uva-dsi / sensenet Goto Github PK

When the SCD is connected and taking readings, it increases idle power draw by about 4.3mA. When it is immediately disabled via sending 0x0104 on the I2C bus in setup() this is not an issue. However, when it is disabled and then re-enabled and read from and then disabled again, the current draw never goes back down. Could solve with a MOSFET or BJT if space allows.

Pending the final review of the schematics:

• SAML21 pinout
• KiCad footprints
• Include data sheets / partnumbers
• 3D models for kicad

To make sure that the kit is accessible to people just learning to do SMD soldering, we can ensure that we use large parts where possible, and also expand the size of the pads.

The Feather M0 LoRa draws about 0.37mA of current when idling using the sleepydog library. It would be ideal if we could push this down much further to the 0.01 or even 0.001 mA range and we should begin to explore other methods for doing this or other boards entirely that will be able to go lower than the m0 can possibly go.

Test both analog and digital I/O

Put boards together, note any difficulties that occur.

While having a circular PCB is very cool, it also means that there is a lot of wastage wherever there are no components. This may be remedied by choosing a more space-efficient board shape and size.

However, the board should still be easy to solder on, which means that it cannot be too small or dense.

Work on board layout has started, routing is pending for the Big Dot board.
This task depends on the issue #17

Make sure that the GPIO and other pins will fit onto a standard breadboard.

Add silkscreen to board for

• Pins
• Component values
• etc.

Most sensors will connect using these protocols, so they must be tested functional.

The Feather M0 LoRa draws about 0.37mA of current in idle. When the PMS is connected and the RESET held high, it runs at 1.7mA. If we could instead disconnect power from the PMS entirely using a MOSFET or BJT, we might be able to save that little bit of power and significantly increase the battery life of the device.

Right now, the LoRa radio reaches 130mA of current when sending packets. It is possible to change the parameters on the radio in a way that might reduce this current draw, especially in the circumstance that the user is very close to their gateway.

To make testing easier, can write an Arduino program that helps the user test each sensor, I/O, etc.