SMART FIRMWARE FOR YOUR RS-232 SCALE

BOARD (ABOUT 13.50 EUR)
+ PRO LICENCE 46.50 EUR
= ABOUT 60 EUR
PRO OR ENTERPRISE: ONCE - NO SUBSCRIPTION - WORKS OFFLINE FOR EVER

Packers and small manufacturers

Check-weighing with statistics (Cp/Cpk), ℮ lot checks with the EU sample plans and a lot report for the inspector, piece counting, sorting into your own classes, filling with machine control - on your verified scale, without a PC.

Shops, market stalls and farm shops

Weigh, price and print the label in one step. Every sale goes into the sales log on the adapter, by day and product, with a CSV file for your accountant.

Bakeries and food producers

Recipes weighed step by step with tolerances, also across two scales (kilos on the platform scale, grams on the fine scale), with costs per batch, lots and labels with allergens and nutrition values.

Bars, stores and workshops

Stock counted by weight, loss against what went out, and the same numbers on every phone of the team.

Everyone with a scale

The scale self-check with a report, long-term recordings with alarms, several phones on one scale and several scales in one program.

The smart upgrade for verified scales

You sell by weight or pack ℮ prepackages? Then you need a verified (legal for trade) scale - and you probably have one already. Plug the adapter into its RS-232 port and your verified scale gets the whole app: the ℮ prepackage control (EU 76/211/EEC and German FPackV) with mean, T1 and T2, the sample plan for your lot size and a printable lot report with your company header, check-weighing with tolerances, statistics with run chart, histogram and Cp/Cpk, counting, factory filling, recipes - and your own labels with the net weight, price and EAN barcode, printed straight to your label printer. Sell from the same scale? The sales log adds up every sale per product and day (revenue, costs, profit) and the inventory keeps your stock - your verified scale is then also a small sales computer (your own record, not a certified cash register - even if it does the same! ;-)).

The interfaces that scale makers sell for their verified scales (USB, network, wireless) often cost a lot - and come with no software at all: you still need a PC and an expensive program before you can do anything with the weight. The adapter is a small plug - and the app is already included, on your phone, tablet or laptop.

LISTEN ONLY: your scale stays as it is

Switch on LISTEN ONLY and the adapter only reads the data from the serial port of your scale. It never sends anything to the scale - no weight requests, no tare signals - and changes nothing in it. (Many verified scales have a protective interface that also allows requests or tare - check the manual of your scale.)

EXACT WEIGHT: the value of your scale

With EXACT WEIGHT the app shows exactly the weight your scale sends - no averages, no lock, no zero tracking of ours - and takes its own stable mark (METTLER TOLEDO, KERN, A&D, ADAM, OHAUS...). What your scale shows, the app shows (minus a tare you set in the app).

EXTRA LINE: the alibi number on your label

If your scale prints an extra line with its print key (e.g. the alibi number of a verified scale), tell the app how it starts: the line is not read as a weight and can be put on your labels with [scaleline]. It only reads - it works with LISTEN ONLY too.

And what is legal?

The display of your verified scale stays the legal reading - the app itself is not verified. For ℮ packs the label shows the nominal quantity, the filling is checked with your verified scale and the app keeps your records. Weight or price labels in trade (variable-weight packs, price tags, receipts) are legally relevant: ask your verification office (in Germany the Eichamt) which setup is allowed - the usual way for PC software is a scale with an alibi memory. Check the rules of your country. All in one place: LEGAL FOR TRADE in the manual.

Any scale with an RS-232 port

RS-232 Serial Port:

If your scale have a port like that - then no worries, the adapter will work with it! Independentless of the capacity and precision of your scale - from kilos to milligrams - we will make it smart and mobile!

Presets & auto-detect:

Select the maker of your scale - METTLER TOLEDO (MT-SICS), KERN (KCP), OHAUS, A&D, ADAM or SARTORIUS (SBI) - and the adapter speaks its protocol: it starts the weight stream or asks for the weight by itself, and skips error and overload answers. You don't know the baud rate? Press 🔍 AUTO-DETECT and the adapter finds it (with the data bits and parity) in about 10 seconds.

List prices of common products, found in October 2026, rounded, without shipping. Each of them covers one job - UP↑SCALE covers all of them for the same price, and firmware updates stay free.

What is in which version?

FREE version	PRO version 46.50 EUR once	ENTERPRISE & COMPLIANCE 121.30 EUR once (upgrade from PRO 74.80 EUR)
weighing in all units, tare, prices, volumes, counting, simple check-weighing (zero check), recipes	everything of the free version	everything of PRO
all connections: several phones and computers, ESP-NOW devices, 1 extra scale	more extra scales (stations)	everything of PRO
free trial (in a row, then a 10-minute pause of that mode): extended check-weighing (20 items), sorting (20 items), factory mode (10 fills), tracking (15 minutes), density (3), sales log (20 sales), inventory (5 items)	all of them without limits	everything of PRO
statistics, ℮ prepackage control and the scale self-check on the screen	℮ lot report and sales report (print, save)	printable test reports (PDF/HTML) and the final report of the test suite, all CSV exports (tests, sales, statistics, stock, tracking)
labels (PNG, browser print) with a small "FREE VERSION" line	clean labels, label printers directly	everything of PRO
up to 3 THINGS and 1 recipe on the scale	up to 1000 THINGS and 250 recipes	everything of PRO
-	-	equipment register with due dates, test history on the scale with trend, users (up to 50, ADMIN, optional passwords, login instead of a scale password), an activity log (last 300 events with the user), ADMIN protection for deleting and settings, report extras (company header, logo, running report number, integrity code) and exports in your format

Why trials and short pauses?

The free version is free forever, with no time limit. For most purposes (weighing, counting, price calculating and much, much more) the free app is already enough - maybe you never need to upgrade at all! We want you to test everything properly with your own scale before you buy: every PRO mode runs for a few items in a row, then only that mode takes a 10-minute break - weighing, counting and everything else keep working. Sorry for these little interruptions: they are the only way for us to keep the free version this complete. PRO pays for the development of UP↑SCALE - no ads, no subscription, no data collection.

Your licence - simply explained

You buy the PRO licence (or ENTERPRISE & COMPLIANCE) once. It is made for your board (its Device ID) and works on it forever - no subscription, no account, no internet needed, also completely offline. Every phone, tablet and computer that connects to your adapter gets the unlocked version. The same is true for ENTERPRISE & COMPLIANCE: once, forever, offline. Updates of the firmware and the app stay free. Your board broke? You get a replacement licence for the new board.

1. Buy the board: the ESP32-C3 RS232 Adapter at TinyTronics (about 13.50 EUR + shipping).
2. Install our free firmware from your computer - see first install below.
3. Try it: connect it to your scale and open our app. The free version runs as long as you like.
4. Get your licence (only when you want more): order the PRO licence (46.50 EUR incl. VAT) with the Device ID of your board. To find it: connect the board in the app, tap ⭐ FREE VERSION - UPGRADE TO PRO below the title (or SCALE ✰ INFO at the bottom): the LICENCE box shows the Device ID (12 characters), and its GET PRO button opens the order form with it already filled in. Nothing is shipped.
   ENTERPRISE & COMPLIANCE (121.30 EUR incl. VAT): everything of PRO plus the printable test reports (PDF) and final report of the test suite for inspectors and service technicians, the equipment register, users with login and activity log, report extras and exports in your format. PRO owners upgrade for 74.80 EUR - never more than 121.30 EUR in total.
5. Activate: you get a link and a QR code by email - open the link or scan the QR code in the app (see activate PRO). Done: PRO forever.

UPCOMING: a 3D-printable housing (free STL download) and a printed housing to order.

You are a maker, or the board is sold out? BUILD YOUR OWN from an ESP32-S3/C3 board and a 3.3 V RS-232 board - same firmware, same licence price.

What you need

A computer (Windows, macOS, Linux or a Chromebook) with Chrome, Edge or Opera - phones and tablets can not install firmware. A USB-C data cable: many cables that come with chargers only charge and carry no data. If the board is not found at all, try another cable first. No driver and no program to install: everything runs in the browser.

1. Plug in the board: connect the USB-C port of the board to your computer. The DB9 plug does not need to be connected to the scale for this.
2. Open the update page: up-scales.com/update/?scale=diy (the UP↑SCALE DIY firmware: it starts with the pins of this adapter, nothing to choose). The newest version is on top (marked as the latest one).
3. Click INSTALL at the newest version. The browser opens a window with the serial ports: choose the port of the board - it is the one that appears when you plug the board in (often called "USB JTAG/serial debug unit", on Windows a COM port, on macOS/Linux usbmodem/ttyACM). Click Connect.
4. No port to choose, or "failed to connect"? Put the board into download mode: hold the BOOT button, press and release the RESET button (RST), then release BOOT. Click INSTALL again and choose the port.
5. Erase: the installer asks whether to erase the device. On a new board you may tick it (there is nothing on it to keep). Click Next, then Install.
6. Wait until it says "Installation complete" (about 1 minute). Do not unplug the board while it installs.
7. Start the firmware: press RESET once (or unplug the USB-C cable and plug it in again). Close the installer window.
8. Open the app (up-scales.com/420, on any computer, phone or tablet with Chrome, Edge or Opera - on the iPhone with the Bluefy browser) and click CONNECT. Choose "UP↑SCALE (DIY) #...". The free version runs - now connect your scale.

It does not work?

No port in the list: another USB-C cable (a data cable), another USB port of the computer, then download mode (step 4). On Linux your user needs the right to use serial ports: sudo usermod -a -G dialout $USER, then log out and in again.

"Port is busy" / "failed to open": another program uses the port (our app in another tab, the Arduino IDE, a serial monitor): close it and try again.

The app does not find the adapter after the install: press RESET once more (or plug it in again), and wait 5 seconds. Bluetooth must be switched on in the settings of your phone or computer.

1. Find your Device ID: in the app, with the adapter connected, tap ⭐ FREE VERSION - UPGRADE TO PRO below the title (or SCALE ✰ INFO at the bottom). The LICENCE box shows Device ID: ... (12 characters).
2. Order: tap GET PRO there - the order form opens with your Device ID already filled in. Or open the order form and type it in.
3. Pay: you get the payment details by email. Right after the payment you get your licence by email: a link and a QR code.
4. Activate: connect the adapter in the app. Then open the link on the same phone/computer - or tap 📷 SCAN LICENCE in the LICENCE box and scan the QR code (or PASTE KEY and paste the key from the email). The app sends the key to the adapter, which checks it and switches to PRO. Done: PRO forever on this board, on every phone and computer that connects.

Lost the email, or the board was erased? The app remembers the key and sends it again by itself. A phone or computer that does not know the key yet asks you when the board was PRO before and is free now (erased) whether to look it up on up-scales.com (or tap 🔎 FIND MY LICENCE ONLINE in the LICENCE box) - only with your OK, and only the Device ID is sent. The app never contacts our server for this by itself. Without internet: the lost licence page shows it again on any device.

New firmware versions are free. The app tells you when there is one ("UPDATE YOUR SCALE"), and the update page lists all versions with what changed.

1. Close the app (or disconnect the adapter in it), and connect the board by USB-C to your computer.
2. Open the update page (UP↑SCALE DIY), click INSTALL at the newest version and choose the port of the board (download mode is usually not needed for updates).
3. Erase: do NOT tick it for an update - an erase deletes everything on the board: your RS-232 settings, THINGS and recipes. (Your PRO licence comes back by itself: the app sends it again when it connects, or - if it does not know it yet - offers to look it up online - or use the lost licence page.)
4. Wait for "Installation complete", press RESET (or plug it in again), connect it in the app - done.

Please also keep the app up to date: the app shows when a new version is ready - one click on its message installs it.

1. The adapter has a DB9 male plug, wired like the port of a PC (pin 2 RX, pin 3 TX, pin 5 GND, RTS on pin 7 is switched on). Plug it in where the PC cable of your scale would go - with the scale's own RS-232/PC cable or a gender changer.
2. Power: the adapter needs USB-C (a USB charger or a power bank) - it gets no power from the scale.
3. In the app: RS-232 settings → choose the maker of your scale (METTLER TOLEDO, KERN, OHAUS, A&D, ADAM, SARTORIUS) or press 🔍 AUTO-DETECT, set the capacity and the decimals. On a verified scale also switch on LISTEN ONLY and EXACT WEIGHT.
4. Check: the weight in the app follows the display of your scale.

No weight in the app?

"No signal at all" (shown by the auto-detect): switch on the interface of your scale in its menu (many scales need "continuous output", some send only with the print key). If it is on, the wires are crossed the wrong way for your scale: use a null-modem adapter - or a straight cable instead of a null-modem cable. (The direction of the wires is fixed in the RS-232 chip of the board, so it can not be switched in the firmware.)

"Data, but unreadable": choose the preset of your scale, or set baud rate, data bits and parity by hand (see the manual of your scale).

Wrong values: check the preset, the decimals and the capacity in the RS-232 settings.

A fraction of the usual price

The interfaces scale makers sell (USB, network, wireless) often cost 150-440 EUR - and come without any software: you still need a PC and a program for hundreds of euros, or a monthly subscription. Here the app is included: weighing, counting, check-weighing with statistics and ℮ lot checks, recipes, labels with barcodes, sales log and inventory - on your phone, tablet or laptop. See the costs over five years.

Try everything first

With other solutions you pay before you know whether they work with your scale. Here the board is the only risk: install the free firmware, connect your scale, and try every PRO mode with your own products. Buy PRO only when you need it every day.

Test your scale yourself

With the adapter on your scale (also a verified one) the SCALE SELF-CHECK of the app runs the tests of the official procedures (OIML R 76-1 Annex A, EURAMET cg-18) on it: repeatability, corner load, accuracy & linearity, tare, zero-setting, discrimination, creep and zero return, warm-up, stable equilibrium. A checklist shows what is done and which test is asked for a verification, an inspection in use or a calibration; the results are judged against the permitted errors of the accuracy classes that fit your scale. You get a report to print or save as PDF, and for inspectors and service technicians a final report with their name, signature and stamp fields on certificate-style pages. Not only for officials: a failed verification appointment costs the call-out and the re-verification, so test first, fix the obvious and call only when the scale is ready - and a used or new scale you are about to buy or accept can be checked on the spot, before the money is gone. It is a test record and no verification: the display of the verified scale stays the legal reading, and whether a record is accepted is the decision of the authority.

Several scales, several devices

Use several scales in one program (kilos of flour on the platform scale, grams of salt on the fine scale) and control one scale from several phones and computers at the same time - they all see the same data.

Your data stays yours

Products, recipes, stock and sales are saved on the adapter itself. No account, no cloud, no tracking, no advertising - the app also runs as a single offline file.

PRO LICENCE 46.50 EUR
ENTERPRISE & COMPLIANCE 121.30 EUR
INCL. VAT - ONCE - FOREVER