System of Wireless Battery-powered Pagers

Written by Grega Bernot on March 15, 2016

We developed a system of wireless battery-powered pagers for restaurants.

Developing products is not product development


A few years ago, we were focusing on product development. We were keen on developing new electronic products that would solve customer problems, and we were eager to manage the whole product development and production cycle, including marketing and customer support. And to be honest, it was not easy at all.


Namely, for a rather small team it is quite demanding to manage even a single product. You need to have a clear roadmap that derives from customer demands which are captured by a dedicated product manager. You need to know your customer and all the problems your solution needs to address.

We started developing a new product based on a problem many of us had when visiting restaurants: not being noticed by the waiter. As engineers, we soon realized the solution was quite simple and immediately thought of pagers. On the other hand, we did not realize that by developing a technological solution to this problem, we would have been required to do technology push instead of the far simpler market pull. We thought that we could have simply developed battery-powered wireless restaurant pagers. So we did.

Not one, but three pagers


What we developed was an ingenious paging system for restaurants consisting of three pagers - one for each role in the process of visiting a restaurant (table pager, waiter pager, and kitchen pager).

When the guest presses the blue button on the table, waiters immediately receive the number of that table on their pagers which also vibrate on every new notification. When the food is ready and waiting in the kitchen to be delivered to the table, the cook can simply enter the number of that table into the kitchen pager, and the waiter pager vibrates and displays it. Finally, when the guest wants the bill a simple press of the green button on the table does it. Of course, all waiter pagers are synchronized.


Restaurants normally don't have plastic tables, right?


If we wanted to develop a product that would nicely fit on restaurant tables, we needed to visually match it with its operating environment. Plastic pagers look cheap. That is why we decided to produce wooden pagers.

Of course, developing a custom wooden enclosure required a different approach, rather complex in comparison to just selecting an industrial plastic case. First, we had to develop some models in order to verify feasibility.

Modeling

Since we decided to develop our own wooden enclosure for the table pager, we needed to make its 3D model in order to not only provide the manufacturer with production instructions, but to also predict how the PCB will fit in. Overall, we did a nice job and managed to squeeze electronics and all the components including two AAA batteries onboard. Some components were even placed between the battery holders in order to save space. For better reception, the antenna was placed on a separate vertical PCB that was mounted on the main PCB by means of soldering.


The kitchen and waiter pagers were also modeled to make sure that all PCBs would perfectly fit in desired enclosures.

PCB design

We designed all the pagers on the same platform, namely Texas Instruments (Chipcon) CC111x system-on-chip. Its RF interface allows communication on multiple frequencies, and we decided for 868 MHz for systems used in the European Union.

Special attention has been given to the battery-powered pagers to achieve longest possible autonomy. This is why the table pager has been designed to work approx. 2 years before changing batteries. Namely, we designed the table pager's PCB to be powered off and being woken up by a key press that sends the required message and disconnects power afterwards.




When we were developing the pagers, we were in contact with our suppliers to make sure we were developing by their recommended best practices. In the end, the supplier of the vibrating motor in the waiter pager was quite enthusiastic about our solution, so they decided to post it on their blog.

Firmware for that many pagers


After developing the PCBs and equipping all the cases with specially designed foil overlays to cover the keys and LEDs, we needed to program the firmware. Every pager's firmware is a complex statemachine that simultaneously manages multiple tasks, such as RF communication, UI management (keys and LEDs), charging through USB, etc. For RF communication, our base was the SimpliciTI stack which, indeed, simplified our development process.

Final product

In the end, all these tasks and details contributed to a nice production-ready restaurant system. As such, it has of course been tested in real environments and proved to be efficient and functional.

Although today MULTILUX mostly performs custom R&D projects for known clients, this experience allowed us to gain better knowledge in understanding customer demands since we were in the role of product managers. And with this knowledge, we can now better listen to our clients.

Does your project require a full-stack engineering team?

Drop us a line and we will be more than happy to work on an exciting new project with you.

  Back to Projects