This project turns the LilyGO TTGO T-Journal (ESP32 + OV2640 + OLED) into a standalone Wi-Fi camera.
It starts its own Wi-Fi hotspot (AP mode) and serves live MJPEG video directly to your phone or laptop via a browser — no apps required.
- 📷 Live MJPEG video streaming over Wi-Fi (AP mode, no router needed)
- 📶 Connect directly to ESP32 AP →
ESP32CAM-AP - 🌐 Browser-based UI (http://192.168.4.1) with start/stop stream and settings
- 📺 OLED display shows SSID and IP address
- ⚡ Runs from USB power or single-cell Li-ion (e.g., 21700 with PCM)
- 🔋 Runtime: ~14–18 h on a 4900 mAh Samsung 21700, >30 h with 2P pack
- LilyGO TTGO T-Journal (ESP32, OV2640 camera, 0.91" OLED, SMA antenna)
- Camera: OV2640 (supplied with board)
- Antenna: 2.4 GHz SMA (supplied with board)
- Power:
- Micro-USB (5 V from power bank or wall adapter), or
- Single-cell Li-ion/Li-Po (e.g., Samsung 21700 4900 mAh with PCM protection) on JST-PH 2.0 connector
- (Optional) MicroSD card for snapshots / logging
project/ ├─ platformio.ini ├─ src/ │ └─ main.cpp └─ README.md
platformio.ini: PlatformIO configurationsrc/main.cpp: Firmware codeREADME.md: This guide
- Install Visual Studio Code
- Install PlatformIO IDE extension
- Clone or copy this project folder
- Open the folder in VSCode (PlatformIO auto-detects
platformio.ini) - Connect TTGO T-Journal via micro-USB
- Build & Upload:
- Click ✔️ (Build) then → (Upload) in the PlatformIO toolbar
- Or use shortcuts:
Ctrl+Alt+B(build),Ctrl+Alt+U(upload)
- USB: Connect to PC or power bank (5 V)
- Battery: 3.7 V Li-ion on JST-PH (2-pin). Recommended:
- Samsung 21700 (4900 mAh, 9.8 A) with PCM
- Fuse (1.5–2 A) inline for safety
- Board charges the battery via micro-USB (IP5306 PMU, ~1 A max)
This guide describes a compact, robust tube build for the LilyGO TTGO T-Journal (ESP32 + OV2640 + OLED) with a single 21700 Li-ion cell in-line behind the board. It’s designed for browser-based live video (AP mode) at http://192.168.4.1 using the PlatformIO firmware in this repo.
- Layout (front → back): window/endcap → TTGO T-Journal (camera faces out) → wiring gap (PCM/BMS + fuse) → 1× 21700 cell → rear endcap with SMA bulkhead (antenna) and vent.
- Goal: ~14–18 h runtime from a single 21700 (Samsung ~4900 mAh), robust range with SMA antenna, safe power with PCM + fuse.
- Tube target size: Ø 30–32 mm ID, length 200–220 mm (see dimensions below).
Core
- 1× LilyGO TTGO T-Journal (ESP32, OV2640, 0.91" OLED, u.FL; SMA antenna usually included)
- 1× Samsung 21700 Li-ion, ~4900 mAh, unprotected (e.g., 50E/48G class)
- 1× PCM/BMS (1S), 6–10 A rated (OVP/UVP/OCP/short protection)
- 1× Inline fuse (mini blade or polyfuse), 1.5–2 A on battery +
- 1× JST-PH 2.0 (2-pin) pigtail, to match T-Journal battery header (check polarity!)
- 1× u.FL → SMA female bulkhead pigtail (if not included on board/kit)
- 1× 2.4 GHz SMA antenna (stubby or whip)
Enclosure
- Tube: plastic or aluminum, inner Ø 30–32 mm, cut length 200–220 mm
- Front endcap with window:
- Option A: round acrylic disk Ø 25–28 mm, 2–3 mm thick, bonded inside cap
- Option B: 10–12 mm aperture hole (no window) if weatherproofing not required
- Rear endcap:
- 1× SMA bulkhead hole ~6.5 mm
- 1× vent hole 1–2 mm, covered by hydrophobic vent patch (Gore-type) or mesh
- O-rings / sealant: appropriate for your tube + endcaps (e.g., nitrile O-rings, silicone gasket, or silicone sealant)
- Mounting: small foam rails or a 3D-printed sled to center/secure board + cell
Wiring & consumables
- 22–24 AWG silicone wire (red/black)
- Heat-shrink tubing, Kapton tape
- Epoxy or RTV silicone (neutral cure) for window & strain relief
- Threadlocker (low strength) for SMA nut (optional)
Tools
- Drill bits: 6.5 mm (SMA), 1–2 mm (vent), 10–12 mm (aperture if no window)
- Soldering iron, side cutters, deburring tool
- Calipers or ruler, marker for layout
Known sizes
- TTGO T-Journal PCB: approx 65 × 24 mm (L × W)
- 21700 cell: Ø 21 mm × 70 mm (allow Ø 22 mm with wrap)
Recommended tube
- Inner diameter (ID): 30–32 mm
- Leaves space for 24 mm-wide board, 22 mm battery, foam, wiring
- Usable internal length: ≥ 180 mm
- 65 (board) + 70 (cell) + 20–30 (wiring/PCM/fuse) + ~15 (cap clearance)
- Cut length: 200–220 mm (room for endcap intrusion and seals)
Endcaps
- Front: either a clear window bonded inside, or a 10–12 mm aperture hole
- Rear:
- SMA bulkhead center hole ~6.5 mm
- Vent hole 1–2 mm (offset from center), covered with vent patch
[21700 Cell] + ----> [PCM B+] (battery protection)
- ----> [PCM B-]
[PCM P+] --> [Fuse 1.5–2A] --> JST-PH + --> T-Journal BAT+
[PCM P-] ---------------------> JST-PH - --> T-Journal GND
Antenna: u.FL (board) --> u.FL-to-SMA pigtail --> SMA bulkhead (rear cap) --> SMA antenna
Notes
- Keep leads short. Add heat-shrink over joints.
- Verify JST-PH polarity before first power (Red=+, Black=– on board header).
- Bond/strain-relief the pigtail so the u.FL isn’t stressed.
Front cap (window)
- Centered round window: Ø 25–28 mm acrylic disk (2–3 mm thick) bonded from inside
- Or: drilled aperture Ø 10–12 mm if no window is used
Rear cap
- SMA bulkhead: center drill Ø 6.5 mm
- Vent: offset drill Ø 1–2 mm, cover with vent patch/mesh
Deburr all holes. Test-fit SMA; ensure nut + washer seat cleanly.
-
Prep the tube
- Cut to 200–220 mm, deburr edges.
- Dry-fit both endcaps.
-
Front window (if used)
- Clean with IPA. Lightly scuff bonding surfaces.
- Bond the acrylic disk inside the front cap using RTV silicone (neutral cure) or thin epoxy.
- Ensure the window is flat and sealed around edges. Let it cure fully.
-
Rear cap pass-throughs
- Drill 6.5 mm center hole for SMA; mount bulkhead (nut + washer).
- Drill 1–2 mm vent; apply vent patch from inside (or mesh + breathable tape).
-
Power harness
- Solder PCM to the 21700 cell (B+ / B-).
- From PCM P+, go to fuse, then to JST-PH +.
- PCM P- to JST-PH –.
- Heat-shrink and label polarity.
- If shrinking the cell instead of a holder: add insulating ring on the + end; wrap neatly.
-
Board & antenna
- Attach u.FL → SMA pigtail to the board.
- Route the pigtail to the rear cap (avoid sharp bends).
- Connect JST-PH to the T-Journal battery header (double-check polarity).
- Optionally display the SSID/IP on OLED when you first power up (bench test).
-
Internal supports
- Use foam rails or a 3D-printed sled:
- Board channel width: 24 mm
- Battery channel diameter: 22 mm
- Provide 2–3 mm foam on contact points for damping.
- Leave 10–15 mm wiring slack between board and battery (strain relief).
- Use foam rails or a 3D-printed sled:
-
Final fit
- Insert the board (camera forward), then battery, then the rear cap.
- Ensure the camera lens is centered behind the window/aperture.
- Check that antenna nut is snug (add a dab of threadlocker if desired).
-
Sealing
- Use O-rings or a silicone bead in the cap grooves.
- Do not make the tube perfectly airtight — the vent is intentional.
- Protection: always use a PCM/BMS with unprotected cells.
- Fuse: 1.5–2 A inline on P+ after the PCM.
- Charging:
- Easiest: via the TTGO USB (IP5306 on-board, ~1 A → long charge time for 4900 mAh).
- Fastest/coolest: remove the cell and use a dedicated 21700 Li-ion charger.
- Thermal: do not run any onboard flash LED continuously inside a sealed space.
- Vent: keep the 1–2 mm vent open and protected (hydrophobic patch).
- Place the SMA antenna outside the rear cap; avoid metal endcaps near the antenna.
- Keep line-of-sight when possible; avoid wrapping the antenna tightly along the tube.
- Start with VGA framesize; tune SVGA/XGA only if stream is stable.
- The OLED shows SSID/IP so you can connect quickly.
- ✅ Polarity checked (JST-PH +/–)
- ✅ PCM wired correctly: B to cell, P to load
- ✅ Fuse installed on P+
- ✅ Antenna connected (u.FL fully seated)
- ✅ Stream test on bench (
http://192.168.4.1) before sealing - ✅ Vent present and covered
- Periodically inspect u.FL connection and SMA nut.
- Check seals and the front window for fogging/cracks.
- Recharge before deep depletion; Li-ion longevity is best between 20–80% SOC.
- If storing long term, leave the cell at ~50% and power off.
-
Power on the board
- OLED shows boot info
- Starts Wi-Fi Access Point:
- SSID:
ESP32CAM-AP - Password:
camstream123 - IP:
192.168.4.1
- SSID:
-
Connect your phone/laptop to Wi-Fi
- Open Wi-Fi settings → select
ESP32CAM-AP - Enter password
- Open Wi-Fi settings → select
-
Open browser
- Navigate to http://192.168.4.1
- You’ll see the control page
-
Control page functions
- Start Stream → begins MJPEG stream
- Stop Stream → stops
- Framesize → QVGA, VGA, SVGA, XGA
- Quality → JPEG quality (lower = better image, bigger size)
-
OLED display
- Shows SSID and IP for quick reference
- Updates on boot
- Use the supplied SMA antenna for reliable 50+ m range (line of sight).
- For outdoor housing (tube design):
- Place antenna at the plastic endcap for RF transparency
- Provide vent/relief for Li-ion safety (don’t seal airtight)
- Lower framesize (QVGA/VGA) → smoother stream, lower bandwidth
- Higher framesize (XGA) → sharper, but may drop frames
- Always use protected Li-ion cells or packs with a PCM/BMS.
- Add a fuse inline with the positive lead (1.5–2 A).
- Never charge a Li-ion cell in a completely sealed enclosure.
- Observe polarity on JST-PH connector (Red = +, Black = –).
- Power on → OLED shows
ESP32CAM-AP / 192.168.4.1 - Connect phone Wi-Fi to
ESP32CAM-AP - Open browser: http://192.168.4.1
- Click Start Stream → see live video
Open-source demo project.
Use and adapt freely for personal and educational projects.
No warranty for safety, fitness, or reliability.