RPi GPS/NTP for Dashcam System

This is more notes for my future self in case I ever have to get ntp working using a gps time source. The biggest lesson was to wait for a few minutes before giving up on ntp getting the GPS signal.

This is for an Adafruit Ultimate GPS on my Raspberry Pi 2. GPIO 18 is connected to the PPS pin on the GPS. I'm connected to the GPS using a USB to serial adapter.

/etc/udev/rules.d/09-pps.rules
KERNEL=="ttyUSB0", SYMLINK+="gps0"
KERNEL=="pps0", OWNER="root", GROUP="tty", MODE="0777", SYMLINK+="gpspps0"

/etc/ntp.conf

server 127.127.20.0 mode 16 maxpoll 6 prefer

fudge 127.127.20.0 time2 -0.301 flag1 1 refid GPS

/etc/default/gpsd

START_DAEMON="true"

# Use USB hotplugging to add new USB devices automatically to the daemon

USBAUTO="true"

# Devices gpsd should collect to at boot time.

# They need to be read/writeable, either by user gpsd or the group dialout.

DEVICES="/dev/ttyUSB0"

# Other options you want to pass to gpsd

GPSD_OPTIONS="-n -F /var/run/gpsd.sock"

/etc/modules

pps-gpio

/boot/config.txt

dtoverlay=pps-gpio,gpiopin=18

Micro-USB Powered Dog Feeder

I'm not a huge fan of stationary devices that require batteries to operate. I've had 2 Aspen Le Bistro Portion-Control Automatic Pet Feeders since February of 2015 and they've performed very well. The only problem is that when the batteries get low, they don't feed the dogs and so far, the low battery light hadn't worked. The label on the bottom of the feeder clearly showed I needed 4.5V at 500ma to power the feeder. To anyone who works with electronics, these numbers are almost identical to USB power (5V at 500ma) which gave me the idea.

Residential Cable Pathways and Conduit

Hello world. Sorry it's been a while. I got a job at Google and moved to California therefore my posting frequency had gone down for a bit. It's a mix of being very busy and general NDAness of working at Google. 

Riser between garage and attic

I'm adding a home security system as well as adding wired network to several locations in my new home in San Jose. After having some very weird and un-reusable pathways in my last house, I decided to implement some best practices for wiring by installing actual conduit to my wiring closet (office closet). I found a great space between my garage and the attic that allows the venting of the water heater and furnace as well as the main ductwork for the upper floor. It also shares a wall with the office closet which is an ideal location for network switches and the alarm system. My hope is that this will allow me to pull future cable with a pull-string through the conduit instead of drilling more holes or ripping apart the drywall for another pathway.

Assembling a wireless car charger

While it didn't make sense for me personally to use a wireless charger in the car, it may work for you. Here's how I made one out of all Samsung accessories without any soldiering skills.

Wireless charging, is it a myth?

I currently use the Samsung Desktop Dock for Infuse 4G on my nightstand for my GS4. It fits the phone quite well, has a port out the back that lines up nicely with the speaker and activates dock mode (which launches Dock Clock). I decided to replace this setup with the Tylt Vu, a recent kickstarter project. The Vu allows the phone to wirelessly charge at a 45 degree angle so you can still see it while charging (one of the major problems with Qi). Unfortunately, it doesn't stay connected to the phone as there is some sort of incompatibility with the official Galaxy S4 back plate. Both are fully Qi compliant so very frustrating. It's also worth mentioning that the Desktop Dock worked with both my GS3 and GS4 and cost a whopping $10. It takes the same amount of time to dock in either the Vu or the Infused dock but the Infuse dock charges twice as fast. Strike 2.

Galaxy S4

True to my word I bought the Galaxy S4 the week I got back from vacation. It's simply awesome. It took a little while to get used to the larger device size but I picked up an iPhone 5 the other day and wondered how I ever squinted at that tiny little screen. I picked up an iPhone 4 and actually gave a full "ha!" out loud. I am just floored by all of the features and options with this phone. My only disappointment initially was that their isn't a stable version of Cyanogenmod out there for GS4 (SPHD-720) yet. The good part is, I really got to have some hands on experience with TouchWiz and it has come a long way since I used the Samsung Galaxy S 4G. I would have missed out on the amazing camera software in TouchWiz not to mention some of the really fun features . My Bluetooth is working much better now. It turned out that it was Waze that was intercepting the pause/play controls.

I went whole-hog on the wireless charging and purchased a Tylt Vu, Samsung Galaxy S4 charging kit and the Samsung Universal Car Mount. My plan is to integrate the charging kit into the car mount with some mad dremmel skills. I'm hoping I'll be able to connect the car mount to my proclip like I was able to with the Samsung Infuse car mount I was using for the GS3. I'll post when I get it done.

I also picked up 2 packs of TecTiles 2 in my order to give those a try. I installed NFC Task Launcher and created a 4 minute timer for my french press process. I simply set my GS4 on top of the coffee grinding after I've ground the beans and it starts the 4 minute brew timer before I plunge and pour the coffee.

iOS to Android - Take 2

Google Now was the hook. I immediately fell in love with the intuitive and simple nature of the Google Now app and it's great little "cards" that show my next event, how long to get home, current flight status and a whole host of other great information. Google voice search lives up to everything Siri failed to deliver. It's fast, accurate, responsive and informative. I wanted more, but to get more, I had to do the unthinkable, I had to give up my iPhone 5.