This week I continued working on the schematic and redesigning parts of our PCB. We had a meeting with Tamal on Friday to discuss our current schematic, and Olivia and I met today to make changes accordingly discuss what parts we need to return and now buy based on our conversation with him. I initially had most of the pieces on the schematic as components to solder on, but looking at the pieces and datasheets these pieces were already on a daughter board board, so all we need to include on the actual PCB are header pins that we can mechanically place the boards into. We also upon discussion got a new digital microphone as opposed to the analog one we previously had. In addition I added decoupling capacitors to all the components on the board and modified the schematic to correctly use the voltage regulators. I replaced the voltage regulator I had for the motor from linear to switching as to not waste power. I also added header pins to connect our external 11V battery. We are stepping it down to 5V using another linear regulator and connecting that to the battery pin of our miniESP. We also are planning to return our cell module and antenna and we are ordering a new cellular dev kit instead. this already comes with a built in PCB so we discussing how we want to deal with this. (glue it onto our existing PCB and then connect physical wires from the header pins of our PCB to the cell PCB to power and transmit information? )We need to figure that out. We also are unsure of how to connect the recharge pin of our battery. I hope to have this schematic done by tomorrow so we can send it again for feedback. I have attached the “unfinished” changes below:
Carnegie Mellon ECE Capstone, Spring 2024, Olivia C, Bradley M, Anika P