A FIND MY RESEARCH CONCEPT / NOT A FINISHED PHONE
When a phone walks by,
your signal rides along.
GHOST imagines a tiny-message device using Bluetooth Low Energy broadcasts. A passing iPhone may carry its signal onto the internet. The receiving person needs a separate companion app—not Messages.
The path, in four beats.
The BLE board sends tiny encoded packets. The touchscreen shown in 3D is a UI concept, not supplied by the research firmware.
Apple's Find My network may upload the broadcast. No pairing or access to the passerby's phone.
The uploaded signal becomes available to a compatible research receiver.
The friend retrieves and decodes it with an internet-connected computer/app. It is not a regular SMS.
What it can / can't do.
CAN / in theory
Broadcast small, encoded data from your own device with no cellular plan on the sending side.
Let nearby iPhones relay those broadcasts through the Find My crowd network.
Use a separate internet-connected companion app to read them.
CAN'T / do not assume
Not normal texting to any phone. No reply comes back to GHOST through this design.
No guaranteed delivery or instant chat: about 3 bytes/second at the transmitter in the Send My research demo; relay delays often 1–60 minutes.
No help in empty woods without passing iPhones. Experimental and subject to Apple changes or blocking.
Send My's published ESP32 firmware is a send-only modem, with a separate macOS receiver. Its example does not include this touchscreen, on-screen keyboard or enclosure. Getting the screen and touch to work together with Send My is custom coding work (the Feather’s built-in charger handles charging); this is an illustrated concept and the pictured UI is not working code.
Real parts + sizes.
Every part in the 3D model is a real, common hobby module at its published size. The shell is built around them: parts + 0.5 mm wiggle room + 2 mm walls (1.5 mm front lip).
For comparison, an iPhone 16 is about 71.6 × 147.6 × 7.8 mm, so GHOST is a bit narrower, a lot shorter, and about 2.4× as thick. The thickness is the screen module (6 mm with its board) stacked on the ESP32 board (7.2 mm), plus walls. The strips above and below the screen are the screen board’s pin rows (the board is 12 mm longer than the glass).
| Part | Maker | Size (mm) | Real product page |
|---|---|---|---|
| 3.5" TFT touch screen breakout, 320×480 | Adafruit #2050 | glass 85 × 56 × 4 · board 97 × 56 × 2 verified | adafruit.com/product/2050 ↗ |
| ESP32 Feather V2 (Bluetooth board, USB-C, built-in LiPo charger) | Adafruit #5400 | 52.3 × 22.8 × 7.2 verified | adafruit.com/product/5400 ↗ |
| LiPo battery 3.7 V 1200 mAh, JST-PH plug | Adafruit #258 | 62 × 34 × 5 verified | adafruit.com/product/258 ↗ |
| USB-C charging | built into #5400 | (no extra board) verified | adafruit.com/product/5400 ↗ |
| Mini slide switch, SPDT (power) | Adafruit #805 | ≈ 8.5 × 4 × 3.8 body approx | adafruit.com/product/805 ↗ |
| Case: 2 printed halves | you print it | 62.6 × 102 × 18.7 outside concept, not test-printed | designed here (case page) |
Ask a parent/adult before ordering anything, and get an adult to help with the battery. “Verified” = size copied from the maker’s product page. “Approx” = the page lists no size, so it’s a typical size for that switch style. Mounting holes, connector spots and exact board placement are approximate. Measure your own parts before printing anything. If you ever use a board without a charger, Adafruit’s Micro-Lipo USB-C charger (#4410) is 24.0 × 19.0 × 7.2 mm.
A satellite-capable BLE service such as Hubble Network is a different, optional design. It could cover places with nobody nearby and potentially bridge data to real SMS with a cloud gateway, compatible hardware and a paid plan. It is not installed here.
Wiring, pin to pin.
In the 3D model, open See-through or Exploded to watch these wires connect.
| SCREEN #2050 PIN | FEATHER V2 PIN | WIRE | JOB |
|---|---|---|---|
| Vin | 3V | red | power (screen takes 3–5 V) |
| GND | GND | black | ground |
| CLK | SCK | yellow | SPI clock |
| MOSI | MO | blue | data to screen |
| MISO | MI | green | data back (SD card, optional) |
| CS | D15 | orange | screen chip-select (any free pin) |
| D/C | D14 | white | data/command select (any free pin) |
| RST | A0 | purple | reset (optional) |
| Y+ | D32 | brown | touch (needs an analog pin) |
| X+ | D27 | pink | touch |
| Y- | A1 | gray | touch |
| X- | D33 | cyan | touch (needs an analog pin) |
| FROM | TO | NOTE | |
| Battery JST-PH plug (red/black) | Feather battery socket (BAT) | plugs in, no solder | |
| Switch middle leg | Feather EN | switch closed = board off | |
| Switch side leg | Feather GND | ||
Pin names are from Adafruit’s #2050 and ESP32 Feather V2 guides. CS, D/C, RST and the touch pins can move to other free pins (you set them in code). Solder the screen’s IM2 jumper closed so it runs in SPI mode. Wire colors are just a suggestion. Solder thin wires straight to the pins so they fit in the 1.5 mm gap (bulky jumper plugs need a thicker case). Get an adult to help with the battery and soldering.
Source + safety.
Research: Send My (ESP32 firmware + macOS receiver) and the project's technical write-up; OpenHaystack explains Find My-compatible research accessories. Use only your own device for experiments. Don't rely on this for emergencies. An adult should help with battery wiring; LiPo cells can be damaged or unsafe if wired or charged incorrectly.
GHOST / CONCEPT 01 — FOR LENS · CASE FILES →