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.
Testing the RFM12B shield on a WorkerB! – swapping radio modules on the same board works as intended.
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.
nRF24L01+ range testing
nRF24L01+ range testing with a ping-pong sketch pair between a WorkerB! and my dirt cheap wireless sensor node.
The WorkerB!
Meet the WorkerB! – the ATmega32U4 + nRF24L01 board gets a name and 5 test PCBs, its job is to collect and transmit data.
3D printed Stevenson screen
A 3D printed Stevenson screen for my Funky+DHT22 – proper airflow instead of a black box with a few drilled holes and 99.9% RH readings.
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.
Cheap DIY power monitor
A cheap DIY power monitor for my father – SCT-013-000 current transformer plus OpenEnergyMonitor resources, momentary and accumulated kWh.
7 months of sending and still going
7 months on the same CR2032 and the Funky+DS18B20 room temperature node is still transmitting – live chart included.
Logging manualy entered values to emonCMS using keypad
Logging body weight to emonCMS with a keypad and a coin-cell Funky v2 – punch in the scale readout, get a weight history graph.
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.
Re-vamping my Daikin Internet Air-conditioner controller
A new IR blaster shield for the uIoT gateway – SD slot, FTDI pinout, TMP36 sensor, and a re-vamped Daikin Internet AC controller.
Funky v2 now poses as LilyPad Arduino USB
The Funky v2 now poses as a LilyPad Arduino USB – same VID/PID, so the stock Arduino IDE accepts it without modifications.
New ATMega32U4 board to use with nRF24L01
A new ATmega32U4 board for the nRF24L01+ – USB, 8MHz/3.3V, and a boost regulator that runs the whole thing off a single AAA battery.
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?
Cheap USB to 3.3V TTL FTDI Cable goes to the trash bin
My cheap ebay ‘FTDI’ cable outputs 5V on the supposedly 3.3V lines – scope proof, two dead RFM12Bs, straight to the trash bin.
Scooter tail light mod
Modding a scooter tail light with an ATtiny85 – a couple of hours from blog inspiration to fancy blinking.
Interfacing with Paradox home security system
Tapping into my Paradox home security system to read armed/disarmed state and zone statuses – free presence data for home automation.
Low power serial keypad
Trying out a cheap ebay matrix keypad as a low power serial keypad – groundwork for battery powered input projects.
Crazy high frequency PWM with ATMega32U4
Toying with Timer 4 on the ATmega32U4: PLL-driven PWM up to 8MHz, verified on the scope.
Scope screenshots
First scope screenshots: measuring the Funky v2’s current consumption via the voltage drop over a not-quite-10-ohm resistor.
Oscilloscope
I finally bought an oscilloscope – a Rigol DS1052E at 309 EUR delivered – and spent the evening exploring what I’d been missing.
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.
Funky v2 rev 1
Funky v2 rev 1: solving the RFM12B’s 0.68mA startup draw that kept my nodes from booting off the energy harvesting board.
Soil moisture sensing revisited
Soil moisture sensing with just the ATtiny’s internal pull-up and an analog input – no external resistors this time.
RFM12B End of Life
The RFM12B was declared End of Life – what it meant for my projects and the ecosystem. (Spoiler from 2015: it never really died.)
73062 transmissions with the Funky v2 low-power code and CR2032 battery
73062 transmissions from a Funky v2 on one 220mAh CR2032 – the low-power code held up until the battery finally quit.
Wallpaper prank
Testing the Funky v2’s HID keyboard mode with a USB Ducky style wallpaper prank – sorry, colleagues.
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.