weatherbox:guava:previous_semesters

Guava Previous Semesters

Team Guava is an ongoing project, with different members every semester. In an effort to track progress made by these groups, every semester they document their achievements and obstacles. This helps future groups look back on other members advancements and goals for Guava. Our progress for every semester can be found below.

During the Spring of 2020, Team Gauva acquired two new members, Max Mochizuki and Riley Sodetani. They were familiarized on the board functionality and design using breadboards and schematics. One of the first tasks that was accomplished was boot-loading the AMTEGA1284P, with the help of former SCEL member, Kenneth. Team Guava next reviewed the REV CIV schematics to tackle the solar charging circuit design. It was determined that the capacitors on the solar charging circuit were magnitudes smaller than necessary, so the appropriate changes were made in Autodesk EAGLE.


During the Spring of 2018, Team Guava successfully designed the first iteration of a more powerful sensor module using the ATMEGA 1284 microprocessor for the lab and populated four boards confirmed to successfully and reliably boot-load and program except for one board.

Initial data shown improvements over its predecessors. It also increased computing power, local memory, and battery capacity. With this new design, SCEL’s sensor modules will be able to accommodate more sensors application software.

After populating our boards, we found some errors in our first schematic and PCB design. We found out that we're missing reset connection for bootloader, missing several data connections, and missing a reset button circuit. We added connections on our boards by using jumper wires to test program. Program successfully polls data and displays data polled, but does not transmit packet correctly. However, our board broke during the debugging process for the XBee. We tried to deploy our board on the roof but then right when we closed the lid for the housing, data from our weatherbox wouldn't transmit anymore.

Whats Next

Next semester, Team Guava will deploy a finalized design and use initial data to optimize the modules performance. We will optimize power consumption, including reset button, and update to new solar sensor. We will also build sensor breakouts on main PCB to reduce costs. Lastly, we will revise our schematic and PCB to fix some issues we've encountered this semester.


During the Spring of 2018, Team Guava successfully designed the first iteration of a more powerful sensor module using the ATMEGA 1284 microprocessor for the lab and populated four boards confirmed to successfully and reliably boot-load and program except for one board.

Initial data shown improvements over its predecessors. It also increased computing power, local memory, and battery capacity. With this new design, SCEL’s sensor modules will be able to accommodate more sensors application software.

After populating our boards, we found some errors in our first schematic and PCB design. We found out that we're missing reset connection for bootloader, missing several data connections, and missing a reset button circuit. We added connections on our boards by using jumper wires to test program. Program successfully polls data and displays data polled, but does not transmit packet correctly. However, our board broke during the debugging process for the XBee. We tried to deploy our board on the roof but then right when we closed the lid for the housing, data from our weatherbox wouldn't transmit anymore.

Whats Next

Next semester, Team Guava will deploy a finalized design and use initial data to optimize the modules performance. We will optimize power consumption, including reset button, and update to new solar sensor. We will also build sensor breakouts on main PCB to reduce costs. Lastly, we will revise our schematic and PCB to fix some issues we've encountered this semester.


During the fall of 2017, Team Guava successfully implemented the new Atmega1284 on a breadboard circuit with various sensors. This included finding the Atmega1284 pin assignments, bootloading the processor, and deciding on the sensors that will be used for the final product. The sensors are the BME280 pressure/temperature/humidity sensor, the GPS V3 breakout board, and the Apogee 215 solar irradiance sensor. The team then designed a schematic and printed circuit board for the system. A prototype housing was designed for the board.

The first step was to design a high-level road-map of how the hardware will be designed. Thus, we started by creating a block diagram describing the basic components of the weatherbox.

 Block Diagram Version 1

After the preliminary design review, we noticed that there are a few flaws to this design. We decided to not include the SHT11 in our final design, as well as implement a physical switch to change the RX/TX connections from the XBee to the programmer header.

 Block Diagram Version 2

After testing each individual sensor and bootloading the Atmega1284 processor, we then moved on to designing the system's schematic and PCB design. During the middle of this process, we added another voltage regulator to the design because we were worried that the XBee wouldn't receive enough current. Now, the XBee header has it's own dedicated voltage regulator so current draw won't be an issue.


The PCB design was made to minimize trace complexity and plane bottlenecking. The PCB design went through many iterations and revisions as the team got used to the different nuances of designing a functioning PCB. The final design is 2.8 x 3 inches.


Whats Next

The team still has to print and test the PCB, as well as write the software to run the sensor module. Housing still has to be refined into a final product. Once preliminary testing and debugging has been completed, the team will use data from the board to calculate a theoretical power budget. From there, they will decide if further improvements have to be made or if the design is ready to be deployed.


Authors

Contributing authors:

mmochizuki

Created by mmochizuki on 2020/09/28 06:32.

  • weatherbox/guava/previous_semesters.txt
  • Last modified: 2021/09/19 21:59
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