This is an old revision of the document!
Guava - Week of February 13, 2017
Attended: Tryston, Michael, Kaeo
Updates
- Fixing the Wiki
- Adding Datasheets and Presentation pages to project details
- Changing 4th generation → 5th generation
- Looking into different types of sensors to include to Guava
- Going through our previous BOM, found that the pressure sensor (BMP180) has been
- Started on PCB Schematic design
- Schematic grid size is set to 50 mil. If space is needed, we can drop down to 10 mil or 5 mil only.
- This will keep all our parts is uniform and in line when connecting
- Use same grid size rules for board layout
- DL-ed newest version of EAGLE (8.0) - to be all on the same software; to avoid unnecessary problems
Parts Ordering
- Created BOM and Parts list spreadsheet - started adding the major components
- Microprocessor - ATmega1284P
- Pressure Sensor - BMP E80
- Previous model (BMP 180) discontinued by vendor Adafruit
Issues
- Charging Circuit
- Cranberry or Dragonfruit
- Solar Panel
- Single or Double
- Barrel Jack Fittings are different
- 3.3V or 5V?
- Compatible Sensors - BME and the Pyranometer
- Decided 3.3V
- BME, Pyranometer, and ATmega are 3.3 compatible
- BME - Takes 3-5V and steps down to 3V on the chip using its own regulator
- Pyranometer - 'Should' take an input close to the output ~ 2.5V
- ATmega - Operating Voltage is 0-5V - at 3.3V the operating freq is 0-10Mhz. We can use a 8Mhz clock like Cranberry