Turnkey Product Development: Smart Shower Head Design

Project in a Nutshell:

We helped an innovative electronics supplier enter a new niche market by developing a turnkey smart shower head that saves water and energy. This device includes user distance detection, temperature control and two modes of operation. With Promwad's support, the shower head will be certified for the European and American markets, paving the way for producing the first batch. 

Client & Challenge 

Our client, a supplier of innovative electronics for various fields, is developing a new market niche: smart home devices. As part of the expansion, it plans to launch several new solutions, including a smart shower head with a rain effect, water-saving function and reduced energy consumption. He turned to Promwad for turnkey development, from design to production launch. 

Solution

The key requirements of the device are environmental friendliness, resource-saving, and safety. Promwad developed such a device, which not only increases the level of comfort and water-saving but also complies with international safety standards. To realise this project, we assembled a team comprising: 

• a hardware development specialist who was responsible for sensor integration, water flow control and energy optimisation; 

• industrial and mechanical designers; 

• PCB design engineer; 

• software and firmware engineers;

• mobile app developer; 

• testing engineer; 

• project manager. 

1. Concept Development

During the planning phase, we identified the main hardware and software components, proposing suitable materials and construction methods for the enclosure. We recommend using pre-painted plastic for parts to minimise costs, eliminating the need for post-moulding painting. 

The device connects to Wi-Fi at 2.4 GHz (IEEE 802.11 b/g/n) for stable connection to devices and networks. It also supports Bluetooth beacons for additional integration and control. 

The smart showerhead has the following features: 

• user distance detection (from 0.3 to 3 metres) and height recognition from 0.9 to 2 metres; 

• temperature measurement ranging from 15 to 46°C every 60 seconds, maintaining a stable temperature; 

• water flow regulation; 

• two operational modes: full flow and low flow, with a switch time of 10 milliseconds; 

• automatic switch to full flow mode in case of failure; 

• service life of at least 18,000 uses or five years. 

The device must comply with US FCC requirements and European CE standards. The device certification will be carried out in a third-party independent testing centre with the support of Promwad. 

2. Hardware Design

The device architecture features two microcontrollers: a main processor based on the Nordic MCU and an ESP32 wireless communication module. This combination leverages the energy efficiency of the Nordic MCU and a unified software solution that supports both platforms. The Nordic MCU has 192 KB of RAM for the main firmware, while the ESP32 includes 4 MB of flash memory for storing 3-50 shower events. 

The electronics of the device are encased in a protective waterproof layer, with all components integrated into a single PCB, simplifying design and enhancing reliability. Monitoring sensors for temperature, distance, and flow are concealed within the housing, eliminating the need for an on/off button. 

Powered by four AA batteries, the showerhead minimises power consumption through a sleep mode, activated when no object is detected for a predetermined period. 
 

3. Software Development

Promwad engineers developed software to control the device, which performs the following functions: 

• Control of sensors and water flow. 

• Determining the shower status (on or off). 

• Monitoring and data storage: the device measures the battery charge level and stores the shower parameters in NVRAM. It also calculates the water-saving ratio based on the shower parameters. 

• Data sharing and debugging: all shower cycle data is sent to AWS. Beacon and LED/logs are used for debugging. 

4. Enclosure and Mechanical Design

Business Value 

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More of What We Do for Smart Home

• Mobile App Development: explore our custom mobile app development services for smart home systems. 

• Intercom Panel Design: a case study on developing an intercom panel for smart homes with contactless card authorisation. 

• Designing Energy-Harvesting Gadgets: our study of a new technology and its possible applications.