This week, I was mainly working on finalizing components and creating the schematic for the PCB, along with working on the design review presentation.
We decided on the ESP32-P4 microcontroller for our main architecture. Originally, we were planning to use the eval board (ESP32-P4-WIFI6) mounted on our PCB, but were unable to due to there not being enough GPIO pins. As a result, the schematic has most of the main components (outside of input capacitors, pull-up resistors, etc.) but currently does not have the circuitry for anything that was handled on the eval board itself (such as power management, USB connection, and flash memory, and the clock) as the schematic symbol was changed recently. I am planning to copy these from the recommended hardware documentation as well as the eval board schematic. I also preordered 2 of these microcontrollers on the PCB assembly site I plan to use so that they are available for when I order my PCB.
For the LiPo battery, I decided on an MCP73832 for USB charging, along with a MAX17048 for gauging the battery level. These choices were based on Adafruit’s dedicated boards for these tasks; however, to save costs and space, I decided to put the ICs on my board directly. I also decided on a NCV8187 3.3V LDO regulator to supply power to the rest of the board, since the difference between the voltage of the LiPo battery is relatively small for most of the time, making the efficiency comparable to a buck converter.
I also selected connectors for the screen and battery, as well as a passive buzzer. I am slightly behind schedule, since I have not fully finished my schematic; however, I have selected all key components, so most of the work lies in creating the remaining components in my design software and double checking datasheets. This should not be a large issue, as the week I have allocated to ordering the PCB also doubles as buffer time. Next week, I need to work on layout, as well as the design report.