JawnCon0x3 Badge: User Manual

Overview

This badge is a 4-digit calculator with a built-in touch-tone (DTMF) generator, a handful of hidden games, a serial menu for customizing it, and a wired link for connecting to other badges. Some of what it can do isn’t listed here. Poke around.

Display: 4-digit, 7-segment Keypad: 16 keys: digits 0-9, operators + - * /, decimal point ., and =

Powering On

On boot, each digit flickers through random static, then locks into place one at a time, left to right, spelling out the badge’s boot text. The animation takes about 3 seconds. The factory boot text is JAWN, but you can change it to anything you like (see The Serial Menu).

If the display shows a fixed row of dashes at boot and the keys do nothing, the badge couldn’t find its keypad. That’s a hardware fault, not something the keypad can fix.

Calculator

• Decimals: results show as many decimal places as fit after the whole-number part. With only four digits, precision is limited: 1234.5 won’t fit, and tiny fractions round off.
• Negatives: the minus sign takes up one digit position, so negative results can have up to 3 digits (-999 at most). Positive results go up to 9999.
• Errors: a result that is too big for the display, or any divide by zero, shows EEEE. Double-press = to clear it.

Example: 1 2 + 8 = shows 20.

Tones

Every key makes a sound, just like a real touch-tone phone:

• Digits 0-9: standard DTMF tone pairs
• =: a single 2600 Hz tone
• .: a dual-tone burst at 1700 Hz and 2200 Hz

The tones play in every mode, including inside the games.

Secret Games

Type a four-digit code and press =, and the display flashes GAME before the game starts. Each game returns you to the calculator when it ends.

These codes are checked only when you press = right after typing them. If you ever need one of those exact numbers in a real calculation (for example 10 + 1337 =), the game will launch instead of the answer.

Higher or Lower

The badge picks a secret number from 0 to 9999.

1. Type a guess (up to 4 digits) and press =.
2. HI means the answer is higher than your guess. LO means it’s lower.
3. Keep going until you land on it. There’s no limit on guesses or time.
4. A correct guess shows WIN, then the number of guesses it took.

DTMF Tone Recall

A memory game played by ear.

1. The display shows the round number, then the badge plays that many tones with the display blank.
2. Repeat the sequence on the keypad. Each key you press plays its own tone back, and no = is needed.
3. Get it all right and the sequence grows by one tone and replays from the start.
4. A wrong digit ends the game: END, then your score, which is the longest sequence you fully recalled.

Hex Recall

A speed round: 5 rounds, 5 seconds each.

1. The display shows a random number in hexadecimal (0-9 and A-F).
2. Work out the decimal value, type it, and press = before time runs out. The keypad has no letter keys, so you always answer in plain decimal.
3. After each round the correct decimal value flashes, whether you were right, wrong, or too slow.
4. After round 5 you see your score as x-5. For example, 3-5 means 3 correct out of 5.

An unanswered round counts as wrong.

Something Else

There is at least one more game on this badge, and it doesn’t appear in the list above. The high-score screen (see below) hints at it. Finding the way in is part of the fun, and you may need a friend.

The Serial Menu

The badge has a settings menu you reach from a computer.

Connecting: use a USB-serial connection at 115200 baud, with a terminal that sends a newline when you press Enter.

Opening it: type M and press Enter at any time. The display shows WAIT the whole time the menu is open. The badge is paused while you’re in it, so calculator and game activity stops until you leave.

==== Badge Menu ====
1) Set boot text
2) View high scores
3) Badge-to-badge link
0) Exit menu

1) Set Boot Text

Choose any 4 characters from 0-9 and A-Z (lowercase is converted to uppercase). Anything else is rejected and nothing changes. The new text is stored permanently and appears the next time the badge powers on.

Not every letter looks great on seven segments. M, K, W, X, V and a few others are approximations, so try a few and see what you like.

2) View High Scores

Your best results in each game are saved and survive power-off:

• Higher or Lower: fewest guesses
• DTMF Tone Recall: longest sequence recalled
• Hex Recall: best score out of 5

One more line on the list shows LOCKED. Make of that what you will.

3) Badge-to-Badge Link

This connects your badge to another one. See the next section.

Linking Two Badges

1. On both badges, open the serial menu and choose 3. (Each badge needs its own computer, or take turns: the link waits 15 seconds, so start the second one quickly.)
2. Connect the badges’ link pins with a short cable.
3. Each badge shows WAIT while it listens. When the handshake succeeds, each badge shows the other badge’s boot text for about 2 seconds, and the serial console reports who you linked with.
4. If nothing is found within 15 seconds, the attempt times out and nothing changes.

Each badge keeps a running count of how many successful links it has made, stored permanently, and it is shown at the top of the link screen. Because a badge introduces itself by its boot text, the name you set in the menu is your badge’s identity.

Something may change after your first successful link. Keep your eyes open.

Wiring (for builders)

The link runs at 9600 baud on its own pins, separate from the USB serial connection, so you can keep your computer connected while linking. The connector style (header, 3.5mm jack, pogo pins) is up to you. All that matters is that TX and RX are crossed and the grounds are shared.

Quick Reference

Happy hunting.

Assembally

Build it

Using the listed bill of materials above, go to the JawnCon soldering station; you will find the JawnCon Parts drawers th ere. You’re welcome to solder this as you seem fit, but I recommend the following order: Resistors, Diodes, ICs, the Crys tal, Capacitors, Buttons, and then the LED display. You can then plug it into the provided test cable at the soldering st ation to make sure it works! If not, there are multimeters, oscilloscopes, and other tools available to help troubleshoot . Once you see that it works, you can then install the power pack.

Enjoy the badge!