Coin validators used in Millennium payphones were made by Landis & Gyr, and they are advanced devices capable of programming a variety of coins to be detected (typically up to 18). There are five sensors that detect different physical parameters, which are tested against predefined values and their ranges. The validator then passes the coin number to the payphone's main board, but the monetary value of each coin is defined in one of the MM tables. A typical setup (USA/Canada) is listed below. Some coins may exist in the coin validator, some not - depending on the market (US/CAN) and whether they were updated to the latest coins (Canada had a couple of updates through the years).
1 CDN Nickel
2 CDN Nickel 2
3 CDN Dime
4 CDN Quarter
5 CDN Dollar
6 US Nickel
7 US Dime
8 US Quarter
9 US Dollar
10 CDN Steel Nickel
11 CDN Steel Dime
12 CDN Steel Quarter
14 New CDN Dollar

Coin validator was to a great extent reverse-engineered (https://wiki.muc.ccc.de/millennium:coinvalidator) but there is no software available to the public to recalibrate it. I made an attempt to create it and it is now available to download.

Recalibration may be needed for a variety of reasons:

• Swapped control board from another unit
• Some coins not defined (new Canadian coins, a dollar coin, etc.)
• Calibrating completely different coins for hobby purposes
• Broken EEPROM contents

Features:

• Backup, restore and display EEPROM contents
• Display coin definitions
• Enable / disable coins
• Calibrate new / existing coins

Requirements:

• Windows (64-bit), program runs in the text terminal
• USB to RS-232/TTL interface. It must be TTL (so voltage levels 0-5V, while RS-232 typically operates on +/-12V). Typically those have a USB plug on one side and four wires the other side - Ground, +5V, TX, RX.
• 12V power supply
• Connect everything according to schematics - see link above.

How it works: Connect everything, start the program. Enter the COM port number and press enter. It tries to read validator's EEPROM (256 bytes accessible to user). Menu will show


Everything is kinda self explanatory, but let's see option 4. We can see all coin definitions, this is EEPROM ID 20 (typical validator for the US phones, eg. used by FSH/Wimactel). Option ID 40 or 60 has more coins defined (for Canada):


Now we're trying to learn a new coin. Get at least 3 coins ready and put them in 10 times at minimum, then press any key, or continue throwing coins until it counts 20. Mean values + ranges will be calculated. For the range, we use 6 standard deviations, if those seem too high, we switch to 3 std. dev.


Don't forget to run a backup and use at your own responsibility!.

All new calibration if the coin validator is completely messed up: restore backup from a similar validator. Mind that calibrations are individual, so it might not be optimal. Now run the calibrations for each coin and save them.

Another way to use the tool: backup, use your favorite hex editor, then restore from modified file.

Latest release: tcoinval_2025-01-25.zip