Which Raspberry Pi does the WQM-1 run on?

The shipped host is the Raspberry Pi Zero 2W, and that is the board the Python firmware is built and tested on. The board is a 120 × 105 mm carrier that stacks on the standard 40-pin header — larger than the Raspberry Pi HAT outline; other 40-pin Pi models are not part of our test matrix.

Can I use it with an Arduino?

The datasheet lists Arduino UNO Q / VENTUNO Q as digital-first hosts — the RS485 Modbus probes and the relay side. The analog ADC path and the Python firmware, SQLite buffering and cloud client are the Raspberry Pi's. If you want the full stack, start with the Pi.

Is the firmware open?

The firmware and its documentation live in the public repository at github.com/BlueSignal-XYZ/wqm-1. Start with docs/getting-started.md.

What happens when the network is down?

Readings are written to SQLite on the microSD card first and uploaded when the link returns — over Wi-Fi to BlueSignal Cloud; the LoRaWAN radio is on the board. Nothing is dropped for lack of a connection.

pH, TDS and turbidity on the analog channels through the 16-bit ADS1115, a DS18B20 temperature probe, and RS485 Modbus probes for chlorine, EC/salinity and digital ORP. Ranges and calibration per channel are on the sensor reference.

Is the WQM-1 sold as a bare board?

No. The WQM-1 is sold as an installed unit, quoted per site.

For developers

The water quality HAT for Raspberry Pi.

WQM-1 is a 120 × 105 mm carrier board that puts a 16-bit ADC, a LoRaWAN radio, GPS and four relay outputs under a Raspberry Pi Zero 2W. pH, TDS and turbidity on the analog side, temperature on 1-Wire; chlorine, salinity and digital ORP over RS485. Python firmware, SQLite on the card, source on GitHub.

Get the board Read the docs Full datasheet

Works with Raspberry Pi

Names and logos belong to their owners and are used for identification only. Listing means technical compatibility or use, not endorsement, sponsorship or partnership.

What is on the board

Host & form factor

Form factorCarrier board, 120 × 105 mm, stacks on the Pi Zero 2W 40-pin header

Host boardsRaspberry Pi Zero 2W · Arduino UNO Q / VENTUNO Q (digital-first)

ProcessorBCM2710A1 Quad Cortex‑A53

OSRaspberry Pi OS Lite

StoragemicroSD + SQLite WAL

Sensing

ADCADS1115 16-bit · 4‑ch

Analog channels3 (pH, TDS, turbidity) via 16-bit ADS1115 · temperature on 1-Wire

Digital expansionRS485 Modbus — chlorine, EC/salinity, digital ORP (Honde probes)

Sample interval60 s (cloud-configurable 5–3600 s) · Wi-Fi store-and-forward

CalibrationpH, TDS and turbidity calibrated in the field with standard buffers and the guided wizard; temperature factory calibrated

Radio & position

TransceiverSemtech SX1262

ProtocolLoRaWAN 1.0.3 Class A

Frequency915 MHz (US) / 868 MHz (EU)

PayloadCayenne LPP

GPSu-blox MAX-M10S GNSS

Power & I/O

Input voltage24 V DC, 2 A minimum

Connector2-pos 5.08 mm screw terminal

RelaysFour outputs — switch site equipment through installer-supplied gear

ExpansionI²C · 3.3 V · JST‑XH

EnclosureOptional enclosure; ingress rating per the enclosure supplier’s datasheet

Raspberry Pi or Arduino?

Both can read a pH probe. The difference is everything that happens after the reading.

Raspberry Pi Zero 2W — the native host

Full Linux, so the firmware is Python you can read and change.
SQLite on the card buffers every sample through an outage.
Wi-Fi uplink to BlueSignal Cloud; the LoRaWAN radio is on the board.
Threshold logic runs on the device, so the four relay outputs still switch installer-supplied gear when the link is down.

Arduino UNO Q / VENTUNO Q — digital-first

Listed on the datasheet as a host for the digital side: RS485 Modbus probes and the relay.
The analog ADC path, the Python firmware and the cloud client are the Pi’s.
Pick this when the WQM-1 is a peripheral in a sketch you already have.
Pick the Pi when the WQM-1 is the system.

From unboxing to first reading

Seat the board on the Pi Zero 2W’s 40-pin header and power it from 24 V DC on the screw terminal.
Flash Raspberry Pi OS Lite, clone the repository and follow getting-started.md.
Plug in the probes — pH, TDS and turbidity on the analog channels, the DS18B20 for temperature, RS485 for chlorine, salinity or digital ORP.
Watch the readings land — every 60 seconds into SQLite, every five minutes over LoRaWAN, and live on cloud.bluesignal.xyz once the unit is claimed.

Questions developers ask

Which Raspberry Pi does the WQM-1 run on?: The shipped host is the Raspberry Pi Zero 2W, and that is the board the Python firmware is built and tested on. The board is a 120 × 105 mm carrier that stacks on the standard 40-pin header — larger than the Raspberry Pi HAT outline; other 40-pin Pi models are not part of our test matrix.
Can I use it with an Arduino?: The datasheet lists Arduino UNO Q / VENTUNO Q as digital-first hosts — the RS485 Modbus probes and the relay side. The analog ADC path and the Python firmware, SQLite buffering and cloud client are the Raspberry Pi's. If you want the full stack, start with the Pi.
Is the firmware open?: The firmware and its documentation live in the public repository at github.com/BlueSignal-XYZ/wqm-1. Start with docs/getting-started.md.
What happens when the network is down?: Readings are written to SQLite on the microSD card first and uploaded when the link returns — over Wi-Fi to BlueSignal Cloud; the LoRaWAN radio is on the board. Nothing is dropped for lack of a connection.
What probes plug in?: pH, TDS and turbidity on the analog channels through the 16-bit ADS1115, a DS18B20 temperature probe, and RS485 Modbus probes for chlorine, EC/salinity and digital ORP. Ranges and calibration per channel are on the sensor reference.
Is the WQM-1 sold as a bare board?: No. The WQM-1 is sold as an installed unit, quoted per site.

Get the board Every channel, with ranges