PARAKH

परख · A CROP-HEALTH FIELD ROVER

Parakh

A small rover with a sharp eye,
built for Indian farms.

Parakh is a 3D-printed, rocker-bogie field rover that drives crop rows, watches leaves with an onboard camera, and probes the soil beneath them — so disease and soil trouble get caught early, not after a harvest is lost.

Explore the rover How it works

6-WHEEL ROCKER-BOGIE · ESP32 + ARDUINO · CAMERA + SOIL SENSING · ≈$120 IN PARTS

The Parakh rover prototype on a workbench: black 3D-printed chassis wrapped in gold mylar foil, orange rocker-bogie arms, yellow wheels, and a mast carrying twin ultrasonic sensors.
THE CURRENT BUILD — GOLD MYLAR WRAP, TWIN ULTRASONIC EYES
SCROLL

खेत · THE FIELD

By the time a field shows it,
it’s often already late.

On a smallholding, crop disease is found the way it has always been found — by walking the rows and looking. It works, but it doesn’t scale, and the earliest signs are the easiest to miss. Parakh is a different pair of eyes: a small, cheap, tireless rover that patrols between rows, photographs leaves, and flags what looks wrong — while its probe checks the soil those crops are standing in.

  • LEAVES early visual signs of crop disease, caught by camera
  • मिट्टी · SOIL moisture today — pH and anomaly detection next
  • MICROCLIMATE temperature, humidity, pressure and air quality between the rows

यंत्र · THE MACHINE

Built to be taken apart.

Exploded view of the Parakh rover’s 3D model, its twelve part groups separated: wheels, rocker and bogie arms, chassis, mast, sensor head, soil probe and electronics.

TWELVE PARTS, ONE JOB

  1. Wheels ×6 Six 3D-printed hubs in knobby tires — every wheel driven.
  2. Motor pods ×6 130 RPM gearmotors, one per wheel, driven in left/right pairs.
  3. Rocker arms The main suspension levers — they pivot on the chassis, no springs needed.
  4. Bogie arms Trailing V-links that let the middle and rear wheels share every bump.
  5. Differential bar Ties the two rockers together so the body tilts half as much as the terrain.
  6. Chassis & cage The printed PLA backbone — tub, roll cage, and the gold mylar wrap.
  7. Top deck A screwed-down lid that keeps dust off the electronics.
  8. Electronics bay ESP32 brain, twin L298N motor drivers, and the 18650 pack.
  9. Breadboard & solar Prototyping surface on deck, solar assist for longer days.
  10. Mast & rack A servo-driven rack-and-pinion that raises and lowers the sensor head.
  11. Sensor head Ultrasonic eyes for obstacles — and the camera that watches leaves.
  12. Soil probe Drops into the bed to read the soil the crop actually stands in.

काम · HOW IT WORKS

A scouting pass,
from wheels to WhatsApp.

01 — DRIVE

Six wheels, always planted

Rocker-bogie suspension — the same geometry planetary rovers use — keeps all six wheels on the ground over furrows and ridges, with no springs to sag or snap. Six 130 RPM gearmotors, driven through twin L298N drivers, skid-steer it between rows.

02 — SEE

A camera that knows leaves

The onboard camera photographs foliage as the rover passes. A crop-disease detection model — the same line of research behind the PAU field trials — flags suspect plants. On-device inference is in development, so it can work with no signal at all.

03 — PROBE

Reading the ground itself

A servo-driven rack-and-pinion lowers the soil probe into the bed: moisture today, pH next. A BME280 and MQ135 log temperature, humidity, pressure and air quality alongside — the microclimate every diagnosis needs for context.

04 — REPORT

Telemetry off the field

The ESP32 serves its own Wi-Fi hotspot with a live control page, and streams telemetry off the rover — so a scouting pass ends as a field report you can act on, not a hunch.

भीतर · UNDER THE HOOD

Nothing exotic.
That’s the point.

STRUCTURE
3D-printed PLA · 0.2 mm layers · 20% infill
SUSPENSION
Rocker-bogie + differential bar · six wheels
DRIVE
6× 130 RPM DC gearmotors · 2× L298N · skid steer
BRAIN
ESP32 · Arduino toolchain · Wi-Fi AP + telemetry
SENSING
Camera · HD-38 soil · BME280 · MQ135 · MPU6050 · HC-SR04
MAST
SG90 rack-and-pinion · raises the eyes, lowers the probe
POWER
18650 Li-ion pack · solar-assisted charging

BILL OF MATERIALS — AS SOURCED

PLA filament, 1 kg$20
ESP32 development kit$10
DC gearmotors, 130 RPM ×6$24
L298N motor drivers ×2$8
SG90 micro servos ×2$8
GY-BME280 environment sensor$25
HC-SR04 ultrasonic sensor$4
GY-521 MPU6050 IMU$6
MQ135 air-quality sensor$10
HD-38 soil-moisture probe$3
All in≈ $120

Repairable, hackable, and cheap enough to matter — a farmer shouldn’t need a grant to afford a scout.

आगे · WHAT’S NEXT

Direction, not promises.

  1. 01

    On-device inference

    Run the disease model on the rover itself — no connectivity required in the field.

  2. 02

    Soil pH hardware

    A pH probe beside the moisture sensor, to catch soil anomalies a leaf can’t show.

  3. 03

    Wider field trials

    Take the rover to the fields already in the PAU WhatsApp-bot programme.

  4. 04

    Row autonomy

    Waypoint navigation, so a scouting pass doesn’t need a driver.

संपर्क · CONTACT

Built by Aarav Goyal.

Aarav is a student at GEMS Modern Academy, Dubai, who would rather print, wire and flash a rover than watch one on TV. The mechanical platform, electronics and firmware are his; the disease-model research continues with Punjab Agricultural University.

aaravgoyaldxb@gmail.com aaravgoyal.me →