Stargaze designed, built, and deployed a fleet of dedicated payment terminals that accept payment without a phone, a register, or a fixed internet line. Each device carries its own embedded SIM for encrypted connectivity and a secure element for on-device authentication, and the entire fleet is provisioned, updated, and monitored remotely from a single cloud platform.
The context
Merchants in retail, food service, markets, courier delivery, and vending increasingly need to take payment at the point of interaction — on a counter, at a stall, at the door — not tethered to a checkout or a cashier's phone. A phone-dependent or Wi-Fi-dependent setup fails exactly where these merchants operate: patchy connectivity, no fixed line, high transaction turnover, and disputes over whether a payment actually landed.
The brief was a self-contained device that (1) works out of the box on cellular, (2) confirms every payment unambiguously in real time, and (3) can be managed across a large, geographically distributed fleet without physical access to each unit.
The solution
The terminal is a compact, battery-powered countertop unit that combines three things in one enclosure: a payment front end (dynamic QR, contactless NFC, and EMV card acceptance), an embedded cellular module with its own SIM, and a secure element that handles PIN entry and device-certificate authentication on the device itself.
The embedded SIM does double duty. It carries the encrypted data session used to authorise each transaction against the payment switch, and it provides an independent SMS channel used for transaction notifications, SMS receipts, and one-time-code (OTP) confirmation — a channel that keeps working even when data signal is weak. This dual-path design is what lets the device operate reliably in low-coverage environments where a data-only or Wi-Fi-only terminal would stall.
How a transaction flows
The merchant enters an amount; the terminal generates a QR code for that exact sum, or the customer taps a card or phone against the NFC reader. The device opens an encrypted session over its cellular link, authorises the payment against the switch, and — within one to two seconds — announces the confirmed amount out loud through its speaker. A push confirmation is delivered from the cloud, and an SMS notification can be sent to the merchant or the customer as a durable record. For online or card-not-present flows, the same SMS channel receives the OTP needed to confirm the operation and can deliver an SMS receipt with a link.
The spoken confirmation plus the SMS record is deliberate: it removes the two most common friction points at the counter — noisy environments where a screen isn't seen, and disputes based on faked "payment successful" screenshots.
Connectivity and the role of the SIM
Every terminal ships with an embedded SIM (physical nano-SIM, with optional eSIM). Connectivity is 4G LTE Cat.1 with 2G/3G fallback, plus Wi-Fi and Bluetooth where a local network is available. The SIM's data path handles cloud authorisation; its SMS path handles notifications and OTP. Because both paths run over the same managed connectivity, the fleet's data usage, activation state, and location profile stay consistent and observable — which matters both operationally and for staying within each carrier's acceptable-use terms.
Security and compliance
Authentication happens on the device: a secure element holds the device certificate and processes PIN entry, so credentials are never exposed to the application layer. Card acceptance follows EMV Level 1 / Level 2, the payment channel is encrypted end to end, and the design is built to PCI-aligned standards. Each unit is uniquely identifiable by its device certificate, which also underpins remote trust when the fleet is managed centrally.
Deployment and fleet management
The whole fleet is operated from a cloud terminal-management system (TMS). New units are provisioned remotely, firmware and configuration are pushed over the air, and transaction statistics and device health are monitored per unit and in aggregate. Because activation, connectivity, and location are all visible from the platform, rollouts can be scaled in controlled waves and kept within agreed daily activation and usage limits — no truck roll, no per-device handling.
Device at a glance
- Form factor
- Compact countertop, ~120 × 75 × 20 mm, ~150 g
- Display
- 2.4″ colour display + dedicated QR screen
- Connectivity
- 4G LTE (Cat.1) with 2G/3G fallback, Wi-Fi, Bluetooth
- SIM
- Nano-SIM (physical) + optional eSIM
- SMS
- Send/receive: transaction alerts, SMS receipts, OTP intake
- Voice confirmation
- 5 W speaker, multilingual amount announcement (MP3/TTS)
- Payment methods
- Dynamic QR, NFC/contactless, EMV cards, barcode
- Supported schemes
- Alipay, WeChat Pay, UnionPay, SBP, UPI, Visa, Mastercard
- Processor / OS
- ARM Cortex-A, Android / Linux (by version)
- Scanner
- Integrated camera / QR & barcode scanner
- Security
- EMV L1/L2, PCI-aligned, encrypted channel
- Power
- 2500 mAh Li-ion, USB-C charging
- Management
- Cloud TMS: remote setup, OTA updates, analytics
- Certifications
- CE, FCC, RoHS, EMV
What it delivers
A merchant can take payment anywhere there is cellular coverage, confirm it out loud and by SMS in real time, and issue a digital receipt — with no phone, register, or fixed line involved. For the operator, a single cloud platform provisions and monitors the entire fleet, scales rollouts in controlled waves, and keeps connectivity usage consistent and within policy.
- Embedded connectivity
- On-device security
- QR · NFC · EMV
- Voice + SMS confirmation
- Remote fleet management
- Scales in controlled waves
Stargaze Tech Inc. — systems designed, built, and delivered in-house.