SmartBin and dispenser screens · PackBack Network
Returning a cup should take less time than finding a bin.
The screens, lights and sounds on PackBack's return machines and the new hands-free dispenser. Designed for someone in a hurry, holding a cup, who has never used one before.
- Role
- Product Lead, interaction design
- Company
- PackBack Network
- Timeline
- Feb to May 2026
- Team
- 1 product designer, 2 firmware engineers, 1 front-end engineer, hardware partner
- Platforms
- 7-inch machine touchscreen, LED ring, Card terminal, Sound
1One message per screen, readable from 1.5 m
2Says where the money goes, and when
3Light colour matches the screen state for people not looking at it
9.8 s → 4.6 s
Median time from cup in hand to refund
−58%
Returns that failed or were abandoned
−71%
Support messages about refunds
6 s
Median time to borrow a cup, hands-free
The problem
People walked away from SmartBins without knowing if their cup was accepted or if they'd get their deposit back. The screen showed a lot of text, the lights meant nothing, and every error looked the same.
What I did
I spent three weeks watching people use machines at a station, a campus and a stadium, then redesigned every screen state, the LED ring behaviour, the sounds and the refund flow, and tested them on live machines.
What changed
The median return now takes 4.6 seconds instead of 9.8. Failed or abandoned returns dropped by 58%, and refund questions to support fell by 71%.
01 · Context
A screen people read for about two seconds.
A SmartBin is a return machine about the size of a large bin. You put a used cup in the slot, it reads the cup's QR code, and your deposit goes back to the card you paid with. There's a 7-inch touchscreen on top, an LED ring around the slot and, on newer units, a card terminal.
Most people who use one have never seen it before. They're at a station between trains, leaving a lecture, or walking out of a stadium with 30,000 other people. They read the screen for a second or two, from about a metre away, often with a phone or a bag in the other hand.
- 01ApproachSees the machine, decides if it's for them
- 02Insert cupFinds the slot, cup in any orientation
- 03ScanQR read, cup checked against the network
- 04RefundDeposit back to the card, or tap a card
- 05Walk awayNeeds to know it worked without looking back
Where most failures happened before the redesign
02 · Problem
People didn't know if it worked.
The original screen was designed like a small web page. It had a paragraph of instructions, a counter, a logo and a QR code for more information. When something went wrong, it showed the same red message for every kind of error.
Our support inbox told the rest. A third of all messages were some version of 'did I get my deposit back?'. In video from three locations, 14% of people stood at the machine after inserting a cup, waiting for something to happen, and then left without knowing.
The original machine
- ✕45 words of instructions on the idle screen
- ✕LED ring blue all the time, whatever happened
- ✕One red error message for six different problems
- ✕No mention of where the refund goes or when
After the redesign
- ✓Five words and a picture of the slot
- ✓LED colour matches the screen state
- ✓Six specific states, each with a next step
- ✓Refund amount, card ending and timing on screen
The question we worked on
How might we make a return feel finished, so people walk away certain it worked, in under five seconds?
03 · Research
Three weeks standing next to machines.
I spent three weeks at a station kiosk, a university food court and two match days at a stadium. I timed 312 returns with a stopwatch, interviewed 41 people right after they used a machine, and reviewed two weeks of machine logs with our firmware engineers.
Nobody reads after the cup goes in
Once the cup leaves their hand, people turn away. Anything we show after that moment needs to work in peripheral vision, which means light and sound.
“I put it in and just walked. Did it work?”
The refund is the real reward
Most people cared more about getting their €1 back than about saving the planet. Not saying where the money goes made them anxious.
“Where does the euro go? To my card? Which card?”
Errors need a way out
When a bin was full, people tried three or four times, then left the cup on top. They didn't know another machine was 40 metres away.
“It just says error. Okay, so what now?”
04 · Process
Designing for a machine you can't update by Friday.
Machine software ships less often than web software, and a bad update reaches hundreds of units in public places. So we prototyped on real machines from week two, using a test build the firmware team could flash in a few minutes, and tested every change at one location before it went anywhere else.
Animated video instructions
Nice in the showroom. On site, nobody watched long enough for the loop to make sense, and it slowed down older machines.
Text-led screens
Clear when people stopped to read, which was rarely. Kept for the error states, where people do stop.
One big icon, five words, matching light
Readable in a glance, and the LED ring repeats the message for people already walking away.
05 · Design decisions
Six states, one message each.
Every state gets one message and one colour
We reduced everything the machine can do to six states. Each has a single headline of five words or fewer, a large icon, one line of detail and an LED colour. White means ready, purple means working, green means done, amber means try something else, red means the machine needs help.
Error states always end with what to do next. A full bin points to the nearest SmartBin, with the distance. A cup from another system tells you to use a normal bin, so people stop trying.
The light does the talking once you've turned away
The research was clear that people stop looking at the screen the moment the cup leaves their hand. So the LED ring around the slot became the main feedback. It turns green with a short two-note sound when the cup is accepted. You see it from the corner of your eye while walking away.
We tested sound carefully. In stadiums it's useless, at a quiet campus it's welcome, so volume adapts to ambient noise measured by the machine's microphone. The microphone never records, it only reads a noise level.
| State | Screen | LED ring | Sound |
|---|---|---|---|
| Ready | Place your cup here | Soft white, breathing | None |
| Checking | Checking your cup | Purple, chasing | None |
| Accepted | Cup returned | Green for 3 s | Two rising notes |
| Not ours | This cup isn't ours | Amber, steady | One low note |
| Full | This bin is full | Amber, slow pulse | One low note |
| Offline | Returns still work | White, normal | None |
Say where the money goes, and when
The success screen now says the amount, the last four digits of the card and the timing in one line: '€1.00 is on its way to your card ···4417'. On machines with a card terminal, the refund happens right there, and the terminal and screen show the same step numbers so you know where you are.
When the machine is offline, it still accepts cups and tells you the refund will arrive within 24 hours. Hiding the delay is what caused most of the angry support messages before.
A dispenser you never have to touch
In April 2026 we introduced a hands-free SmartDispenser built with our hardware partner. You tap a payment card or tag, a light ring guides you, and a cup drops into your hand. No screen at all, so the light and sound language had to carry the whole interaction.
We reused the same colours as the SmartBin on purpose. Purple means working, green means take your cup. People who had returned a cup before needed no instructions to borrow one.
06 · Edge cases
What happens when it goes wrong in public.
Reads anyway
We added a second QR code on the base of new cups, so orientation stopped mattering.
Accepted, lid flagged
The cup is accepted and the wash partner removes the lid. Refusing it caused more litter.
Refund saved for later
The return is logged against the cup. The person can claim it on the PackPerks page with their card.
Faster reset
Success clears after 3 seconds instead of 8, with a progress line so people know when it's their turn.
Safe shutdown
Cups already inside are logged when power returns, and the refund still goes out.
Light still works
The LED ring can run the whole interaction on its own, which saved two vandalised units at a station.
07 · Outcome
Faster returns, and fewer people wondering.
The new software reached every SmartBin in May 2026. Returns got faster mostly because people no longer waited for confirmation. They saw the green ring and left.
“Green light, done. I didn't even stop walking.”
“Since the update I mostly get questions about where to buy the cups, not about refunds.”
“The bin told me there was another one by the stairs. That's all I needed.”
08 · Reflection
What I learned from a two-second interface.
Industrial design school taught me that people use objects with their whole body. This was the first software project where that mattered more than anything on the screen.
If I did it again, I'd involve the cleaning and facilities staff from day one. They see every failed return and every cup left on top of a bin, and two of our best ideas came from a cleaner at the station.
What's next
- ·Arabic and English screens for the first machines in the Gulf, designed with the same six states
- ·A stadium mode with a bigger counter and faster resets for match days
- ·Using the LED ring for accessibility, including a high-contrast mode for people with low vision
Tools on this project
Figma, ProtoPie, Machine test builds, Stopwatch and a notebook, Video analysis, Dovetail
Names of the people quoted have been changed to protect their privacy.
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