Taylor Daniels

Mobile + Connected Device Case Study

Talli stable Android logging for a physical quick-entry device.

Talli sits at the intersection of mobile product work, connected-device reliability, and caregiver trust. Taylor worked across the React Native interface, the Expo SDK 52 migration, native Android release readiness, and the hardware upgrade from ESP-12S to ESP32 for a physical button device that sends quick care events into the app.

The final v1.3.4 release story is practical and technical: make the hardware handshake observable, keep SDK 52 state consistent, and present button events, battery, signal, provisioning, and diagnostics in a calm Material 3-inspired Android experience.

Talli Care logo

Release

Version 1.3.4 on final release branch v1.3.4-release

Platform

React Native / Expo SDK 52 targeting Android 16 Beta and API Level 36

Hardware

ESP32 upgrade from ESP-12S for a physical quick-entry button device with Wi-Fi handshaking and firmware v1.0.8 diagnostics

Problem

The project demanded mobile care, release discipline, and hardware patience.

Button entry has to feel trustworthy

A physical button press only helps caregivers if the app reflects the event consistently, clearly, and without confusing layout shifts.

The SDK migration solved visual instability

The move from Expo SDK 48 to SDK 52 was the key architecture change behind sharper Android 16 layouts and high-density display confidence.

Provisioning is an invisible workflow

Bluetooth pairing, Wi-Fi handshakes, baud-rate timing, and router behavior needed to be made observable enough to debug and explain.

Actual App Screenshots

The case study can show the real app surface directly.

These full-screen captures keep the portfolio grounded in the real product: caregiver logging, device management, pairing instructions, custom buttons, and account workflows.

Screenshot 1 of 12

Home dashboard

Care logging

The primary caregiver surface: child context, core event buttons, last-log details, and quick actions that map cleanly to the physical button device.

Talli home dashboard with child profile and care logging buttons

System View

A mobile app is only one part of the quick-entry system.

The work crossed several boundaries: caregiver-facing screens, Expo and Android tooling, ESP-12S to ESP32 migration concerns, firmware behavior, physical button event propagation, Wi-Fi state, and the release path needed to get updates into the hands of testers.

1

Button device

Captures quick caregiver events from physical button presses on the Talli device.

2

ESP32 upgrade

Moves the hardware foundation from ESP-12S to ESP32 for a more capable connected-device implementation.

3

Wi-Fi handshake

Propagates low-latency button events into the mobile app once provisioning completes.

4

SDK 52 state

Normalizes hardware events and device state into data-driven React Native UI components.

5

Material 3 UI

Displays dashboard, provisioning, and diagnostics views with Android 16 visual stability.

6

Native release

Packages Android artifacts for testing, Play Console review, and release readiness.

Implementation

Taylor helped make the system stable enough to ship.

  • Re-architected the React Native foundation around Expo SDK 52 after SDK 48 caused high-density Android layout regressions.
  • Modeled dashboard state around real quick-entry concerns: button events, battery health, Wi-Fi signal, device status, and diagnostic logs.
  • Supported the device hardware upgrade from ESP-12S to ESP32 while preserving the one-touch event-entry purpose.
  • Stabilized ESP32 flashing and provisioning by isolating baud-rate handshake timing, firmware behavior, physical button event propagation, and network assumptions.
  • Kept the Android path native-first, with APK/AAB release work aimed at Play Console submission instead of Vercel production.
  • Treated device-to-app consistency as the main dependency between ESP32 Wi-Fi handshakes, button events, and SDK 52 state management.

Release Path

Expo migration work had to end in a usable Android build.

SDK 48 to SDK 52

Move the app onto Expo SDK 52 so the Android UI could rely on newer layout behavior and sharper high-density rendering.

Android 16 target

Prepare native Android artifacts with API Level 36 compatibility, installability checks, and beta platform behavior in mind.

Play Console

Treat APK/AAB deployment as the production path, with Vercel kept only for secondary web artifacts.

Debugging Loop

ESP32 button-device troubleshooting required patient narrowing.

  1. 1Reproduce handshake failures across flashing, baud rate timing, and normal home Wi-Fi conditions.
  2. 2Separate ESP-12S assumptions, ESP32 firmware behavior, Bluetooth pairing, physical button events, router settings, and React Native state updates.
  3. 3Confirm that diagnostic metadata reflects the real device state before tuning the UI.
  4. 4Translate each resolved failure path into clearer caregiver-facing status and engineering diagnostics.

Outcomes

The case study frames Talli as practical connected-system work.

Stable release frame

Version 1.3.4 can be presented as a coherent mobile, Android, and connected-device milestone.

Event clarity

The case study shows how physical button events, hardware state, provisioning, and diagnostics become readable product surfaces.

Engineering range

The project shows Taylor moving comfortably between UI work, build tooling, deployment, and hardware-adjacent debugging.

Lessons

What this project shows about Taylor as an engineer.

Hardware state is product state

A missed or delayed button event is not just a technical defect when the user is relying on the device in a caregiving routine. The interface has to explain what the system knows.

Migrations need visible reasons

The SDK 52 migration mattered because it solved concrete Android 16 layout and density problems, not because newer tooling is automatically better.

Diagnostics belong in the story

Firmware versions, build metadata, and target platforms are portfolio-relevant when they show how deeply the mobile app and hardware layer were integrated.

The screenshot gallery uses real app captures while keeping the story focused on the engineering surface: SDK migration, Android deployment, ESP-12S to ESP32 hardware work, physical button event consistency, and the responsibility of designing around caregivers.