XmcHotWire

Story

Do you remember the classic game hot-wire, when it is not allowed to touch the wire during following its curve? The new and advanced version automatically measures the needed time from the start to the end and displays it on a 3 digit 7-segment display. Fails or success is indicated by a piezo buzzer. The kit is powered by two Mignon batteries what makes it portable and playable everywhere.

Electronics

The electronic system is based on a XMC2GO evaluation kit from Infineon.

The whole system is battery powered by two 1.5V Mignon batteries.

The XMC2GO microcontroller evaluation kit offers 14 I/Os, respectively 11 in/outputs and 3 inputs only - exactly what is needed for this application:

Pin 1   P2.7(I)  Wire-Start        Pin 16   P2.6(I)  Hot-Wire
Pin 2   P2.9(I)  Wire-End          Pin 15   P2.0(O)  Seg D
Pin 3   P2.10(O) Buzzer            Pin 14   P0.15(O) Seg C
Pin 4   P2.11(O) Seg 3             Pin 13   P0.14(O) Seg G
Pin 5   GND      Ground            Pin 12   P0.9(O)  Seg E
Pin 6   3V3      Power             Pin 11   P0.8(O)  Seg A
Pin 7   P0.0(O)  Seg 2             Pin 10   P0.7(O)  Seg F
Pin 8   P0.5(O)  Seg 1             Pin 9    P0.6(O)  Seg B

Mechanics

The assembled PCB provides two socket-terminals where a 2mm brass wire can be entered. It is up to the user to bend and curve the hot-wire at least that its start and end by its distance fits into both socket-terminals.

A 3mm screw terminal including a soldering eyelet is used for connecting the probe via a approx. 40cm long flexible cable.

Software

By the provided application software, the microcontroller has basically four tasks:

• Observing whether the hot-wire is touched by the probe
• Taking the time from start of hot-wire until its end
• Multiplexed-driving a 3-digit 7-segment display to show the time
• Output a sound signal when failed or completed successfully

The software is developed by ModusToolbox(TM) - a free of charge IDE from Infineon. The source code of the XmcHotWire-project is attached and can be modified by yourself.

Play Instruction & Demonstration

After switching on the system by switch SW1 you have to touch first the START-pad by the probe. This will reset and start the time measurement.

Go along the hot-wire without touching it with the probe.

In case you touch it, a tone will indication is given as well two red-LEDs on the XMC2GO will flash. This means you failed and you have to return and touch to the START-pad in order to begin a new trial.

If you touch the END-pad by the probe (without having any fail in between), then a sound signal is generated and the measured duration time is displayed steadily.

In order to start a new trial just return to the START-pad and touch it. The time counts from now on... for your next trial!

Summary

XmcHotWire is the advanced electronic version of the classic HotWire game. Getting the time measured now automatically will encourage young and old people. Forever young!

Have fun & Stay safe!

Holger

P.S.: This project was used in November 2023 during our company's KidsDay... and children above 10 years soldered and built it by themselves - and passed the Hot-Wire - faster than me ;-)