This week was busy because we had confirmation that we would not be able to get the PCB in time to make everything work together. Therefore, we started transitioning to a fully Arduino style project. Unfortunately this means that a lot of the physical planning and software we wrote for the PCB is going to have to be scrapped and written anew for the Arduino. I was able to connect a separate nRF24 transceiver to the Arduino and broadcast a signal that we are going to use to communicate the weight that the load cell is reading. I have attached a picture of the device down below. Unfortunately nRF24s do not have capability to connect to BTLE devices, so the only information that can be communicated is one 32bit “advertisement packet”. Luckily since we are only transmitting one value this should not be a problem. I also improved on the mounting of the scale and was able to make it accurate! I have attached a video incorporating the entire subsystem as we have it right now. Unfortunately, the LCD display broke right as I was fiddling with the SPI bus and wouldn’t display anything even after a hard reset. I have attached a photo of the broken display below. It will be challenging to make everything work compactly by the demo, but hopefully we will find some luck along the way. 
Team Status Report 3/27
This week the team made progress in researching a new load cell and using it with our amplifier. We also made progress with the firmware and ordered all the parts that won’t be assembled on the PCBs when they arrive.
Harper Status Report 3/27
Due to concerns from the design report about the load cell, I ordered a development board for our load cell amplifier and an espresso scale that measures 500g with a resolution of .01g to remove the load cell and test if we can use it for our purposes. I disassembled the scale and found that the load cell inside uses the same Wheatstone bridge connection we use for the load cell amplifier so it should work electrically. Next weeks goal is testing if it will work with our amplifier and an Arduino. If so, the CAD will be modified to use this load cell with our PCB once it comes in. The disassembly process is documented below.
Archana’s Status Report for 3/20
This week I talked about the feedback from the design review presentation with the team. We discussed the timeline and any possible changes to the work we had planned. I found some bugs with the package dependencies with Firebase and I spent some time working out the most stable way to fix the issues with download from storage. I added the bluetooth package with better app compatibility and have been trying to integrate it to the dashboard. I have been working on the “start measuring” portion of the app and creating a screen for eventual streaming capability.
Team Status Report for 3/20
This week the team focused on the design review report making sure to incorporate any details that would clarify the questions asked after our presentation. Next week we hope to make headway on the firmware and will continue to push forward on the firebase/app development.
Harper’s Report for 3/20
This week’s focus was mainly the design report and finalizing design documents so that they could be included in that. This includes finalizing the power consumption analysis and double checking how everything connects within itself. Since I didn’t get to start looking into firmware this week like planned, that will be a priority next week.
Harper’s Report for 3/13
This week I focused on the verification documents for the PCB and the power consumption analysis for the system. The power consumption analysis was completed to the point where the verification documents needed. Further work on the verification documents will be done after some preliminary firmware is written so that we can test bring up software. Next week will be dedicated to firmware and getting estimates on battery life given the power consumption analysis.
Team Status Report for 3/13
This week the team did the design presentation. We put the PCB Cad into the shell design as well as go through the integration of the components into the shell. We set up upload and download with cloud storage and made progress on the dashboard of the app. This week we have to work on finishing up the physical design report.
Archana’s Status Report for 3/13
This week I continued work on the app. I was able to get upload and download both working for Firebase. I started work on the dashboard and now the posts can be uploaded to the database and then show up on the dashboard. Also working on the button and page functionality for measuring. I added the bluetooth package and read through documentation more. Will work on that this week.
Status 3/13
This week the team did the design presentation. I was able to put the PCB Cad into the shell design as well as go through the integration of the components into the shell. I still have to add in the correct buttons to the face of the scale. This week we have to work on finish up the physical design report as well as going through the feedback from the presentation. I am going to start working on the base firmware for the scale which will take some time, but hopefully will not be a bottleneck.