + +- Heating should be designed for power around 1-4W +- With 5.4R/m and battery input source (3.7V) length of wire for 2W heating should be around 1.2m (current 0.5A) + - 0.5A is probably to much, values around 0.2A are better -> 1W heating +- For regulation could be used power switch with constant current regulation + +# Access port module +Connectors: +- USB-C + - data connected to mission computer or flight computer + - power connected to EPS for battery charging +- 2x SWD port for programing and debugging of Flight and Mission computer +- main CAN bus connector +- UART debug port + +- Realized as stack of two PCB boards + - Front acts only as cover for connectors + - Connectors are mounted on rear board + - Connectors are accessible via cutouts in frontz board + - Rear board is mounted to front via column spacers + # Other parts: - LTC4415 - Dual ideal diode with ORing -- MAX16171 +- MAX16171 - Ideal Diode Controller with Reverse-Current Protection - BQ25798 - solar battery charger with dual-input selector and MPPT, I2C, https://www.ti.com/product/BQ25798 - BAT54W-G - Low drop shottky diode, solar blocking diode +- BQ27421YZFT-G1A - Fuel gauge - - - +# Digikey orders +https://www.digikey.cz/short/8nmn4tr3 +https://www.digikey.cz/short/d4n94tbz