This week, we worked on the proposal presentation slides on Sunday and helped Tucker prepare to present in front of other capstone students and faculty. I also began researching some of our hardware choices, narrowing down some of the systems and components we will used based on size, price, and compatibility.
We will be using an SX1262-based 915Hz LoRa module, likely a Wio-SX1262, for low power consumption and strong transmission, as well as to allow for Meshtastic compatibility. This will utilize SPI, and will require an external antenna, which may need to stick out of the housing.
For GPS modules, I narrowed it down to three options: the Quectel LC76G (PA), LG77L, or L96. The first two do not have built-in antennas, while the last one has an integrated antenna. All three are built for low power consumption as well, and will utilize I2C or UART.
We have not yet decided between STM32 or ESP32 for our microcontroller architecture, but plan to decide by the end of Monday’s class so that we can order an eval board for it in the purchasing sheet. I am still on schedule as I intentionally left my tasks light this week to allow for major obligations outside of class, but I will have to put in a lot more work next week in order to finalize components and create a first version of the schematic for the PCB. Other decisions I will have to make are the touchscreen model (160×160 + color for PalmOS apps), the number and size of buttons, and passive buzzer selection.