Summary of Build your own Wireless Network detector using PIC12F629
This project is a wearable, passive wireless hotspot detector that translates detected Wi‑Fi signal strength into tactile pulse patterns via a vibration motor. A microcontroller controls and reads an off‑the‑shelf D‑Link keychain Wi‑Fi detector by pressing its button, interpreting its indicator LEDs, and converting their state into heartbeat‑like vibration rates to convey presence and relative signal strength. It does not transmit any signals and only senses. Building it requires microcontroller programming and may need interface/adaptation if a different sensor is used.
Parts used in the Wireless Network detector:
- Microcontroller (PIC12F629 or similar)
- Off‑the‑shelf Wi‑Fi detector (D‑Link keychain sensor used)
- Vibration motor (vibe motor)
- Custom interface electronics (to press sensor button and read LEDs)
- Power source/battery (for the microcontroller and motor)
- Enclosure/pendant or housing for wearable use
What This Is
This project is for a small electronic unit that allows the user to sense the presence and relative signal strength of wireless hotspots. It can be worn as a pendant or carried in a pocket. It is “always on” and communicates the presence and signal strength of an in-range hotspot by way of sequences of pulses – like a heartbeat you can feel. The stronger and faster the “heartbeat”, the stronger the wireless signal detected.
It does not actually authenticate or otherwise interact with a hotspot in any way. It is a 100% passive device, meaning it transmits nothing — it can detect hotspots, but cannot be detected itself.
How It Was Made
This project consists of a microcontroller, some custom interface electronics, a small vibe motor, and an off-the-shelf Wi-Fi detector – the one I used is by D-Link and is keychain-sized.
Here is the sensor I used, and some pictures of the construction. Details of the design will follow.
How It Works
The microcontroller periodically “presses” the button on the detector to initiate a reading. Then the microcontroller “reads” the output from the indicator LEDs on the detector, and uses this as the basis for pulsing out a signal on the vibe motor, which the wearer can feel.
In this way, the unit keeps you updated on the presence and signal strength of a wireless hotspot in your vicinity. No pulses means no signal. Short pulses means a weak signal. Faster, more frequent pulses means a stronger signal. This feedback is very much like a heartbeat, and is extremely intuitive to interpret.
How To Make Your Own
First of all, I use a microcontroller in this project. If you aren’t familiar with terms like 12F629 or .HEX files and how to blast them into a PIC, you will have trouble with this project.
The D-Link sensor I used works like this — press the button and the LEDs light up in a “scanning” pattern while it looks for a signal. It can be in this scanning pattern for up to a few seconds. Afterwards, it lights up either one, two, three, or four of the green LEDs to indicate relative signal strength. If there is no signal detected, a single red LED is lit. The LED(s) remain lit for a few seconds, then the sensor shuts off.
If your chosen sensor works differently, you will need to adjust the electronic interface and the program in the microcontroller accordingly.
For more detail: Build your own Wireless Network detector using PIC12F629
- What does this project do?
It senses nearby wireless hotspots and conveys presence and relative signal strength as tactile pulses via a vibration motor. - Does the device transmit any signals?
No, it is 100% passive and transmits nothing. - How does the project detect signal strength?
The microcontroller presses the detector button to start a scan, reads the detector's indicator LEDs, and maps LED states to vibration pulse patterns. - What does the vibration pattern indicate?
No pulses mean no signal, short pulses mean weak signal, and faster, more frequent pulses mean stronger signal. - What sensor was used in the build?
A D‑Link keychain Wi‑Fi detector was used in the project. - Can I use a different sensor?
Yes, but you will need to adjust the interface electronics and microcontroller program if the sensor works differently. - What skills are needed to build this?
Familiarity with microcontrollers (for example PIC12F629), programming .HEX files, and flashing the PIC are required. - How does the microcontroller interact with the detector?
The microcontroller physically presses the detector button to initiate readings and monitors the detector's LEDs to determine signal strength.
