Embedded Electronic Designs
Featured
Does your motorhome, caravan or campervan fridge struggle in hot weather?
Fridges work hard in summer — and without proper airflow the fridge becomes inefficient.
FridgeAir fixes that.
It continuously monitors the temperature difference between the top and bottom of the cavity and chimney behind the fridge. When the top starts rising faster than the bottom — a reliable early warning that natural airflow is no longer keeping up — FridgeAir automatically starts circulating air before temperatures climb high enough to affect cooling performance.
Quiet when cool. Powerful when hot. You’ll never think about it again.
No app. No Bluetooth. No setup. Just plug it in and it works.
What FridgeAir does
Smart delta-driven cooling — unlike traditional thermostatic controllers, FridgeAir reacts to temperature difference, not just temperature.
Continuously monitors top and bottom temperatures with precision digital sensors.
Variable fan speed — ramps up with temperature, very quiet when cool.
Protects your leisure battery — fans cut automatically if voltage drops too low for a sustained period, then restart when charging resumes.
Single-sensor mode — works with just one sensor and one fan. FridgeAir automatically switches to a tuned single-fan profile so performance stays strong even when dual-sensor/fan routing isn’t practical.
Green LED heartbeat confirms the unit is alive and working.
Double-flash warning when the leisure battery voltage is marginal — the unit hibernates until the battery recovers.
Boot self-test — both fans run briefly at startup so you know everything is working.
While idle and monitoring, FridgeAir draws only ~65µA (~0.002Ah per day), helping preserve your leisure battery.
PCB protected with MG Chemicals 419D acrylic conformal coating for moisture and vibration resistance.
Colour-coded and clearly labelled — wiring takes minutes
A — 12V DC power input
B — Top sensor (RED heat shrink)
C — Bottom sensor (BLUE heat shrink)
D — Top fan output
E — Bottom fan output
What’s in the box
Controller only option
FridgeAir controller in carbon-fibre PLA enclosure
2 × DS18B20 temperature sensors (red = top, blue = bottom)
2 × sensor mounting clips
2 × cable ties
Quick Start Guide
Complete kit adds
2 × 12V DC 120×120 mm fans with mounting hardware
Technical
Protected input — onboard self-resetting polyfuse (3.5A hold / 6A trip) and reverse polarity protection safeguard both the unit and your vehicle wiring from wiring faults and transient events.
Supply: 12V DC (leisure battery).
Fan output: 12V PWM, dual channel, variable speed.
Top fan triggers above 45 °C, full speed at 65 °C.
Bottom fan triggers above 40 °C, full speed at 65 °C.
Separate fan profiles optimise airflow direction and minimise unnecessary fan operation.
Smart delta-latch — automatically runs the bottom fan when the top is significantly hotter, ensuring cold-air circulation even before the bottom temperature rises.
Leisure battery warning below 12.3V, protection cuts in below 12.0V sustained, auto-recovers above 12.4V.
Flexible fan outputs — each channel can drive two fans in parallel (max 0.5 A / 6 W per channel). Dual fans top and dual fans bottom is fully supported.
Single-sensor mode — use the blue sensor and one fan at the top of the chimney. FridgeAir automatically switches to a more enhanced profile.
For full photo gallery including PCB detail and complete kit contents [click here]
This is the one for people who know. A hand-built, DCF77 radio-controlled ePaper clock with a Space Invaders faceplate faithful to the original 1978 Taito cabinet. Alien formation on teal bezel, three-layer filament-swap construction. In the top left corner, a Space Invaders sprite tells you whether it’s BST or GMT. Included with every clock is a hand-finished Space Invader and a TAITO badge with easel — display them together or separately. At 36.5 cm wide and 23 cm tall this is a proper statement piece.
Radio signal note: This clock automatically synchronises to the European DCF77 radio time signal (mainly received across Europe). Outside of DCF77 coverage the clock will still keep accurate time and can be set manually. Check DCF77 coverage for your area by [clicking here].
It keeps perfect time without WiFi, Bluetooth, or an app. Unbox it, plug it in — it’s already set and syncs automatically to the DCF77 atomic time signal once a week to stay accurate.
No app. No Bluetooth. No setup. Just big digits — and aliens.
What Bigtime displays:
Time — large 12 hour display, AM/PM indicator
Date — day, date and month
Indoor temperature — °C
Indoor humidity — %
Dew point — comfort indicator
Comfort label — Dry, Comfortable, Pleasant, Humid and more
BST/GMT indicator — Space Invader switches automatically
Battery level — 4 bar indicator
What Bigtime does:
Synchronises to the DCF77 atomic radio time signal — accurate to the second
Automatic BST/GMT switching — never needs adjusting
Syncs automatically at 2am weekly — always correct
ePaper display — crisp and clear in any light, zero power between updates
Push button — single tap illuminates the night LED strip
Battery backed — runs for weeks on a single charge
USB-C charging — standard cable, not included
Mounting options:
Desktop stand included — sits on any flat surface
Magnetic mount — magnetic strip fitted to rear, two metal adhesive discs included — stick to any smooth surface, clock attaches and detaches in seconds
No drilling required for either option
What's in the box:
Bigtime Space Invaders Edition clock unit
Desktop stand
2 x metal adhesive discs for magnetic wall mounting
Hand-finished Space Invader
TAITO badge with easel
Quick Start Guide
USB-C cable not included — standard 5V USB-C
Technical:
Display: 5.79 inch ePaper, 792 x 272 pixels, black and white
Time signal: DCF77 77.5kHz radio
Sync schedule: 2am weekly, 3am fallback
Sensor: SHT40 temperature and humidity
Battery: LiPo, USB-C charging
Hand-built and tested in the UK by Digconn Systems
Check DCF77 coverage for your area [click here]
Storing your motorhome or caravan outside over winter? Condensation and damp are your biggest enemy. Cold nights, temperature swings and stagnant air create the perfect conditions for mould, bad smells, rot and expensive interior damage — all while your vehicle is sitting unattended for months.
AirMix helps with that.
Leave it inside your habitation area over winter and it silently monitors temperature and humidity, calculates the dew point, and automatically runs opposing fans to circulate air before condensation can form. Completely battery backed — no mains, no vehicle power, no hookup needed. Just switch it on, close the door, and leave it to do its job all winter long.
No app. No Bluetooth. No setup. Switch it on and walk away.
What AirMix does:
Monitors temperature and humidity continuously using a precision SHT40 sensor
Calculates dew point — the real indicator of condensation risk, not just humidity alone
Pre-sniff pulse — runs fans briefly before each sample to flush stagnant air from the AirMix chimney and get a true reading
Automatically runs opposing fans when condensation risk is detected — one draws air in, one pushes air out
Adaptive monitoring — increases check frequency to every 5 minutes after a dew event until conditions are safe
Seasonal activation latch — LED shows 2 flashes after a dew event so you know it has been working during storage
Battery backed — runs completely independently from a quality RS Pro 18650 lithium-ion cell
USB-C charging — charge before you store, lasts the winter
LED guide printed on the enclosure — 1 flash = ready, 2 flashes = activated, 3 flashes = charge soon
Boot self-test fan dance — confirms both fans working at startup
Standard camera tripod mount — brass insert fitted, position it anywhere in your habitation area
Freestanding or tripod mounted — goes anywhere:
AirMix sits flat on any surface or mounts directly onto a standard camera tripod using the brass insert fitted to the base. Position it exactly where condensation is a problem — under a bed, on a worktop, in a wardrobe space. No drilling, no permanent installation, completely repositionable season to season.
Before you store for winter:
Charge AirMix fully via USB-C
Switch on and confirm 1 flash heartbeat — ready
Place in your habitation area
Close up your motorhome or caravan and leave
When you return in spring — 2 flashes on the LED tells you AirMix has been working. Your van is protected.
What's in the box:
AirMix unit in carbon fibre PLA enclosure
RS Pro 18650 lithium-ion cell installed — PCB protected, overcharge and over-discharge protected, UN and RoHS certified, original manufacturer's packaging included
Quick Start Guide
Technical:
Supply: RS Pro 18650 Li-ion cell, 3.7V 2600mAh, USB-C charging
Fans: dual opposing 5V PWM, variable speed
Sensor: SHT40 precision temperature and humidity
Dew point algorithm: August-Roche-Magnus
Activation threshold: RH ≥ 70% or dew point margin ≤ 2.5°C
Fan run: full power 60 seconds, cruise 70% for 5 minutes
Check interval: 1 hour normal, 5 minutes after dew event
LED: 1 flash = ready, 2 = activated, 3 = low battery, 6 = sensor fault
Tripod mount: standard ¼" camera fitting via brass insert
Handbuilt and tested in the UK by Digconn Systems
For full photo gallery including PCB detail and complete kit contents:
[Click here to view]