Four streams, one platform.
A four-module design accommodated wine bottles, mason jars, yogurt tubs, and cans. Its conveyor-based architecture established the first complete return system.
← All projectsMaking reuse
Industry project · Circulr · 2024–2026
Making reuse
returnable.
A compact reverse vending machine that accepts reusable containers and turns each return into a grocery-store reward.
Circulr Reverse Vending MachineDesigned, built, programmed, and tested by Aaron Emmanuel.
See the return experience ↓
OwnershipConcept to deployment
FocusMechanics + electronics + software
In-store deploymentOctober 2025
The challenge
Make container returns part of the everyday shop.
Circulr needed a practical way for customers to return reusable packaging in a grocery store. The machine had to validate each return, handle containers carefully, and issue a reward through a straightforward customer interaction.
As the sole engineer building the system, I connected mechanical design, electrical integration, software, fabrication, and testing into one working product.
01 / The return experience
Scan. Return.
Get rewarded.
A guided transaction connects a physical container to a validated refund, with the machine checking the handoff along the way.
- 01
Start
A button begins the return session.
- 02
Scan
The Raspberry Pi checks the barcode against a locally stored list of accepted containers.
- 03
Return
An approved scan unlocks the return gate. Distance sensors monitor the handoff and flag removal or substitution.
- 04
Finish
One printed receipt totals the accepted returns, ready to redeem as a grocery-store discount.
02 / Product evolution
Smaller footprint.
A more focused machine.
The first system explored four return streams. Store feedback and return patterns shaped a simpler, single-module product centered on jars and cans.
Built around the most common returns.
A compact single-module machine reduced the footprint and number of mechanisms. Focusing on jars and cans simplified the return path and made the customer interaction quicker.
03 / Engineering the product
One machine.
Connected disciplines.
Handle reusable containers carefully.
Chute geometry and cushioning were refined through rapid prototypes and repeated testing. The aim was a reliable slide into storage without sticking or damaging glass containers.
Build with proven components.
Off-the-shelf sensors, servo motors, a barcode scanner, and a receipt printer were integrated around a Raspberry Pi. Component choices prioritized cost, availability, and speed to market.
Validate the whole transaction.
Python software manages the approved-barcode list, gate behavior, sensor feedback, item values, and receipt total. A rejected barcode leaves the gate locked; a detected handoff error excludes that item from the refund.
Recover without a manual restart.
Automatic startup, watchdog monitoring, and timeout-triggered restarts were added to address observed software failures and support unattended operation in the store.
04 / In the real world
From the workshop
to Fiesta Farms.
The mini RVM entered operation at Fiesta Farms in Toronto in October 2025. A later update from Circulr reported five months of error-free operation.
Operational update reported by Circulr; not an independently measured uptime statistic.
June 2024 – August 2025Full-time technical lead
Design, integration, build, software development, and testing.
October 2025Retail deployment
Single-module RVM installed at Fiesta Farms.
Through June 2026Continued development and support
Part-time work as an independent contractor following the full-time role.
Designed & built
Aaron Emmanuel · Sole technical lead