VAAYU · TPMS system-on-chip

The tyre sensor,
on a single chip

VAAYU combines pressure and temperature sensing, a RISC-V controller and a 433.92 MHz transmitter on one die. It is designed in India for Indian roads, climate and standards.

In developmentAIS-154UN ECE R141RISC-V
Request evaluation →See use cases

Low power

Designed around sleep current, so a coin cell lasts for years.

Small footprint

One die instead of three chips, for a compact valve-mounted module.

RISC-V controller

An open-architecture digital controller runs the detection logic.

In-house design

Digital, analog and RF are all developed by our own team.

How it works

Four steps from tyre to dashboard

  1. 01

    Sense

    Pressure and temperature inside the tyre are measured on the chip.

  2. 02

    Decide

    The RISC-V controller checks readings against detection rules aligned with AIS-154.

  3. 03

    Transmit

    A 433.92 MHz transmitter sends a short data frame to the receiver in the vehicle.

  4. 04

    Alert

    The receiver passes the alert over CAN and the dashboard telltale lights up.

Use cases

Three vehicle segments, ICE and EV

Tyre pressure matters on every vehicle, for different reasons. VAAYU is one chip designed to cover all of them.

01 · Trucks · buses · trailers

Commercial vehicles

VAAYU sensor Receiver

Eighteen tyres, one receiver, zero guesswork

A loaded truck runs on many axles and dual tyres at high pressure for hours at a stretch. An underinflated inner tyre is almost impossible to spot on a walk-around, and it is usually the one that fails.

  • Pressure range to 10 bar, sized for truck and bus tyres
  • Many sensors per vehicle reporting to a single in-cabin receiver
  • Long battery life, so the sensor outlasts the tyre
ICE
ICE fleets

Correct pressure cuts rolling resistance, so less diesel is burned per kilometre, and it protects the tyre casing for retreading.

EV
Electric buses and trucks

Battery packs add axle load and every bit of rolling resistance comes out of range. Tyre data becomes part of energy management.

02 · Cars · SUVs · light commercial

Passenger vehicles

VAAYU sensor Receiver

Built for the AIS-154 mandate

AIS-154 brings tyre-pressure monitoring to M1 and N1 vehicles in India. Carmakers need a compact valve-mounted sensor that meets the detection timings and is available from a domestic supply chain.

  • Puncture warning within 10 minutes, diffusion warning within 60
  • Small, light module that sits on the valve stem
  • Low bill of materials for cost-sensitive platforms
ICE
ICE cars

A dashboard telltale gives drivers time to act on a slow leak, and correctly inflated tyres return better fuel economy.

EV
Electric cars

EVs are heavier and deliver instant torque, which is harder on tyres. Pressure has a direct effect on the range a driver sees.

03 · Motorcycles · scooters

Two-wheelers

VAAYU sensor Receiver

Two contact patches, no margin

On two wheels, a tyre that loses pressure affects balance and braking straight away. India rides on two-wheelers, yet tyre pressure is still checked by eye or not at all.

  • The smallest and lightest sensor possible on a small rim
  • A single chip keeps module size and cost down
  • Simple warning on the instrument cluster
ICE
ICE motorcycles and scooters

Daily commuters and delivery riders get an early warning before a soft tyre becomes a fall, and tyres last longer.

EV
Electric scooters and motorcycles

Range matters on every charge. Digital instrument clusters on electric two-wheelers make tyre data easy to show to the rider.

Use case in actionApplication demo

CaneSense: fair weight for every load, from farm to factory

A sugarcane farmer is paid on one number, measured on the factory weighbridge where he cannot see it. CaneSense puts a VAAYU sensor in every tyre of the tractor and trailer, so the load is weighed from the moment loading ends.

1 min 40 s, with on-screen captions. CaneSense is powered by the VAAYU TPMS SoC.

Every tyre becomes a load sensor

Tyre pressures are baselined on the empty trailer and corrected for temperature, so heat is not mistaken for load.

One shared record

When loading ends the payload is sealed and sent to the farmer, by app or SMS, and to the factory desk at the same moment.

Agreement, not argument

At the weighbridge the two numbers are compared, and a re-weigh is called only when they disagree.

Architecture

What is on the die

Every block between the air in the tyre and the antenna is on one piece of silicon.

VAAYU SoC · SINGLE DIEINSIDE TYREAir pressureTemperaturePressuresensingTemperaturesensingAnalogfront endsignalconditioningRISC-Vdigital controllerdetection logicframe buildingRF TX433.92 MHzASK / OOKPower managementsleep / wake timing · 2.1–3.6 V coin cellLF RX125 kHz wake-upwake-up125 kHzIN VEHICLEDashboardwarning telltaleCANReceiverin-cabin ECULF triggerinitiator / tool

Pressure and temperature sensing

Measures the air in the tyre. Temperature is used both as a safety signal and to interpret pressure correctly.

Analog front end

Amplifies and conditions the small sensor signals and hands clean values to the digital logic.

RISC-V digital controller

Runs puncture, diffusion and malfunction detection, and builds the frames that go on air.

RF transmitter

Sends frames at 433.92 MHz in the ISM band using ASK/OOK modulation.

LF wake-up receiver

Listens for a 125 kHz low-frequency trigger and wakes the controller on demand, for example during sensor pairing or service.

Power management

Keeps the chip asleep most of the time and wakes each block only when needed, from a 2.1–3.6 V coin cell.

Specifications

Target specifications

VAAYU TPMS SoC target specifications
ParameterTarget value
Pressure sensing range0–10 bar (145 PSI)
Temperature range−40 °C to +125 °C
RF frequency433.92 MHz (ISM band)
ModulationASK / OOK
Digital controllerRISC-V
Supply voltage2.1–3.6 V (coin cell)
Target battery life5–10 years
Vehicle interfaceCAN bus (via receiver ECU)
Target vehiclesTwo-wheelers, passenger, commercial

These are design targets. Final values are subject to silicon validation.

Why a SoC

One chip against a board full of parts

VAAYU SoC

  • Sensing, controller and RF on a single die
  • Smaller board, valve-stem mounted module
  • Lower power draw, 5–10 year battery target
  • Fewer parts to buy and assemble
  • Designed in India
  • Designed for AIS-154 type approval

Discrete TPMS module

  • Separate pressure IC, microcontroller and RF IC
  • Larger board and heavier module
  • Higher power draw, shorter battery life
  • More parts and a longer supply chain
  • Imported chips
  • Compliance work repeated per market

Standards

Designed to the rulebook from day one

VAAYU targets India's AIS-154 and the international UN ECE R141.

AIS-154India
  • Administered by ARAI, mandated by MoRTH
  • Vehicle categories M1 and N1
  • Operating temperature 0–50 °C for Indian conditions
  • Puncture warning under 10 minutes, diffusion under 60
UN ECE R141International
  • Extends to buses (M2, M3), heavy trucks (N2, N3) and trailers (O3, O4)
  • Scope is expanding across heavy commercial vehicles
  • Opens an export route for OEM customers

AIS-154 compliance targets

§5.2

Puncture detection

Warn within 10 minutes of a rapid pressure loss of 20% or more.

§5.3

Diffusion detection

Warn within 60 minutes of slow pressure loss, on up to four tyres at once.

§5.4

Malfunction detection

Alert the driver within 10 minutes of a sensor or system fault.

§5.5

Warning indication

Yellow dashboard telltale: steady for pressure loss, flashing for a system fault.

Development status

Where VAAYU stands

  1. Done

    Architecture and FPGA prototype

    SoC architecture defined and the digital design prototyped on an FPGA.

  2. Now

    SoC design and verification

    Digital, analog and RF design, simulation and verification are under way.

  3. Next

    Tape-out and engineering samples

    First silicon, followed by sample modules for evaluation partners.

  4. Then

    Validation and OEM pilots

    Silicon validation, AIS-154 type-approval testing and vehicle integration pilots.

Building a vehicle or a TPMS module?

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