# Nordic Ski GPS Logger

## Description

Removable cold\-weather cross\-country ski logger with 10 Hz dual\-band GNSS, BLE heart\-rate strap recording, barometric altitude, onboard storage, and magnetic USB charging/data\.

## Project Details

- **Owner:** aittam28
- **Created:** 9/27/2026
- **Last Updated:** 9/27/2026
- **Visibility:** Public

## Key Components

### D1 — [USBLC6\-2SC6](https://flux.ai/vasy_skral/usblc6-2sc6~g1b.md)

- Manufacturer Part Number: USBLC6\-2SC6
- Symbol Style: parametric\-v1
- Functional Group: USB D1 DATA PROTECTION
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Protection
- Manufacturer Name: STMicroelectronics
- Role Details: Protects USB D\+ and D\- at exposed magnetic contacts
- Datasheet URL: https://www\.st\.com/content/ccc/resource/technical/document/datasheet/06/1d/48/9c/6c/20/4a/b2/CD00050750\.pdf/files/CD00050750\.pdf/jcr:content/translations/en\.CD00050750\.pdf
- Role: USB ESD Protection
- LCSC Part Number: C7519

**Pins:**
- GND [pin 2]
- I/O1 [pin 6]
- I/O1 [pin 1]
- I/O2 [pin 3]
- I/O2 [pin 4]
- VBUS [pin 5]

### D2 — [SMF5\.0A](https://flux.ai/lcsc/smf5p0a~bz6b.md)

- Package or Case Code: SOD\-123FL\_L2\.8\-W1\.8\-LS3\.6\-RD
- JLCPCB Part Class: Extended Part
- Functional Group: USB D1 DATA PROTECTION
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2990427\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=T1kIXgFeT1NaU1RXQFBbUlUHT1cKU1NXFVBeX1VSTlAxVlNRTlBbUVFXRldaXzsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- LCSC Part Number: C2990427
- Diode Type: Schottky Diode
- Part Type: TVS
- Max Reverse Voltage: 5V
- Manufacturer Name: Liown\(里阳半导体\)
- Role: VBUS ESD Protection
- Role Details: Clamps transients at exposed 5 V magnetic contact
- Manufacturer Part Number: SMF5\.0A
- Forward Voltage: 0\.45V to 0\.55V \(at 1A\)V

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### F1 — [SMD050F\-2](https://flux.ai/adrian95/smd050f-2.md)

- Datasheet URL: https://www\.littelfuse\.com/assetdocs/littelfuse\-ptc\-smd\-datasheet?assetguid=e664881a\-0c68\-4836\-928b\-7ed2f0c2a6da
- Part Type: Circuit Protection Devices
- Manufacturer Part Number: SMD050F\-2
- Role Details: 500 mA hold USB input protection ahead of charger
- Mount: Surface Mount
- Functional Group: USB D1 DATA PROTECTION
- Manufacturer Name: Littelfuse
- Role: Input Overcurrent Protection
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- \~ [pin 2]
- \~ [pin 1]

### J1 — [U\.FL\-R\-SMT\(01\)](https://flux.ai/adrian95/upfl-r-smt01~ap.md)

- Role: External RF Test
- Part Type: Connector
- Functional Group: GNSS U2 DUAL BAND
- Datasheet URL: https://mm\.digikey\.com/Volume0/opasdata/d220001/medias/docus/2607/UFL%20Series\.pdf
- Manufacturer Name: Hirose Electric Co Ltd
- Manufacturer Part Number: U\.FL\-R\-SMT\(01\)
- Role Details: Selectable external antenna and conducted RF comparison path for EVT
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- GND [pin 1]
- GND [pin 2]
- SIG [pin 3]

### J2 — [SM03B\-GHS\-TB\(LF\)\(SN\)](https://flux.ai/lcsc/sm03b-ghs-tblfsn~j14u.md)

- LCSC Part Number: C514175
- Role Details: Protected cold\-rated 1S LiPo: BAT\+, BAT\-, and 10k NTC lead; two additional terminals are mechanical shell pads
- Symbol Style: parametric\-v1
- Part Type: Wire To Board / Wire To Wire Connector
- Functional Group: POWER U5 CHARGER PATH
- Pitch: 0\.049" \(1\.25mm\)
- License: https://creativecommons\.org/licenses/by/4\.0/
- Positions: 3
- Package or Case Code: CONN\-TH\_SM03B\-GHS\-TB\-LF\-SN
- Manufacturer Part Number: SM03B\-GHS\-TB\(LF\)\(SN\)
- JLCPCB Part Class: Extended Part
- Connector Type: Header
- Manufacturer Name: JST
- Datasheet URL: https://www\.lcsc\.com/datasheet/C514175\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=T1kIXgFeT1NaU1RXQFBbUlUHT1cKU1NXFVBeX1VSTlAxVlNeR1JcVFJWQVNWXjsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- Role: Battery Connector
- Rows: 1
- Gender: Female

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]

### J3 — [FTSH\-103\-01\-L\-DV](https://flux.ai/cherepanyadima/ftsh-103-01-l-dv~u9.md)

- Manufacturer Name: Samtec
- Manufacturer Part Number: FTSH\-103\-01\-L\-DV
- Datasheet URL: https://suddendocs\.samtec\.com/catalog\_english/ftsh\_smt\.pdf
- Functional Group: DEBUG U1 SWD
- Role: SWD Debug
- Part Type: Connector
- Role Details: Compact 2x3 SWD interface: VREF, SWDIO, SWCLK, RESET, GND; one spare pin

**Pins:**
- 01 [pin 01]
- 02 [pin 02]
- 03 [pin 03]
- 04 [pin 04]
- 05 [pin 05]
- 06 [pin 06]

### LED1 — [NH\-B2020RGBA\-HF](https://flux.ai/adrian95/nh-b2020rgba-hf~38o.md)

- Role: Status Indicator
- Functional Group: UI U1 BUTTON LED
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Low\-duty low\-current common\-anode RGB status LED behind light pipe
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2874116\.pdf
- Part Type: LED
- Manufacturer Name: Foshan NationStar Optoelectronics
- LCSC Part Number: C2874116
- Manufacturer Part Number: NH\-B2020RGBA\-HF

**Pins:**
- \- [pin 1]
- \- [pin 4]
- \- [pin 2]
- \+ [pin 3]

### SW1 — [PTS815](https://flux.ai/vasy_skral/pts815~6b.md)

- Part Type: Switch
- Role Details: Top\-side enclosure\-actuated glove button; place outside GNSS antenna keepout
- Manufacturer Name: C&K
- Manufacturer Part Number: PTS815 SJM 250 SMTR LFS
- Role: User Button
- Datasheet URL: https://www\.ckswitches\.com/media/2728/pts815\.pdf
- Functional Group: UI U1 BUTTON LED

**Pins:**
- \~1 [pin 1]
- \~2 [pin 2]
- \~3 [pin 3]
- \~4 [pin 4]

### TP1 — [TestPoint\_Pad\_1\.0x1\.0mm](https://flux.ai/adrian95/testpointpad10x10mm~77t.md)

- Role Details: Recessed hard\-gold PCB pad: VBUS; enclosure and cable provide keying
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role: Magnetic USB Contact
- Functional Group: USB D1 DATA PROTECTION
- Part Type: Connector

**Pins:**
- 1 [pin 1]

### TP2 — [TestPoint\_Pad\_1\.0x1\.0mm](https://flux.ai/adrian95/testpointpad10x10mm~77t.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: USB D1 DATA PROTECTION
- Role Details: Recessed hard\-gold PCB pad: USB D\-; keyed cable assumption
- Part Type: Connector
- Role: Magnetic USB Contact

**Pins:**
- 1 [pin 1]

### TP3 — [TestPoint\_Pad\_1\.0x1\.0mm](https://flux.ai/adrian95/testpointpad10x10mm~77t.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Role Details: Recessed hard\-gold PCB pad: USB D\+; keyed cable assumption
- Role: Magnetic USB Contact
- Part Type: Connector
- Functional Group: USB D1 DATA PROTECTION

**Pins:**
- 1 [pin 1]

### TP4 — [TestPoint\_Pad\_1\.0x1\.0mm](https://flux.ai/adrian95/testpointpad10x10mm~77t.md)

- Role: Magnetic USB Contact
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: USB D1 DATA PROTECTION
- Role Details: Recessed hard\-gold PCB pad: GND; outermost contact and keyed cable assumption
- Part Type: Connector

**Pins:**
- 1 [pin 1]

### U1 — [MDBT50Q\-1MV2](https://flux.ai/jecstronic/mdbt50q-1mv2~4xq.md)

- Part Type: Module
- Datasheet URL: https://www\.raytac\.com/download/index\.php?index\_id=43
- Manufacturer Name: Raytac
- Manufacturer Part Number: MDBT50Q\-1MV2
- Role: Compute and BLE
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: MCU U1 BLE COMPUTE
- Role Details: nRF52840 module; preserve native USB, SWD, QSPI, UART, I2C, and RF antenna keepout

**Pins:**
- D\- [pin 34]
- D\+ [pin 35]
- DCCH [pin 31]
- GND [pin 55]
- GND [pin 33]
- GND [pin 1]
- GND [pin 2]
- GND [pin 15]
- P0\.00/XL1 [pin 17]
- P0\.01/XL2 [pin 18]
- P0\.02/AIN0 [pin 11]
- P0\.03/AIN1 [pin 9]
- P0\.04/AIN2 [pin 20]
- P0\.05/AIN3 [pin 21]
- P0\.06 [pin 22]
- P0\.07/TRACECLK [pin 23]
- P0\.08 [pin 24]
- P0\.09/NFC1 [pin 52]
- P0\.10/NFC2 [pin 54]
- P0\.11/TRACEDATA2 [pin 27]
- P0\.12/TRACEDATA1 [pin 29]
- P0\.13 [pin 37]
- P0\.14 [pin 36]
- P0\.15 [pin 39]
- P0\.16 [pin 38]
- P0\.17 [pin 41]
- P0\.18/\~RESET [pin 40]
- P0\.19 [pin 42]
- P0\.20 [pin 44]
- P0\.21 [pin 43]
- P0\.22 [pin 46]
- P0\.23 [pin 45]
- P0\.24 [pin 48]
- P0\.25 [pin 49]
- P0\.26 [pin 19]
- P0\.27 [pin 16]
- P0\.28/AIN4 [pin 13]
- P0\.29/AIN5 [pin 10]
- P0\.30/AIN6 [pin 14]
- P0\.31/AIN7 [pin 12]
- P1\.00/TRACEDATA0 [pin 47]
- P1\.01 [pin 61]
- P1\.02 [pin 50]
- P1\.03 [pin 60]
- P1\.04 [pin 56]
- P1\.05 [pin 59]
- P1\.06 [pin 57]
- P1\.07 [pin 58]
- P1\.08 [pin 25]
- P1\.09/TRACEDATA3 [pin 26]
- P1\.10 [pin 3]
- P1\.11 [pin 4]
- P1\.12 [pin 5]
- P1\.13 [pin 6]
- P1\.14 [pin 7]
- P1\.15 [pin 8]
- SWDCLK [pin 53]
- SWDIO [pin 51]
- VBUS [pin 32]
- VDD [pin 28]
- VDDH [pin 30]

### U2 — [MAX\-F10S\-00B](https://flux.ai/cherepanyadima/max-f10s-00b.md)

- Manufacturer Name: u\-blox
- Datasheet URL: https://www\.snapeda\.com/parts/MAX\-F10S\-00B/u\-blox/datasheet/
- Manufacturer Part Number: MAX\-F10S\-00B
- Role: GNSS Receiver
- Role Details: Dual\-band L1/L5 10 Hz receiver; place beside antenna feed and preserve RF ground/keepout guidance
- Functional Group: GNSS U2 DUAL BAND
- Symbol Style: parametric\-v1
- Part Type: Integrated Circuit

**Pins:**
- EXTINT [pin 5]
- GND\_1 [pin 1]
- GND\_2 [pin 10]
- GND\_3 [pin 12]
- LNA\_EN [pin 13]
- RESET\_N [pin 9]
- RF\_IN [pin 11]
- RXD [pin 3]
- SAFEBOOT\_N [pin 18]
- SCL [pin 17]
- SDA [pin 16]
- TIMEPULSE [pin 4]
- TXD [pin 2]
- V\_BCKP [pin 6]
- V\_IO [pin 7]
- VCC [pin 8]
- VCC\_RF [pin 14]
- VIO\_SEL [pin 15]

### U3 — [BMP581](https://flux.ai/adrian95/bmp581~4uy.md)

- Role Details: Pressure and temperature logging near hydrophobic vent
- Functional Group: SENSOR U3 BAROMETER
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: Bosch Sensortec
- Role: Barometric Sensor
- Datasheet URL: https://www\.bosch\-sensortec\.com/media/boschsensortec/downloads/datasheets/bst\-bmp581\-ds004\.pdf
- Manufacturer Part Number: BMP581
- Part Type: Sensor
- Symbol Style: parametric\-v1

**Pins:**
- CSB [pin 6]
- INT [pin 7]
- SCK [pin 2]
- SDI [pin 4]
- SDO [pin 5]
- VDD [pin 10]
- VDDIO [pin 1]
- VSS [pin 8]
- VSS [pin 9]
- VSS [pin 3]

### U4 — [W25Q256JVEIM](https://flux.ai/lcsc/w25q256jveim~eppx.md)

- LCSC Part Number: C2641261
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: W25Q256JVEIM
- Package or Case Code: WSON\-8\_L6\.0\-W8\.0\-P1\.27\-BL\-EP
- Functional Group: MEMORY U4 QSPI FLASH
- Manufacturer Name: WINBOND\(华邦\)
- Role Details: 32 MB QSPI NOR flash for compact session records
- Role: Logging Storage

**Pins:**
- \~\{CS\} [pin 1]
- CLK [pin 6]
- DI\(IO0\) [pin 5]
- DO\(IO1\) [pin 2]
- EP [pin 9]
- GND [pin 4]
- HOLD\#orRESET\#\(IO3\) [pin 7]
- VCC [pin 8]
- WP\#\(IO2\) [pin 3]

### U5 — [BQ24074RGTR](https://flux.ai/vasyl/bq24074rgtr~yke.md)

- Manufacturer Part Number: BQ24074RGTR
- License: https://creativecommons\.org/licenses/by/4\.0/
- Role: Battery Charger and Power Path
- Manufacturer Name: Texas Instruments
- Datasheet URL: https://www\.ti\.com/general/docs/suppproductinfo\.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww\.ti\.com%2Flit%2Fgpn%2Fbq24074
- Functional Group: POWER U5 CHARGER PATH
- Part Type: Battery Chargers
- Role Details: 300 mA baseline charge; protected 1S LiPo; NTC cold\-charge inhibit; system power path

**Pins:**
- \~CE [pin 4]
- \~CHG [pin 9]
- \~PGOOD [pin 7]
- BAT\_2 [pin 2]
- BAT\_3 [pin 3]
- EN1 [pin 6]
- EN2 [pin 5]
- EXP [pin 17]
- ILIM [pin 12]
- IN [pin 13]
- ISET [pin 16]
- ITERM [pin 15]
- OUT\_10 [pin 10]
- OUT\_11 [pin 11]
- TMR [pin 14]
- TS [pin 1]
- VSS [pin 8]

### U6 — [TPS62840DLCR](https://flux.ai/cherepanyadima/tps62840dlcr.md)

- Package or Case Code: TO
- Functional Group: POWER U6 3V3 BUCK
- Manufacturer Part Number: TPS62840DLCR
- Datasheet URL: https://www\.ti\.com/general/docs/suppproductinfo\.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww\.ti\.com%2Flit%2Fgpn%2Ftps62840
- Role Details: Supplies approximately 30 mA typical and 80 mA noncoincident peak budget; 750 mA rated for margin
- Part Type: Integrated Circuit
- Role: 3V3 Regulation
- Manufacturer Name: Texas Instruments

**Pins:**
- EN [pin 4]
- GND [pin 1]
- MODE [pin 3]
- STOP [pin 6]
- SW [pin 7]
- VIN [pin 2]
- VOS [pin 8]
- VSET [pin 5]

### U7 — [TPS22919DCKT](https://flux.ai/vasy_skral/tps22919dckt~rom.md)

- Datasheet URL: https://www\.ti\.com/general/docs/suppproductinfo\.tsp?distId=10&gotoUrl=http%3A%2F%2Fwww\.ti\.com%2Flit%2Fgpn%2Ftps22919
- Package or Case Code: 6\-TSSOP, SC\-88, SOT\-363
- Part Type: Integrated Circuit
- Role Details: Firmware controlled GNSS rail isolation for standby and recovery testing
- Manufacturer Part Number: TPS22919DCKT
- Functional Group: GNSS U2 DUAL BAND
- Manufacturer Name: Texas Instruments
- Role: GNSS Power Switch

**Pins:**
- GND
- IN
- ON
- QOD
- VOUT

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/aittam28/nordic\-ski\-gps\-logger\~7b](https://flux.ai/aittam28/nordic-ski-gps-logger~7b).*

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*Generated from [https://flux\.ai/aittam28/nordic\-ski\-gps\-logger\~7b](https://flux.ai/aittam28/nordic-ski-gps-logger~7b)*