handheld mobile device designPortable handheld electronic devices such as computer tablets and smartphones continue to offer amazing features incorporated from mass-produced electronic technology. Sometimes, these commercial off the shelf (COTS) devices do not quite meet user needs. Perhaps they do not withstand tough environmental conditions, require a custom interface, or don’t meet regulatory requirements driven by specific application use cases. A custom designed handheld device may be necessary for these situations. There are major challenges faced when planning a custom handheld device design.

Portable handheld computing devices have a myriad of uses across many industries. Examples include medicine, military, security, law enforcement, field operations, instrumentation and measurement, entertainment, inventory management, warehousing, logistics, shipping, transportation, and retail. These applications demand feature-rich handheld electronic devices, preferably with the familiar user interfaces of analogous consumer devices, but also meet stringent use case requirements as well as budget constraints. It is a challenge to design and produce cost-effective custom handheld devices that meet operational needs.

Planning starts with a definition of use cases – how the portable device will be used (and easily so). Requirements for sensors, wired and wireless interfaces, graphics capability, display, physical size and weight, battery life, and more must be considered.

With respect to size, sleek and lightweight portability are always desired. However, the device must be durable in the event of drops, bumps, jarring, and vibration. Reliable operation in hot, cold, damp, wet, or dusty environments is often required. There often is a tradeoff in the package design of the device, sacrificing some sleekness and a bit of weight to add mechanical features that made the device rugged and manage heat generated by internal electronic components.

Battery run time is a major consideration in handheld device design. Batteries of higher capacity, and therefore longer run time, are larger, weigh more, and cost more than lower capacity batteries. Ultimately there is a sweet spot battery capacity than enables adequate run time while keeping device size and weight (and therefore ergonomics) reasonable.

All electronic devices must meet regulatory requirements. Minimally, they must pass EMI/EMC testing in the jurisdictions of sale – FCC in the Unites States, IC in Canada, and CE in Europe, for example. However, various industries may have additional requirements, such as MIL-STD-461 and MIL-STD-810 for US military devices, ATEX for use in explosive atmospheres, ARINC for aeronautical equipment, PCI and EMV for point of sale devices, and more. Each set of regulatory requirements must be considered in the design, implementation, and test of a custom handheld or portable device.

A custom handheld or portable device must meet a target time frame for availability, which impacts part selection and cost. Many mass-volume products are available for no more than two years, often because it is expected that technologic advances will push newer and more capable components into the marketplace. However, such early obsolescence cannot be tolerated for specialized electronic devices that require relatively long development and regulatory certification timeframes. Therefore, these custom electronic devices must be made from components that are available long term. Understanding of the component supply chain and appropriate component must be planned upfront during product conceptualization and early design.

Development cost is also paramount. The resulting custom portable or handheld device must be affordable to manufacture and for its customers to purchase. Development costs, including regulatory certification testing, must also fit engineering budget constraints.

When the above factors are considered, the design of a custom portable device is a complex undertaking. A company experienced with the tradeoffs between features, environments, battery run time, and product life helps optimize the cost of both development and units in an ongoing basis.

Handheld device design is an area of excellence at InHand Electronics, an industry leader that specializes in the design of low-power embedded circuitry, systems, and software for original equipment manufacturers of handheld, Internet of Things (IoT), and wireless devices. Contact InHand for an evaluation of your custom handheld device concept.