The Dream Timer
We were hired by a woman making a suite of electronic devices to help new mothers better manage their babies. She wanted a device that would be both a clock at night and a timer during the day, so that a mother could keep track of when her baby was sleeping. In the day she could time naps, and at night she could see the time. Our task was to make the product from scratch.
The most crucial first step of building a complete product is listening to the client diligently, and recording all system requirements. Too often contractors fulfill the requirements to find out that the client wanted something else which was never explained. We want to avoid that scenario at all costs, so we and the client rigorously defined the system's behavior from the beginning and reevaluated things once a prototype was done.
The prototype was a breadboard built with an ESP32 as microcontroller, connected to a series of LEDs and switches. We built it, programmed it, tested it, and had it in the client's hands within three days. With a proof of concept done, we moved on to designing the PCB and the plastic housing. We also switched to cheaper and smaller components, like swapping the ESP32 microcontroller for the easier CH32V003 RISC-V controller from WCH, and replacing the ESP32's wifi card with an ESP8684-WROOM-02C (also made by Espressif).
Once our client was happy with the prototype, we had a sample made in the factory, and tested it once again: this time the PCB, all the ancillary components, and the enclosure for quality control. It took some arguing with the factory and suppliers, but we got our production model within tolerance on the enclosure and behaving properly in the electronics within a month.
The client was happy, and our product became one in a line of small household devices that help make life easier for young mothers.