Do I need a SIM card in every node?

No. One 4G LTE dongle plugs into the USB-A port on a single node and creates a WiFi hotspot. All other nodes connect as WiFi clients. Use a TP-Link or similar repeater to extend coverage across zones. One SIM, one data plan, for the whole orchard.

Why does the Sankhya node use LiFePO4 instead of Li-ion?

LiFePO4 is significantly safer for unattended outdoor deployment with no thermal runaway risk at high temperatures. It has a flat discharge curve keeping voltage stable until nearly empty, and the internal BMS handles charge ceiling so no separate solar charge controller is needed.

How do I order the Sankhya carrier board from JLCPCB?

Download the Gerbers zip, extract it, and upload the inner Gerbers.zip to jlcpcb.com. Select 2 layers, FR4, 1.6mm, HASL. Enable PCB Assembly and upload BOM.csv and PickAndPlace.csv. The Waveshare ESP32-S3-Nano sockets in after delivery and must be soldered.

Open Hardware v1 (deprecated) — Sankhya Intelligence Carrier Board

Q: Why is the Sankhya Intelligence hardware open source?

The hardware is commodity — the BOM is standard components from LCSC. The proprietary value of Sankhya Intelligence is the per-tree longitudinal dataset, the uptake index model, and the agronomic AI layer, all of which run server-side. Publishing the hardware removes the adoption barrier and turns transparency into a competitive advantage.

Board renders

Carrier Board v1

Designed in EasyEDA. Manufactured and assembled by JLCPCB. 2-layer FR4, approximately 100 × 80 mm. Gerbers, BOM with LCSC part numbers, and PickAndPlace file included in the download.

Sankhya Intelligence Carrier Board v1 — back showing Waveshare ESP32-S3-Nano socket footprint

Sankhya Intelligence Carrier Board v1 — PCB layout routing view in EasyEDA

Sankhya Intelligence Carrier Board v1 — full schematic EasyEDA REV 1.0 showing all subsystems

Physical specs

Form factor: 100 × 71 mm, 2-layer FR4 1.6 mm, RoHS compliant

Weight: ~25g (PCB only; ~400g with battery and dongle)

Operating temperature: −10°C to +70°C (extended range variants available on request)

Enclosure: 200 × 155 × 80 mm IP67 ABS weatherproof + cable glands + silicone sealant

Power system

Input: 12V LiFePO₄ battery (12.8V nominal, 6Ah, internal BMS)

Solar charging: 20W panel (12V nominal, Voc ≤22V, Isc ≤1.5A) with Schottky blocking diode

Autonomy: 15–20 days at midnight-to-sunrise monsoon with zero sun

Regulator 1: LM2596S 12V → 5V, 3A continuous, ≤0.5°C drift 0–60°C ambient

Regulator 2: LM2596S 12V → 3.3V, 3A continuous, for ESP32 & sensors

Switching losses: Combined 5V + 3.3V rails: ~2–3W @ full WiFi load

Battery monitor: INA219 current-sense on 12V rail; logs total consumed kWh, peak current, battery health via I²C

MCU & radio

Processor: Espressif ESP32-S3-WROOM-1U (single-core at 240 MHz, dual-core variant available)

PSRAM: 8 MB octal SPI for large buffers (logging, JSON parsing, OTA staging)

Flash: 16 MB for firmware + OTA rollback + filesystem

WiFi: 802.11b/g/n, −10 to +20 dBm TX, connects to TP-Link repeater mesh or local hotspot

Antenna: External U.FL 2.4 GHz for above-canopy mounting; 5 dBi omnidirectional

Sleep current: 10 μA in deep sleep (RTC on, PSRAM retained)

Sensor interface

Bus: RS-485 Modbus RTU (half-duplex), 4800 baud, 8/N/1

Transceiver: MAX485 / SP3485 with hardware direction control (GPIO5 drives DE+RE)

Termination: 120 Ω resistor at end of sensor chain; hardware switch for branch termination

Sensor capacity: Up to 3 sensors per node (RS-485 slave IDs 1–3), or daisy-chained with higher IDs

Sensor power: Switched 12V via Q1 (TPS1H100B), controlled by GPIO18 for power-down cycles

Sensor reading interval: Configurable 1–60 minutes (firmware selectable, typically 1 hour)

4G connectivity

Dongle: Any USB-A 4G LTE modem with tethering (tested: Quectel EC200U-EU, Huawei)

Power path: USB-A 5V from LM2596S 5V rail, switched via Q2 (GPIO17)

WiFi hotspot: Dongle creates SSID; TP-Link repeater extends to all other nodes

Data plan: One SIM card, shared across entire orchard via WiFi mesh (single point of failure, by design)

Bandwidth: ~5 MB/month per 50 nodes with 1-hour reading interval + AI chat

Firmware & updates

Base: Arduino SDK 2.x, ESP32 board package 2.0.18

Flash method: USB-C Web Serial API at flash.sankhyafarms.com (no IDE, no drivers)

OTA updates: Cloudflare Workers `/ota/check` endpoint; nodes auto-update on boot if newer version exists

Firmware size: ~550 KB (Haiku AI inference offline on node via TFLite, fallback to server)

Rollback: ESP32 dual-OTA partition with automatic revert on failed boot

Communications

Reporting: POST to Cloudflare Worker endpoint; includes sensor readings, battery voltage, WiFi RSSI, uptime

Report format: JSON gzip-compressed for metered 4G

Cadence: 1 report per sensor reading cycle (typically 1/hour); optional longer intervals in battery-saver mode

Latency: Sub-second from WiFi to Cloudflare D1 database (no serial polling delay)

Data retention: 2 years of historical sensor data + images + agronomic insights in Sankhya dashboard

Deployment notes

Installation: Weatherproof enclosure with cable glands for barrel jack, RS-485 sensor terminals, and antenna feedthrough. Mounting: wall-mount or pole-mount at orchard periphery for WiFi coverage and sunlight.

Sensors: ZTS-3002 7-in-1 (moisture, EC, pH, temp), JXC-LS-RS232 or equivalent RS-485 Modbus. See sensor compatibility list →

Sunlight: 20W panel provides 15–20 days monsoon reserve; plan for 4–6 hours peak sun/day in Patdi region (adjust for local climate)

Mesh network: TP-Link TL-WR845N repeater covers 4+ nodes per repeater in open orchard with line-of-sight to a master node running 4G hotspot

Enclosure sealing: Cable glands + silicone sealant prevent water ingress during irrigation spray. Inspect quarterly for mold/corrosion in monsoon.

For advanced debugging or custom sensor configurations, open a support ticket at sankhyafarms.com/contact

Function	GPIO	Arduino label	Connected to
RS-485 RX	GPIO44	D0	MAX485 RO — Receive Output
RS-485 TX	GPIO43	D1	MAX485 DI — Data Input
RS-485 Direction (DE/RE)	GPIO5	D2	MAX485 DE + RE tied together
Sensor 12V switch	GPIO18	D9	Q1 gate — switches 12V to soil sensors
USB-A 5V switch	GPIO17	D8	Q2 gate — switches 5V to USB-A port
INA219 SDA	GPIO11	A4	Battery monitor I²C data
INA219 SCL	GPIO12	A5	Battery monitor I²C clock

Platform capabilities

What one node can do.

The board is the edge. The intelligence lives server-side on Cloudflare's global edge and compounds with every season of data.

📡

Up to 3 sensors per node

Three RS-485 terminal blocks wired in parallel — daisy-chain sensors without splicing. Each sensor has its own Modbus slave ID. Mix soil EC/pH/moisture, ambient temperature, or any RS-485 Modbus device. See compatible sensor list →

🌐

WiFi mesh — one SIM, whole orchard

One 4G LTE dongle in one node creates a WiFi hotspot. A TP-Link repeater extends coverage across all irrigation zones. Every other node connects as a WiFi client — one SIM card, one data plan, covers the whole orchard.

☀️

Solar + LiFePO₄ — 15–20 day reserve

20W solar panel charges a 12.8V LiFePO₄ battery with internal BMS. No separate charge controller needed. Deep sleep between hourly reading cycles provides 15–20 days of monsoon autonomy with zero sun exposure.

🔄

Over-the-air firmware updates

Nodes query a Cloudflare Worker on each wake cycle. Updates arrive as signed presigned URLs and flash via esp_https_ota() with automatic rollback on failure. Deployed nodes never need physical access for firmware updates.

🌳

Per-tree AI agronomic intelligence

Sensor data feeds the Sankhya Intelligence platform — a dual-model AI stack (Haiku for fast auditing, Sonnet for deep analysis) generating per-tree fertigation prescriptions from longitudinal soil history, not generic crop tables.

⚡

Browser-based firmware flashing

No IDE, no USB drivers. flash.sankhyafarms.com uses the Web Serial API — plug in via USB-C, select your sensor configuration from the dropdown, and flash in under a minute. Works in Chrome on any operating system.

Ordering guide — JLCPCB

How to order your own boards.

The download contains everything JLCPCB needs for a bare PCB or fully assembled (PCBA) order. A video walkthrough is coming — follow these steps in the meantime.

Download and extract the zip

Download Sankhya_Intelligence_PCB_Gerbers v1 41526.zip and extract it. Inside you will find three files: Gerbers.zip, BOM.csv, and PickAndPlace.csv.

Upload Gerbers.zip to JLCPCB

Go to jlcpcb.com → Quote Now → upload Gerbers.zip (the inner zip, not the outer one you just extracted). JLCPCB auto-detects board dimensions. Select: 2 layers, FR4, 1.6 mm thickness, HASL surface finish, your preferred quantity.

5 boards typically cost under $10 + shipping. Minimum order is 5 pieces.

Enable PCB Assembly (PCBA) — optional but recommended

Toggle PCB Assembly on the same order page. Upload BOM.csv and PickAndPlace.csv when prompted. JLCPCB will source and solder all SMD components from LCSC. Through-hole parts (terminal blocks, barrel jack, USB-A port) are not assembled by PCBA — you solder those yourself.

The Waveshare ESP32-S3-Nano is not included in the PCBA — it sockets into the board after delivery.

Socket and solder the ESP32-S3-Nano

The Nano plugs into the 2×female 2.54 mm headers on the back of the board. Solder it in — friction fit alone will fail under vibration and thermal cycling in a field enclosure. Use the Waveshare ESP32-S3-Nano specifically — pin spacing and GPIO numbering differ from other Nano-form-factor modules.

Flash firmware and register your node

Visit flash.sankhyafarms.com, connect via USB-C, select your sensor configuration, and flash. Then register the node with your Sankhya Intelligence account to begin continuous per-tree soil data collection and AI analysis.

Frequently asked questions

FAQ

No. One 4G LTE dongle plugs into the USB-A port on a single designated node and creates a WiFi hotspot. All other nodes connect to that hotspot as WiFi clients. Use a TP-Link TL-WR845N or similar repeater to extend coverage across all irrigation zones. One SIM card and one data plan serves the whole orchard.

The USB-A port carries 5V and GND only — there are no data lines connected to the ESP32. It exists solely to power a 4G LTE WiFi dongle. Storage devices, keyboards, or any USB data device will not function. If you are within range of existing WiFi infrastructure, no dongle is needed at all — the ESP32 connects directly to any WiFi network.

LiFePO₄ is significantly safer for unattended outdoor deployment — no thermal runaway risk at high temperatures inside a sealed enclosure in direct sun. It also has a flat discharge curve, keeping voltage stable until nearly empty, which makes battery state-of-charge estimation more reliable. The internal BMS handles charge ceiling so no separate solar charge controller is needed.

The LiFePO₄ battery's internal BMS acts as the charge ceiling — it disconnects charge input when full. An SS34 Schottky diode between the solar panel and battery prevents backfeed current at night. This is fully sufficient for 20W panel wattage. A dedicated MPPT controller adds cost and complexity for marginal efficiency gain at this scale.

If your sensor speaks Modbus RTU over RS-485, it will physically work with this board. The Sankhya Intelligence platform requires a verified register map to parse sensor data correctly. If your sensor is not in our sensor library, send us the datasheet — if it speaks Modbus RTU we can add support within days.

That is the EasyEDA account username of Engr. Kashif, the PCB designer who produced this board under a work-for-hire commission. The Gerber files, BOM, and PickAndPlace CSV contain no personal identifying information and are safe to use directly with JLCPCB.

Because the hardware is genuinely not the hard part. The BOM is commodity components from LCSC that anyone can order. What takes years to build is the per-tree longitudinal dataset, the uptake index model, and the agronomic AI layer — all of which run entirely server-side. Publishing the hardware removes the adoption barrier, enables self-installation, and turns transparency into a competitive signal. Fasal does not do this. Netafim certainly does not.

The hardware is open.
The intelligence isn't.