As of December 25, 2023, I have updated the second-generation portable beacon light and changed and optimized the 3D model in the project and attachments.

I have created a QQ electronic communication group. All enthusiasts are welcome to join the group chat: 527972069.

1.Project Introduction

At the beginning of this year, a light-emitting prop in the game "OUTER WILDS" caught my attention and inspired me to bring it from the virtual world to real life. To do this, I spent a lot of time designing circuits and models and went through many iterations. Now, I've finally managed to create a handheld lamp that I'm happy with.

2.Work Function and Design Plan

This work uses a 12V lithium battery pack to provide power for the linear regulator and LED light strip. The linear regulator reduces the 12V voltage to 3.3V to power the control module. The control module integrates single-channel touch stepless dimming, 433MHz wireless reception and decoding functions, making the work equipped with remote control and touch dimming features. In addition, the circuit board is also equipped with a three-cell lithium-ion charging management module in series, which can charge a 12V lithium battery pack. This work is not only highly ornamental, but also has practical functions and can be used as table decorations and outdoor lighting. In addition, a lithium battery charging management module is integrated inside the circuit board, and the battery can be charged using a Type-C charging cable.

The following is a simple structural block diagram of the circuit design of this work:

3. Preparation of consumables:

Listed here are some of the spare parts used to assemble this piece.

Light strip: Use LED light strip with color temperature 6000K and voltage 12V. The back is self-adhesive and the light strip can be cut freely.

Antenna: Both the transmitting and receiving antennas use 433MHz spring antennas.

Charging female base: Use Type-C 2PIN horizontal female base.

Heat sink: Use 9*9*5 aluminum heat sink. It is recommended to choose one with adhesive backing.

Magnet: Use 17mm*15mm*6mm (L*D*H) rubidium magnet.

Copper foil tape: The copper foil tape acts as a touch sensing electrode. Cut out a piece of 20mm*30mm copper foil tape, connect the copper foil to the TCH circuit with solder, and stick it on the back of the sensing surface.

Black textured paper: used for internal shading. The gray casing is somewhat light-transmissive. Use black textured paper to stick to the inside of the casing to reduce light transmission.

Lithium battery protection board: Use three series lithium battery protection boards, which can provide balanced charging, undervoltage, overvoltage, and overcurrent protection.

Metal self-locking switch: Use 12mm metal self-locking switch. Used to control the overall circuit.

4.Hardware Introduction:

Battery charge management:

This work uses IP2325-3S chip for battery charging management. This chip is a synchronous switching boost charging management chip for three-cell lithium batteries connected in series. It can charge three-cell lithium battery packs connected in series after being connected to a 5V power supply.

IP2325-3S has rich protection functions to ensure that the module works stably and reliably. The chip integrates the NTC temperature control function, which can detect the battery temperature through the resistor connected to the 4th pin (NTC). When the battery temperature is too high or too low, the charge management chip will stop charging the lithium battery pack.

Please note that the charging management chip will generate heat during the charging process. It is recommended to use a 9*9 (mm) heat sink on the top of the chip to obtain good heat dissipation effect. When using a heat sink, please ensure that the height of the surrounding components does not exceed the charging management chip, and avoid short circuiting the surrounding components due to the heat sink.

Single channel touch stepless dimming:

This work uses a single-channel touch chip RH6618A to achieve stepless dimming. The chip's stepless dimming PWM frequency is as high as 25KHz, making the dimming process smoother. RH6618A has a built-in capacitive touch sensing circuit, which can realize touch dimming by touching the TCH pin.

During operation, the POUT pin outputs a PWM signal, which is connected to the gate of the NMOS tube to drive a larger power light strip. It is worth mentioning that this chip does not require a programming program and has built-in mode configuration pins: MOD1 and MOD2. By changing the levels of these two pins, the stepless dimming working mode can be switched. When configuring the high level, connect the mode configuration pin to VDD or directly leave the pin floating; when configuring the low level, connect the pin to ground.

The 5th pin (TCH) of RH6618A is the touch sensing pin. Touch sensing can be achieved by connecting a resistor in series and connecting the copper foil. Attach copper foil to a non-metallic sheet, and the light can be dimmed by touching the sheet. If high and low level control dimming is used, a signal line with a diode and resistor in series can be connected next to the copper foil. When a high level is input to the stepless dimming chip, dimming or switching can be realized; when a low level is input, dimming is stopped.

It should be noted that other circuit layouts should be reduced near the TCH pin to improve the anti-interference of touch dimming.

Wireless remote control circuit:

As a common wireless remote control solution, the 433 remote control circuit achieves information transmission by transmitting and receiving electromagnetic waves with a frequency of 433MHz. In this work, I used an integrated coding and transmitting chip (LBT12B), a receiving chip (LR680J) and a decoding chip (FJ1527-M3) to achieve a complete wireless remote control function. These chips have the characteristics of low cost, simple peripheral circuits, and low power consumption. The 433 transmitter module only needs a 3V button battery to drive.

In the wireless remote control module, the input electrical signal goes through processes such as encoding-transmitting-receiving-decoding and outputting electrical signals to achieve remote control. The decoding chip (FJ1527-M3) is equipped with a multiplex switch. When the switch is pressed twice in a row within 1 second, the module will enter the code matching mode. In this mode, a new remote control control circuit is supported. In pairing mode, just press the transmit button on the remote control once to complete pairing. If you press and hold the switch for more than 8 seconds, the decoding chip will clear the pairing record so that the previously paired remote control will no longer be recognized. If you need to re-identify, you need to pair again.

In order to improve the remote control distance of the 433 remote control module, please be careful not to lay copper around the transmitting and receiving antennas (ANT).

Linear regulator:

Since the work uses a 12V lithium battery pack for power supply, and the rated voltage of some control chips is low, the 12V voltage needs to be reduced to 3.3V to power the control chip. Here, I used a stable linear voltage regulator - ME6118A to convert the 12V power supply to a voltage where the chip can operate safely and properly.

Three series lithium battery pack:

The lithium battery pack is self-made by me and has a built-in charging protection module. For details, please check out my other open source project: FM3450C three-cell lithium battery charging protection chip in series.

The second-generation lithium battery pack uses 18650 lithium batteries, lithium battery charge equalization protection plates, battery compartments and 3D printed parts, and can be assembled through simple welding.

Circuit diagram drawing:

I used JLC EDA to design the schematic diagram and PCB diagram. These two pictures are relatively simple and very suitable for novice DIY attempts. In the schematic diagram, I marked some capacitors that need to be paid attention to withstand voltage. The capacitance values ​​of these capacitors are marked with "*" after them. It is recommended to use capacitors with a withstand voltage of 16V or above to ensure the stability of the circuit.

The following is a physical picture of the board:

5.3D Model Design:

Autodesk Fusion 360 is a modeling software that is very suitable for novices, and this model was also designed using it.

After the design is completed, an FDM printer is used to print out the 3D physical drawing.

6. Production process:

Light board: Cut the LED light strip to a suitable length, stick it on the bottom board, then connect it in parallel with wires, and finally fix it with hot melt glue.

The bottom plate can be used in the attached 3D model. Or buy 2 plastic plates of 140mm*140mm*2mm and drill the holes yourself.

Fix the handle, copper foil tape, circuit board, rubidium magnet, and copper pillar on the model.

Cover the inside of the model with black masking tape, install the lampshade (it needs to be fixed with glue, you can use T9000 glue to fix it, the lampshade can be installed at the end) and put hot melt glue on the screw of the switch to prevent it from loosening.

Install the light panel and battery and the spacers and studs. Then connect the lines. (At this stage, you can start the module to test whether the circuit can operate normally.)

Cover the other light panel and secure it with studs.

Cover the lampshade fixing and install the screws. Install the lampshade after applying glue to the lampshade fasteners.

It is ready to use after it solidifies.

The following is a display of the finished product:     

7. Conclusion:

This lantern is not only a realistic representation of the spirit of gaming, it is also my tribute to the creativity of gaming. My goal is to let more people feel the unique charm and inspiration of the game through this work. You can scan the QR code at the beginning of the article to watch the demonstration video of the portable lamp. This work project has been released to the OSHWHub. I will continue to update and improve the content of the project. Interested friends can search for me by entering the article name on Bilibili or click the following link to find the video of the work: [OSHWHub] I recreated the beacon light in the interstellar pioneer.

Finally, I sincerely thank OSHWHub Platform for providing me with free consumable support, which gives me more opportunities to verify the solution. Thank you all for your attention and love!