LIFT BIT: the connected sofa

By on August 18, 2017
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Design and technology in a perfect marriage: applying the DUST network for internet enabled control of an innovative modular sofa that can be adjusted at will, thanks to an electronic section prototyped with SmartEverything.

 

In the previous issues of Elettronica In we have introduced the new SmartEverything family, a wide range of application prototyping boards for the Internet of Things which board/cards are equipped, depending on the model, with various low-power wireless links, besides possible LE Bluetooth and Wi-Fi and GPS. To be specific, in the last post we took a look at the DUST protocol in the version proposed by Linear Technology, implemented on the SmartEverything DragonFly board through the integration of the IOTEAM’s Dusty module, partner of Arrow Electronics in the creation of the SmartEverything project.

We have already praised the DUST protocol, highlighting its main values, especially for the realization of mesh type WPAN networks, and now it’s time to see a practical example of what we can do with it, to also show its real-life implications. We do that by analyzing a case study proposed by IOTEAM: last October at Electronica 2016 (a professional trade show in Munich) they introduced the general public to an application fit for real, everyday life, involving a meshed wireless network that uses the SmartMesh IP technology by Linear Technology, for digitally controlling the first “digitally adjustable” sofa, the Lift-Bit, by the renowned design and innovation studio Carlo Ratti Associati. Thus, the Internet of Things has finally found its place even in the field of interior design thanks to an initiative by the studio that invented the first connected furniture system.

This case study is interesting not only because it makes use of the same Dust network implemented in the SmartEverything DragonFly, but also because the electronics section has been prototyped on this very board before the creation of the Network Manager and Mote units, which have been created as we will describe shortly.

SmartMesh is the only Dust network created to meet IoT’s stringent requirements of reliability and safety for the industrial sector.

Here is a recap of its features:

  • >99.999% network reliability; SmartMesh provides the business-critical data where other solutions fail (please note that industrial applications do not tolerate error percentages over 1%, which means losing 3.65 days of activity per year).
  • Safety and encryption with NIST certification: data are protected end-to-end by AES 128-bit encryption, by the integrity check of messages (to prevent messages from being altered) and by authentication (the transmitter must identify itself).
  • Scalability up to 10,000 nodes allowed by time-synchronized, channel hopping technology, eliminating data collisions. Data optimization algorithms smartly balance data traffic for an effective re-routing.
  • Bidirectional communication for monitoring and controlling application: sensor data acquisition, log file research, sensor configuration, actuator control (alarms, locks, vaults, HVAC regulators etc.).
  • Blink mode, allowing support of roaming nodes, safe and reliable communication with an average absorption of 3 µA.

In the previous post issue we have described Dust technology in detail and we refer you to that issue for the technical details; here, we only remind you that SmartMesh IP is a Mesh-type wireless network, and this architecture allows to reach good coverage by relying on intermediate nodes for communication that can physically extend its range. The protocol is based on 6LoWPAN (IPv6 over Low power Wireless Personal Area Networks), which offers a reliability similar to cable solutions and very low energy consumption, allowing to safely implement IoT battery-powered sensors in difficult environments.







 

 

SmartMesh IP wireless network is time-synchronized and inside it, each node can route, generate or receive (terminate) data, providing at the same time an autonomous duration of several years when battery-operated.

The network’s nodes are called Motes and they receive and transmit data.

Motes are wireless nodes of the SmartMesh IP network; they connect sensors and actuators and route related data towards the other Motes, all with very low consumption. The name Mote is in perfect harmony with the name Dust, so if network is the dust, the nodes composing it are the motes.

Each Mote can both send and receive messages (supports bidirectional data) and can have a different data reporting rate and the network manager will automatically coordinate individual communications in pairs to route the traffic in the most efficient way possible.

Motes are managed by a SoC based on an ARM Cortex-M3 processor that, if needed, can support the client application software programmable through the IP SmartMesh On-Chip Software Developer Kit.

Alternatively, a Mote can be controlled through an external host microprocessor through its API serial interface. In our case, it functions independently and the software decides the functioning mode, which is peripheral Mote (pouf) or access point.

 

What is Lift-Bit

The sofa, designed and developed with the support of Vitra for “Stanze. Altre filosofie dell’abitare”, an exposition organized by Salone del Mobile di Milano within the XXI Triennale (Milan, April 2 – September 12 2016), is composed of a series of single hexagonal stools which are, in terms of interior designs, poufs; these are adjoining by one or more sides of the hexagons. The structure can be composed as you desire.

 

 

Each of those stools is equipped with a base and an electric linear motor that allows each element to be lifted or lowered (in respect to its base), by remotely controlling it through a tablet app, and allowing each stool to double or halve its height in a few seconds, therefore reconfiguring the shape and the space of the sofa in a multitude of combinations. The responsive modules of Lift-Bit can smoothly transform into a sofa, a bed, a tidy living room, a small auditorium, or a home landscape, depending on the needs and the wishes of the user.

IOTEAM made all of this possible with their IoT solution based on the SmartMesh IP LTC5800-IPM chip, integrated in Dusty and Dustino modules that we have analyzed in previous post issue.

The wireless control logics allows to pilot the sofa through a Wi-Fi connection, making it possible to reconfigure the space in a virtually infinite number of combinations.

Lift-Bit is as more interesting as its elements are more numerous.

Two poufs side-by-side make a seat, four elements make a chaise longue, nine elements make a big sofa: the aesthetic potential can be realized in full with a high number of hexagonal modules that allows to create the desired shape.

Art and design combines in a constant evolution enabled by the wireless technology contained in the poufs.







 

 

Technical description

The solution is composed, as we already mentioned, by a series of upholstered hexagonal poufs, that are placed side-by-side and permanently connected choosing number and configuration, with 24 V CC power.

Inside each pouf there is a linear actuator that allows vertical movement of the padded seat with the possibility to double or halve the height in a few seconds.

A bespoke electronic board includes all the necessary components to control the motor’s movements, detect limits and axis position, exchange information with the other modules.

This board is in fact characterized by a chip implementing Dust technology to wirelessly communicate with the other poufs.

The configuration provides a Master and an arbitrary number of Slaves. The Master controls movement of all the Slaves by communicating thanks to Dust technology. In turn, the Master communicates over Wi-Fi with the user application to send the position of each pouf and receive the configuration commands .  

 

 

The application includes preset interior design configurations and offers the possibility to design new combinations. The innovative wireless technology implemented into the sofa makes construction, installation and control of the sofa itself much easier: it eliminates the need for many electric cables, which are otherwise requested in each single element of the composition, by reducing the necessity to a single power cable, which is by the way a low voltage cable (24 V) to avoid risks related to proximity to electricity.

Mechanical parts and the app are by Opendot (www.opendotlab.it), while the control electronics board is from IOTEAM; a valid example of collaboration between Italian companies with specific competences and great skill in their integration.

 

The electronic board

The electronic board has been designed ad hoc but with a DIN-rail format in order to be inserted in a dedicated DIN bar plastic container that allows a simple insulation inside each pouf; on each pouf is integrated an Infineon motor controller, operating with the same 24 V powering the subsystem.

 

 

The board has two versions: Master (connected over Wi-Fi) and Slave. The Master version provides two wireless communication modes: one is on the Dust protocol network and is managed by the LTC5800-IPM SmartMesh IP chip, which allows communication with the other slave poufs composing the sofa; instead, through the Wi-Fi module you can establish a network connection to manage the system through the app. The complete unit board (master) is illustrated in figure, where you can see the little Wi-Fi module with built-in antenna (the blue one).

 

 

Linear Technology makes the SmartMesh IP 802.15.4 hardware available on a chip or through two RF-certified modules on a printed board that incorporate it.

The accompanying software (Mote software, network manager software or access point Mote software) allows to operate the hardware according to the mode requested by the final application. In the Lift-Bit project, the Master has the access point software and the slave has the Mote software.

On the other hand, the Mote version has just one wireless communication mode, the Dust network one; Mote version is associated with the controller of the linear actuator, based on a H-bridge by Infineon; the relative board lacks Wi-Fi connectivity.

IOTEAM Dust module, placed on the opposite side from the one visible in figure, is applied on both.

 

 

As we already mentioned, the electronics part has been prototyped using SmartEverything and with the Infineon development kit for the H-bridge controller which has then been integrated in the Mote board in the final version. The LTC5800-IPM Systems-on-Chip in a 72-pin QFN case of only 10 x 10 mm includes all the functionalities needed, i.e. the processor working at 2.4 GHz base frequency, protocol managing stages and all the necessary for the user application. The behavior of the LTC5800-IPM in a SmartMesh IP is determined by the choice of the software loaded: Wireless Mote, EManager or Access Point Mote. The SmartMesh IP software provided by Linear Technology with the LTC5800-IPM can be tested and simulated for all the operational modes and can be loaded through an Application Programming software interface.

 

 







About Marco Sangalli