GDP Glacier Monitor - Hardware - part of the glacsweb.org project at The University of Southampton
├── GlacTracker_PSU_V1
│ ├── GlacTracker_PSU.brd - EAGLE board file
│ ├── GlacTracker_PSU.sch - EAGLE schematic file
│ ├── GlacTracker_PSU_BOM.xlsx - Overall BOM
│ ├── mgc1g18_GlacTracker_PSU.zip - Gerber Files
│ ├── mgc1g18_GlacTracker_PSU_JLC_bom.xls - BOM for JLC pick and place
│ ├── mgc1g18_GlacTracker_PSU_top_cpl.csv - CPL for JLC pick and place
├── GlacTrackerMCU_V1
│ ├── GlacTracker.brd - EAGLE board file
│ ├── GlacTracker.sch - EAGLE schematic file
│ ├── mgc1g18_GlacTrackerMCU.zip - Gerber Files
├── GlacTrackerMCU_V2
│ ├── GlacTracker.brd - EAGLE board file
│ ├── GlacTracker.sch - EAGLE schematic file
├── GlacTracker7 - an Eagle7 respin of the separate PSU and MCU boards into a single board
│ ├── tracker.brd - EAGLE board file
│ ├── tracker.sch - EAGLE schematic file
This is in IT3 (IceTracker3) and will be the second deployed system in Iceland in 2023. It has a simplified PSU: 3.3V and 4V with added FET switches to control power to various modules. The GSM and SWARM are swappable and only one can be installed (to avoid issues with UARTS and we only need one) It relies on several commercial boards: thing+, sparkfun ublox m9 GPS, sparkfun SWARM, Adafruit SD and Ardusimple's version of Xbee radio.
GlacTracker_PSU designed first to provide 3 configurable supplies through the MP2155 switching regulators. As well as a connection to the "battery" (the output of the BQ24074 Li-Ion battery Charger)
- The default settings are:
- 3.3V
- VCC_1 (set to 3.3V) with an optional 3.3V LDO which can be enabled by setting VCC_1 to around 4V (by changing resistor values) and connecting jumpers.
- 5V
- V_GSM - connection to the "battery" as described above
Each of these supplies can be enabled or disabled through both on board jumpers and via an external 6-way JST connector meaning when all supplies are disabled the leakage current is very low.
After testing it was found that using the V_GSM connector to power the GSM module was not viable as it cannot operate on voltages below 3.3V. Given this system uses Li-Ion batteries that can go as low as 2.8V, this was not a viable option.
Instead VCC_1 was set to 4V by changing R8 to 120k and two 470uF capacitors were added to the V_BAT input on the GSM module to handle current spikes during transmission. This means GSM can be used in all battery charge states.
- The current supply is setup as follows:
- 3.3V - used to power MCU, GPS and radio. Enabled via RTC alarm enable circuit
- VCC_1 - set to 4V used to power GSM. Enabled by MCU on demand
- 5V - used to power SWARM. Enabled by MCU on demand
- V_GSM - NO LONGER USED TO POWER GSM, when enabled can be used to read V_BAT
- V_GSM is now redundant as is being powered through 4V supply
- LDO is not being used to can be removed
This is the the "MCU" board with the MCU, GPS, Radio, GSM & SWARM.
The hardware is the same for a base station and rover, however the GSM & SWARM modules are not fitted on the rovers.
Contains minor changes from V1 that were discovered after V1 had been "ordered":
- Capacitors added to V_BAT pin of GSM
- Diode removed from PSU_EN as not required.