We began by using off the shelf components to create a functional prototype. A Raspberry Pi embedded Linux system coupled with relay boards, and RFID hardware, along with industrial power back up components. The early prototype let us address problems quickly and begin developing the control software.

After integrating hardware, it was packaged in a modified hard case to meet the weather and shock resistance requirements.

The system required two RFID antennas to determine direction of travel. With no cost effective off-the-shelf component that met the adjustability requirements, a prototype mount was quickly 3D printed.

Several antennas were tested and a set was selected. The prototype was installed on site and began recording data, uploading it to a web service via a built in cellular connection.

An additional two units were build, incorporating lessons learned from the initial implementation. Here can be seen the “guts” of the prototype along with its backup power supply system.

Our client began receiving positive feedback on the prototype so a run of several units was built to test on other sites. During this production run we reached the limits of quick manufacture and software updates.

A more compact and easier to manufacture unit was conceived to meet production needs and improve upon lessons learned during the prototyping phase. The original prototype is on the left, the new model on the right.

Instead of off-the-shelf components, which required labor intensive wiring and assembly, the next version would integrate all power supplies, communications, and control circuits on a single PCB. Here a prototype board is routed and ready for printing.

The first prototype control board is delivered and components are assembled for testing of design. There is no comparison to a real world hardware test.

A custom branded case was designed for manufacture by a case supplier, all components were designed to attach to the case with water proof connections.

After designing the case and validating the circuit design, the PCB was re-designed with improvements and in a form factor compatible with packaging.

The boards were delivered to a supplier to “pick-and-place” all the components and conduct soldering and initial testing. The boards were delivered ready for integration into the case.

The new cases were manufactured ready for assembly including branding and graphics. Components such as switches and indicator lamps were supplied with connection leads attached for quick assembly.

We pride ourselves on highly accurate CAD models of every component. This ensures packaging is successful the first time. All the components of the unit were place and manipulated ensuring a perfect fit.

Here picture is the new control board mated to its power regulator heat sink, and redundant power supply battery. The case could be completely sealed, and the unit could maintain connectivity despite power loss.

The custom control system chiefly interfaced with the RFID sub system which powered the antennas and conducted scanning. The RFID unit communicated with the control system via network, which then processed the data and relayed it over cellular to a web service.

Here version 2 is installed on a construction site scanning for personnel tagged with a specially produced RFID tag. The new system was far more fault tolerant and could be remotely controlled and receive firmware updates. 20 additional units were ordered for production.