Wireless pointer

Project

Our task was to create a wireless pointing device to be used to interact with the client’s custom PC application software. The concept had been earlier proven using a pointer with its sensors connected by a flexible cable to a multi-channel ADC (analog-to-digital converter) plugged into a PC’s USB port.

The new device needed to be battery powered and operable within screen-reading distance of the PC hosting the custom application.

Innovation

The pointer uses a very small but highly-specified embedded processor with 2.4 GHz transceiver to measure the output voltages of a miniature 3-axis accelerometer and yaw sensor.

At the PC end, a matching embedded processor with radio transceiver feeds the data to the client’s application program.

Our contribution

We designed the circuit for the pointer, the layout of the printed circuit board, sourced all components and arranged contract assembly. We did not need to design the matching receiver, but instead used a generic “dongle” from the semiconductor manufacturer.

We also created the firmware for both transmitter and receiver microprocessors.

Wireless technology is becoming increasingly popular for data transmission instead of using cables between devices and computers. There are at least two reasons for this trend.

Firstly, certain frequency bands in the radio spectrum have been internationally defined for license-free operation of low power transmitting devices.

Secondly, semiconductor manufacturers are releasing new multi-function integrated circuits which combine radio transceivers with microprocessors and other functional components such as multi-channel analog-to-digital converters and USB communication controllers. They also provide function libraries that permit software developers to create robust programs which go inside these embedded processors and link them to the outside world.

The wireless pointer is a long thin printed circuit board with almost all components mounted on one side. Every electronic component has been chosen for small size. The radio aerial is at the left. The connections to the battery (not shown) are at the right.

The receiver is a tiny printed circuit board that fits inside the end of a computer USB plug. The radio aerial is on the right.

Our team’s effort

Software, 55%
Electronics, 40%
Mechanical, 5%

Client

Spark Dental Technology