Review statistics and research related to Alzheimer's care and previous devices used by Alzheimer's patients. Plan the initial design of the device, including the features it will have and the materials and components needed.

Based on the design plan, select the necessary components such as microcontroller, battery, sensors, and wireless modules.

Estimate the cost of the components to ensure the project stays within budget.

Begin building the prototype by assembling the selected components according to the design plan. 

• Connect the microcontroller to the sensors and wireless modules.
• Add a battery to power the device.
• Add an LED display or other output device to display the location or other data.

Once the prototype is assembled, test it to ensure it's working correctly.

• Check that the device can locate the Alzheimer's patient if they go out unaccompanied.
• Ensure the chatbot feature sends reminders for medication and other important information.
• Test the water-resistant feature.

Based on the test results, analyze the data and optimize the prototype to improve performance.

• Replace the battery with solar panels to make the device more sustainable.
• Add a SIM module to send messages to a companion in emergency situations.
• Optimize the range of the device using a NODE MCU Esp.32 to increase the range of the device.