1.4 KiB
esp32-test
Engineer Responsible for this Section: Tarik Fawal, Willow Herron
Section README Authored By: Katherine Sarna
Datasheet:
- ESP32-C3 Series Module
Purpose of esp32-test: This is for the daughterboard that is controlled by the main (control) board. We intend to have 3 of these or more stationed at different points inside the greenhouse, for dispensing water to plants in just the right amount to have a water-saving/efficient garden.
The biggest design consideration on this board was the antenna (wireless signal). We designed our own antenna based on the reference design for the ESP32 module (not SoC). Then, that design is routed that back to ESP32 with an impedance-controlled trace, controlled by the RF attenuator pi network-- Which is basically an inductor with 2 capacitors in parallel going to ground on either side. This was then used to have more accurate matching than we could with a single impedance-controlled trace.
For design consideration in this section regarding impedance control: We used a thinner board to help impedance (Z) control, which was 0.6mm instead of 1.6mm thick. We had to break out everything needed for our sensors; an I2C pin, as well as a GPIO pin for the water pump. We also needed a USB port to program the ESP32, and here we didn't expend quite so much engineering labor on routing considerations because we did not need this to be a very high-speed signal.