Detecting AC presence with a NE2 neon lamp and an LDR – a low power alternative to my non-contact detection experiments.
Detecting AC
Voice controlling things with a smartphone and Raspberry Pi
Voice controlling the TV and heat pump with a smartphone and a Raspberry Pi – I’m no voice control fan, but this one earns its keep.
My dog as smart wireless DVR sensor
My dog turns out to be an excellent motion sensor – correlating her barking on the DVR with alarm events, 25km from Sofia.
Control LG smart TV over the Internet using a Raspberry Pi
Controlling an LG smart TV from the shell with a Raspberry Pi and a stripped-down Python script – a 5 minute home automation project.
Tweeting my house’s power usage as sparkblocks
Tweeting my house’s power usage as sparkblocks – unicode sparklines squeeze a full day’s trend into a single tweet.
The YAPM PCB is done
The YAPM (Yet Another Power Monitor) PCB is done and preliminary tests pass – built between a new job and scarce hobby hours.
OLED status display on the RFM2Pi board
The RFM2Pi board gets a 6 pin port that happens to exactly match the Digole 0.96″ OLED – instant plug-on status display.
Raspberry Pi kernel with Frame Buffer TFT support
Adding FBTFT frame buffer support for the 1.8″ TFT to Raspbian in 5 minutes flat – @notro’s work ends the kernel patching nightmare.
Door sensor
Toying with a cheap magnetic reed switch door sensor – wireless open/close events for doors and windows via a Funky.
Raspberry Pi root file system in read-only mode
Mounting the Raspberry Pi root file system read-only – the next step after USB flash also proved corruptible on power loss.
Pong clock on Raspberry Pi + 1.8″ TFT
A pong clock on the Raspberry Pi and my 1.8″ TFT – adapting Don Clark’s code for the ST7735R frame buffer.
Putting Raspberry Pi’s hardware watchdog to work
Putting the Raspberry Pi’s built-in hardware watchdog to work – automatic reboots when the Pi hangs, no external hardware.
Moving the root file system of Raspberry Pi to external USB drive
Three corrupted SD cards later: moving the Raspberry Pi root file system to a USB drive to survive our frequent power outages.
Flood alarm
A wireless flood alarm after my father’s leaking pipe flooded his place for days and cost thousands of Euro – cheap insurance.
Tweeting coffee machine using Raspbery Pi
Connecting my coffee machine to Twitter with a Raspberry Pi – a silly social appliance and a good learning exercise.
Wireless body temperature monitor/logger
A wearable wireless body temperature monitor for sick kids – remote logging plus a bedside status display with an alarm.
OLED analog clock
Adding an analog clock face to my OLED status display, plus a bitmap thermometer tracking the solar water tank temperature.
Raspberry Pi email/SMS doorbell notifier + picture of the person ringing it
Step-by-step Raspberry Pi doorbell notifier: email/SMS plus a webcam snapshot of whoever is ringing. A simpler follow-up to my SMS doorbell.
High AC mains voltage
My house sits second to the transformer and the multimeter agrees with the cheap one: AC mains voltage is high. Time to log it properly.
Optimizing DS18B20 code for low power applications
Cutting the DS18B20’s 750ms conversion time by dropping resolution – optimizing the sensor code for low power battery nodes.
Miniature OLED status display with Funky v2
A miniature 128×64 serial OLED as a status display for the Funky v2 – bright pixels, near-180° viewing angle, 30x28mm PCB.
DHT22 accuracy test part 2/2
DHT22 accuracy test part 2: steady 75.2% readouts against the expected 75% reference – the sensor is vindicated.
DHT22 accuracy test part 1
My DHT22 keeps reading suspiciously high relative humidity, so I set up an accuracy test – part 1, with a 3D printed Stevenson screen.
Texas Instruments SimpleLink CC3000 WiFi Module
First look at TI’s SimpleLink CC3000 – a fingernail sized $12 WiFi module that could shake up connected projects.
Running on ‘dead’ batteries
Running Funkys on ‘dead’ AA batteries – the LTC3525 boost keeps them alive down to 0.8V, squeezing out a second life.
nRF24L01+ power consumption footprint
Scoping the nRF24L01+ during transmissions to measure the real power footprint of my dirt cheap low power wireless sensor node.
Dirt Cheap Low Power Wireless Sensor Node using nRF24L01+ 2.4GHz
A dirt cheap wireless sensor node: $3 nRF24L01+ modules and blank DIP ATmega328s on veroboard – how low can the parts bill go?
Low power serial keypad
Trying out a cheap ebay matrix keypad as a low power serial keypad – groundwork for battery powered input projects.
Trying out Funky v2 with the LTC3108 energy harvesting board
Funky v2 with a MOSFET controlling the RFM12B’s power – trying to start cleanly from the LTC3108 energy harvester’s slow voltage ramp.
Auto reconnect WiFi on Raspberry Pi
Auto-reconnecting the Raspberry Pi’s cheap RTL8188CUS WiFi dongle after my router’s nightly WiFi shutdown – a small watchdog script.
Siri-like voice chat with Raspberry Pi : keep kids busy for a while :)
A Siri-like voice chat on the Raspberry Pi – speech-to-text, a chat bot and TTS glued together, keeps the kids busy for a while.
The Raspberry Pi TFT PCB arrived
The Raspberry Pi TFT PCB is back from the fab – TFT soldered on, working on first try, small demo inside.