I offer firmware for RFID Domination Timer project that is based on AVR ATmega328P chip (Arduino) architecture. In price is included machine code .hex for that architecture for your RFID cards that you have provided via Google Spreadsheet teamplate. Also there is included .lppz archive for PCB manufacturing with drilling, layers inforamtions etc. I don't offer source code in .ino format or hardware with PCB.

Project description:
Domination timer (DOMINATOR) is a stopwatch device designed for 2 teams (scalable up to 4 teams) that play against each other and try to occupy the point and keep it for as long as possible. The stopwatch is suitable for Airsoft / Paintball game mode DOMINATION, resp. Capture Hill. They consist of an ATmega328P microcontroller (AVR), which can be part of the Arduino development kit (Uno / Nano / Pro Mini). An LCD character display (size 16x2 or 20x4) is used to visualize the times. The times are listed in two lines below each other and are dynamically updated if there is an active team at the point (a point occupied by a team). The stopwatch is equipped with indicator LEDs in team colors, which signal the active team at the point and a detector (piezo transducer), which announces the change at the point after attaching the RFID card.

Teams are implemented in the game - RED team and GRE team who play against each other and try to occupy the point and then keep it for as long as possible. At the beginning of the game, the display shows the times 00 hours, 00 minutes, 00 seconds for RED team , GRE team . Each team member is equipped with an RFID chip that is integrated into the bracelet (or card / keychain). The RFID chip transmits its unique identifier - UID (unique ID), which is read by an RFID reader and verified in the logic of the system to which the entity (team) belongs. Individual bracelets can be color-coded (red, green by team and entity function), which allows them to be distributed more quickly to players, but also archived and stored by color. The RED team will occupy the point when the RED team member attaches his card to the RFID reader. This action triggers a buzzer that announces the change of point with a short beep. Subsequently, the LED of the RED team at this station will light up and the display will start adding the time for this team until the member's team card is inserted, Referee , or Eraser.

If the point is occupied by a GRE player and the card is attached to an RFID reader, the buzzer will announce this change with a short beep, the GRE LED will light up (RED LED turns off), RED's current time stops , and GRE's time is scored. If the Referee attaches his RFID card, the running time will stop at the current value. The point becomes neutral, the active team's LED goes out. The stoppage lasts until a member of the RED team or the GRE team presents their card. This type of card is thus suitable for temporarily stopping an ongoing game, controlling a player's intervention, or injuries. At the same time, the card can be used at the end of a round of the game, to evaluate the round, respawn teams before continuing. If Eraser attaches the card, both times will stop and reset to the initial value of 00 hours, 00 minutes, 00 seconds, which will be displayed. The Eraser card is used to restart the game, to initialize a new game without the need for a power-on cycle. The RFID reader responds to the insertion of an RFID card immediately, including the entire logic of the Dominator project. The project is suitable for Airsoft events, sports facilities, or Airsoft teams, which can build a Dominator device with their own hardware.

Firmware is universal for Arduino Nano / Uno or standalone ATmega328P chip, it is also possible to use the available PCB design for the production of printed circuit boards (PCB using Arduino Nano only!). The advantage of the RFID Domination timer project is that the usage license authorizes the user to clone and create X points with the same configuration via machine code. Machine code (.hex) is a compiled firmware format for the RFID Dominator project for supplied UID RFID cards that are embedded in the code before compilation. It is thus possible to place any number of independently operating RFID Domination timer points in the game, which respond to identical RFID cards according to a uniform configuration. The RFID Dominator system is programmed well, it exist from 2018 year, it can be put into the game immediately. Firmware uploads within 10 seconds via XLoader (recommended software).

How RFID Domination Timer works (hardware side):
NXP RC522 RFID reader communicates with the microcontroller (Arduino / stand-alone chip ATmega328P) via the SPI bus with a clock signal (SCLK) of 4 MHz. The RC522 reader responds to the RFID chip at a distance of approximately 3 cm from the antenna, while having a configurable antenna gain in the range of 18 to 48 dB (48 dB is used in the final application for DOMINATOR). Reads the UID (identifier) of RFID chips in range, forwards this identifier to Arduino. Arduino compares the read address of the card in a multi-condition, triggers a buzzer beep, applies digital states to the LEDs, runs a universal counter controlled by the internal function millis(), which is responsible for counting both times.

Based on the fulfilled condition, the counter starts to be applied to the given team to which the UID belongs and the time counter is running. The time is plotted on a 16x2 or 20x4 LCD character display. The time data is sent via the I2C bus with a clock signal (SCL) of 100 kHz (Standard Speed). To restore the display as quickly as possible, only the number at the given position (given character) is overwritten. Hours and minutes and seconds are overwritten only when changing and always only for a given team. In case of serious interest, it is possible to create firmware in machine code for Domination Timer to 3 or 4 teams, also possible to use Fast Speed I2C up to 400 kHz (based on deal).

Actual version of RFID Domination Timer project supports these types of firmware RFID readers NXP RC522:

• Firmware version: 0x12 = counterfeit chip - (non - original NXP chip, replacement)
• Firmware version: 0x91 = Version 1.0 - (original NXP chip)
• Firmware version: 0x92 = Version 2.0 - (original NXP chip)

Where RFID Domination Timer should be used:
RFID Domination Timer project is, in terms of its versatility, suitable for implementation in Airsoft actions, and with the possibility of cloning the firmware, it is possible to place X Domination Timer points in the game field with identical firmware, which players can play with the same RFID cards. Domination Timer is also suitable for teams, sports grounds and playgrounds, which can use this device to expand the services and game modes offered for different numbers of players. If RFID cards, bracelets or key fobs are color-coded, it is very easy and universally distributed to players based on their team. Their archiving is also simple. Using cards, bracelets or key rings is easy and can handle all ages in Airsoft games. RFID chip itself is protected in a plastic case, it does not mind mud, dirt, water, frost, it is fully maintenance-free. It has no battery, the chip activates the RFID reader, which charges it with the transmitted electromagnetic field and allows it to send a UID - identifier if it is within range of the RFID reader. Domination Timer is suitable for game modes with the same number of players in both teams, e.g. DOMINATION, Capture Point (Points for multiple cloned Domination Timer points).

Project hardware - RFID Domination Timer:

• Arduino UNO / Nano / standalone chip ATmega328P
• LCD 20x4 or 16x2 (20x4 layout is used in PCB design)
• I2C module for LCD display
• RFID reader RC522 (13.56MHz)
• ISO / IEC 14443-A standard keychains / cards / bracelets
• Passive buzzer (optional)
• 2x LEDs, 2x resistor (1x 220 ohm for GREEN LED, and 1x 1 kohm for RED LED)
• 2x resistor 10K I2C pullup (optional, useable for larger distance between display and Arduino)

Software is delivered in machine code (.hex) at your mail for the ATmega328P architecture. The price is for 10x RFID UID for each team and 2x for the Referee and Eraser, total of 24x UID. If you want to increase the number, it is possible for 5 GBP / another 5 UID. The machine code cannot be modified and is tailor-made for the authorized operator based on the UID, which it delivers in .xls format (the template is available on the project page with an extended project description). It is possible to try for free one UID for each entity in project (ping me at mail for that).

More about project you can read at: https://martinius96.github.io/Airsoft-DOMINATOR-RFID/en/index.html

Template (.xls) document where RFID UIDs can be written for each entities from test sketch available on website: 
https://docs.google.com/spreadsheets/d/1EHpdJi8v84eJ-6ExEPT6JuPkxI9Tfbm8v85zGRFvJ1Q/edit?usp=sharing

Shareware version of project
Project can be tested for free with your hardware before buy or payment in shareware version. There is available firmware on project's website. Firmware let you to use any 4 RFID cards (each for one entity). So you will have chance to test whole compatibility of project with your hardware. You can measure time up to 15 seconds for each team (then time will be automatically stopped). Then you can reset time using Eraser card and you can measure again 15 seconds for each team. Full version of project is without time limitation and with max 24 UIDs that are written directly to PROGMEM of microcontroller.

Firmware (.hex file) can be uploaded to microcontroller via Xloader: https://www.hobbytronics.co.uk/arduino-xloader
Or more experienced users can use AVRDUDE via console. For Arduino boards use 115200 baud/s upload speed. For Arduino Nano V3.0 clone use 57600 baud/s (Old Bootloader), otherwise firmware will be not uploaded.

Shareware firmware for direct download:

• Shareware_RFID_DOMINATOR.hex - compatible for standalone ATmega328P chip with 16 MHz oscillator, Arduino Uno / Arduino Nano / Arduino Pro Mini