ZOYI Verified on hardware
ZOYI ZT-5566S app
Use your ZOYI ZT-5566S with TestNMeasure: a live Bluetooth readout, graph, logging, CSV export and guided test sequences. The ZT-5566S is a desktop True RMS multimeter with a 19999-count display and Bluetooth.
iOS and Android, beta this winter.

Hardware status
Works with TestNMeasure
| Brand | ZOYI |
|---|---|
| Model | ZT-5566S |
| Connection | Bluetooth LE |
| Status | Verified on hardware |
| The meter | Desktop meter and Bluetooth speaker, 19999 counts, True RMS. |
| In our shop | ZOYI ZT-5566S in the TestNMeasure shop |
Live readings come through the app's ZOYI driver, which uses the protocol of ZOYI's own e-Bull app; the same protocol was checked against a real ZT-5B's display. Each measuring function and Android are still to be checked one by one.
What works today
The app's ZOYI driver reads the ZT-5566S with the same protocol as ZOYI's own e-Bull app. On top of the readout you get the stability bars, a live graph, hold, REL and min/max/avg, all in the app. Capture a reading with one tap, or record over time with notes, photos and voice notes. Everything works offline.

Connect in three steps
- Turn the meter on.
- Turn on the meter's Bluetooth for the app as its manual describes, until the Bluetooth symbol shows on the display.
- In the app, open the device chip and pick Bluetooth DMM.
After a dropped connection the app reconnects to the last meter.
What the meter measures
According to Zotek, the ZT-5566S measures DC voltage up to 1000 V, AC voltage up to 750 V, current up to 20 A, resistance up to 199.99 MΩ, capacitance, frequency, duty cycle, diode and continuity, with auto or manual ranging. It runs on rechargeable batteries and is also a Bluetooth speaker with a clock and alarm. Zotek documents the ZT-5566SE with the same manual. The plain ZT-5566 is a similar desktop meter, but its manual describes Bluetooth for music only, so it is not listed here.
The meter sends its reading and unit about three times a second, and nothing else, so its function, range and hold cannot be set from the phone.
Not verified yet
The ZT-5566S's live readings come through the same ZOYI driver and protocol that matched the ZT-5B's display on hardware. Still to be checked one by one: each measuring function, and the same run on Android. If a reading in the app differs from the meter's display, mail us both readings at support@testnmeasure.app.
What it does and doesn't do (yet)
| What it does | Plan |
|---|---|
| Finds supported Bluetooth meters nearby and lists them, with a clear path when Bluetooth or its permission is missing. | Free |
| Tap a result to connect; the meter becomes the active instrument and live readings start. | Free |
| Reconnects to your last meter on launch and after drops, and always shows the connection state. | Free |
| Keeps a list of your instruments with names you choose, so every reading is tied to the meter that took it. | Free |
| A simulated meter lets you try the whole app without hardware; it is labelled DEMO everywhere. | Free |
| Type the reading from any instrument; typed values are marked as manual. | Free |
| A large readout that shows which digits have settled; OL and UL are shown as OL and UL, never as a number. | Free |
| Swipe the readout to a live graph with min and max lines, pan and zoom. | Free |
| Hold freezes the displayed reading and statistics in the app, independent of the meter's own HOLD. | Free |
| Shows the running minimum, maximum and average since the last reset, with the sample count. | Free |
| Shows rolling averages over the last 5, 30 and 60 seconds. | Free |
| REL shows the difference from a stored reference, for example to null out test-lead resistance. | Free |
| Five stability bars show when a reading is steady. | Free |
| A landscape layout for the meter and run screens. | Free |
| Keeps the screen on while you measure, run a test or record. | Free |
| One tap saves the current reading, with an Undo. | Free |
| Log sessions hold captures and time-series recordings, and recording continues with the screen locked. | Free |
| Add a text note and a short label to any capture. | Free |
| Attach up to 5 photos to a capture. | Free |
| Record a voice note of up to 2 minutes on a capture. | Free |
| Scale readings with a factor and an offset, for clamp adapters, shunts and probe dividers; the raw reading is kept. | Free |
| Search and filter your history; deleted items stay in Recently deleted for 30 days. | Free |
| Review a session as a full graph with pan and zoom, statistics and its captures. | Free |
| Auto-record saves a capture when the reading becomes stable. | Free |
Not yet, or not planned
- One live Bluetooth meter at a time for now; two meters at once (voltage and current, with power) is coming.
Questions
Does the ZT-5566S app work on Android?
Not yet. The ZOYI driver is in the iPhone app first. We will mark Android here when it has been run against the meter.
Can I export ZT-5566S readings to Excel?
CSV export is free and opens in Excel. Excel test reports are free too.
Is the ZT-5566S supported?
Yes, for live readings over Bluetooth, with the same ZOYI driver as the ZT-5B. The list of what is still to be verified is above.
ZOYI and Zotek are trademarks of their owner; TestNMeasure is not affiliated with or endorsed by Zotek.
Coming to iPhone and Android.
iOS and Android, beta this winter.
Questions or a meter to suggest? Mail support@testnmeasure.app.
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