I have a load of used AA/AAA batteries (0.9-1.2V), that I keep to run my LTC-3525 enabled projects like Funky v1 and v2; however the LTC-3525 will work down to 0.8V so the batteries are declared ‘dead’ for a second…
Re-vamping my Daikin Internet Air-conditioner controller
I’ve created a new shield for my micro Internet of Things gateway to allow driving an IR LED, added a micro SD card slot, FTDI pinout for easy programming and a visible status LED. I also added a TMP36 temperature…
Funky v2 now poses as LilyPad Arduino USB
In an effort to make the Funky v2 even easier to use, I decided to make it appear as a standard LilyPad Arduino USB by using the same USB VID/PID pair. This will enable using it with Arduino IDE without needing…
New ATMega32U4 board to use with nRF24L01
I laid out a new pcb design to eventually produce, it is a USB enabled ATMega32U4 @ 8Mhz/3.3V (same MCU as Arduino Leonardo) board with optional AAA battery holder on the back plus LC3525@3V boost regulator that will allow the thing to run off the…
nRF24L01+ power consumption footprint
I hooked my Dirt Cheap Low Power Wireless Sensor Node (DCLPWSN 🙂 ) to the scope to see what is going on during transmissions. I used this library for the test, and this code: /** * Pins: * Hardware SPI: *…
Dirt Cheap Low Power Wireless Sensor Node using nRF24L01+ 2.4GHz
I have mentioned before, that I have purchased couple nRF24L01+ units from eBay for the stunning $3 with delivery included. I decided to make some cheap tests this time, so went for a veroboard prototype. I got two blank DIP…
Cheap USB to 3.3V TTL FTDI Cable goes to the trash bin
I have a cheap USB to 3.3V TTL FTDI Cable that I bought on Ebay. It has been giving me some troubles ever since I got it, burned couple RFM12B modules along the way. I decided to hook it to…
Scooter tail light mod
I read an interesting post few months ago about a guy modding his motorcycle’s tail light so it is much more fancy. I had to try it out too 🙂 I have couple ATTiny85s lying around so in couple hours…
Interfacing with Paradox home security system
I have a Paradox home security system and I have long wanted to interface with it. I am most interested in its status (armed, disarmed) and the zone statuses. I can use the alarm status to send myself SMS when…
Low power serial keypad
I bought one of these keypads off ebay few days ago, and decided to try it out. These work pretty straight-forward, you have 8 pins – 4 for rows and 4 for columns. When you press a button, it creates…
Crazy high frequency PWM with ATMega32U4
Timer 4 on the ATMega32U4 is a high speed one, but I have never tried it out before. Now that I have a scope, I decided to toy with it. It can work from the internal PLL, meaning some really high frequencies…
Scope screenshots
One of the cool things about having a digital scope is that you can take screenshots and post them in blogs :). I wanted to check how a Funky v2 was behaving, so hooked one to measure its current consumption…
Oscilloscope
I have finally decided to get myself an oscilloscope, my choice ended up to be a Rigol DS1052E. The model seems to be pretty popular, and for a price tag of 309 EUR with delivery, I could no longer resist.…
Trying out Funky v2 with the LTC3108 energy harvesting board
I have recently added a MOSFET to Funky v2 so it can control the power state of the RFM12B module. This was done in an attempt to allow starting up from a gradually rising power source, like the LTC3108 energy…
Funky v2 rev 1
I haven’t been able to use my miniature nodes the Funky v1 or Funky v2 with my energy harvesting board yet, in the means of plug-and-forget type of solution. Basically the issue is that we have a slowly rising voltage from…
Soil moisture sensing revisited
I have previously created a DIY soil moisture sensor, but wiring it required couple resistors. I was recently reading a post by JCW on using a light sensor and figured I could simplify my setup using the same basic idea…
RFM12B End of Life
EDIT March 2015: [It has been two years since this post, and the RFM12B is still widely available. I guess the rumors at that time were exaggerated widely.] There has been bad news for the RFM12B ecosystem last week, namely the…
73062 transmissions with the Funky v2 low-power code and CR2032 battery
The Funky v2 loaded with my low power test code that I described here has stopped sending transmissions yesterday. The Funky v2 was powered by a fresh CR2032 battery with 220mAh capacity. I use an integer counter that overflowed few…
Wallpaper prank
I wish I did this for April 1st, but here is it anyway 🙂 I wanted to test out the HID keyboard features of the Arduino Leonardo compatible Funky v2, so during my research on the subject I accidentally stumbled…
Auto reconnect WiFi on Raspberry Pi
For a number of reasons I have my DD-WRT-based router shut down WiFi at nights, that though causes some inconvenience to my Raspberry Pi. I have it connected with a RTL8188CUS based WiFi dongle, the cheapest found on eBay. The problem is that…
Software I2C test
The Funky v2 is so small in size, that only few pins are available on the side header. This is because its main purpose is to interface with one, at most couple sensors while running on battery. The hardware TWI/I2C…
TCP/IP over RFM12B and Raspberry Pi as gateway
I have always wanted to connect my remote RFM12B -based nodes to the Internet, I have finally managed to do so. It was relatively easy, based on the excellent work of Adam Neilsen with his SerialIP library SerialIP is a port…
Funky v2 low power example
I have consolidated my accumulated so far experience on running the ATmega32U4+RFM12B based Funky v2 in low power mode in this example sketch. I managed to bring the power consumption down to 0.04mA, which makes it possible for the Funky v2 to run on…
Detecting USB connection on the Funky v2
When designing low-power code for the ATmega32U4-based Funky v2 (code, optimized for running on battery power), it is important to power down all unused peripherals as soon as possible in the code. The USB circuitry draws significant amount of power, so naturally…
Frequency counting test
This is something I long wanted to try out – frequency counting with my Funky v2. I used Albert’s Arduino frequency counter library for the purpose. I’d test it by doing 6 kHz PWM and try to count that. The interrupt…
Siri-like voice chat with Raspberry Pi : keep kids busy for a while :)
Here is a fun project to try out: a Siri-like voice talk with your Raspberry Pi, its a lovely way to attract youngsters and keep them entertained for a while. I use three components for the project, code is mainly…
The Raspberry Pi TFT PCB arrived
The Raspberry Pi TFT PCB that I described here has arrived yesterday; I quickly soldered my TFT on it and gave it a test. ll works great, here is a small demo:
Funky v2 as RFM12B to Raspberry Pi gateway
Funky v2 enumerates as a CDC device when plugged in to your Raspberry Pi without the need of any driver, so it is pretty easy to get it working as a RFM2Pi board. Useful If you decide that for some reason…
Video of the LTC3108 energy harvesting board with solar cell
I made a short video of the LTC3108 energy harvesting board with a solar cell. The test is done indoors, it was completely dark outside. Light source is a single 23W CFL bulb, around meter away. The breakout board has…
More “Gotchas” on the LDO regulator issue in Funky v2
Apparently, as I have found out, the MCP1703 will leak current if voltage applied to the output gate and nothing on the input, while the MCP1700 does not. This is the case, when you power the Funky v2 from a CR2032…
Funky v2’s LDO to blame for high sleep current. Now fixed
I have confirmed by suspicion that the on-board LDO voltage regulator is to blame for my troubles as described yesterday. I experienced the exact same situation with battery powered Funky v2 high sleep current as @Capnbry describes here, so I…
High sleep current issue with Funky v2 sorted out
The Funky v2 high sleep current situation turned to be my multimer going crazy when using a noisy 3.3V power supply. When powering the Funky v2 from couple AA batteries, I got 0.13-0.14mA sleep current using the sketch below. Still…