Phones Archives - A Leslie Wong Blog

October 15, 2021October 15, 2021

Google Pixel 4a 5G Broken Screen Replacement

Google Pixel 4a 5G phone with broken screen

In November 2020, when I bought my Google Pixel 4a 5G, I also bought a Spigen Ultra Hybrid Case (#ad) for it. Sometimes I use it. Last Monday, a time that I didn’t use it, the phone fell out of my back pocket onto concrete, landing on its lower left corner and cracking the screen.

After finding out that I hadn’t purchased device coverage for the phone, I bought a replacement display (#ad) from Amazon for $169.44. From the various choices of Pixel 4a 5G replacement displays on Amazon, I chose the (difficult for me to pronounce) YWLRONG replacement display because it also came with a great set of tools: double side adhesive, an anti-static spudger, precision tweezers, six different screwdrivers, a guitar pick, SIM card ejection tool, suction cup, stainless steel pry tool and B7000 adhesive. I really only had to use the suction cup, stainless steel pry tool and a hairdryer to heat up the adhesive to remove the display. After cleaning the old glue from the case, I used B7000 adhesive to install the new display. It was very straightforward.

Google Pixel 4a 5G phone with broken screen removed

I usually turn to iFixit for great instructions on fixing stuff and there was a nice writeup, Google Pixel 4a 5G Screen Replacement, by: Sam Omiotek (and 2 other contributors). This Google Pixel 4A 5G Screen Replacement YouTube video was the most helpful of the several I viewed.

September 25, 2019March 31, 2023

iPhone 11 Pro Camera Lenses – Focal Length Comparison

Apple iPhone 11 Pro lenses (Photo: Apple Inc)

The iPhone 11 Pro phones come with triple 12MP Ultra Wide, Wide, and Telephoto cameras. The iPhone focal length of the lenses are 1.54mm, 4.25mm and 6mm. Their 35mm equivalent focal lengths are 13mm, 26mm, and 52mm, respectively. Cinematographer Newton Thomas Sigel gives a great explanation of the different effects of wide, normal and telephoto lenses.

iPhone 11 Pro Max Ultra Wide Camera – lens focal length 1.54mm (35mm equivalent: 13mm)

iPhone 11 Pro Max Wide Camera – lens focal length 4.25mm (35mm equivalent: 26mm)

iPhone 11 Pro Max Telephoto Camera – lens focal length 6mm (35mm equivalent: 52mm)

In the late 1970’s, I used the Nikon 13mm f5.6 lens on the Nikon F2 camera. The Nikon 13mm lens had a 118 degree angle of view and in its time, it was remarkable in that it was a rectilinear lens. The extreme angle of view opened up new creative possibilities in all types of photography including indoor, architectural and landscape photography.

The iPhone 11 Pro’s Ultra Wide camera angle of view is 120 degrees. When using the Wide and Telephoto cameras with iOS 13.1 camera app, the Ultra Wide lens enables a preview of what is outside the frame. This outside the frame information is also captured in the Wide and Telephoto cameras to enable post processing cropping without losing image information. This setting can be enabled in Settings -> Camera -> Photos Capture Outside the Frame.

iOS 13.1 Camera App screen – Ultra Wide field of view (Photo: Apple Inc)

October 13, 2012April 1, 2020

MintyBoost 3.0

I built a pocket size USB charger using a MintyBoost 3.0 USB charger, a 3.7 v, 2600 mAh LiIon battery and a built-in LiIon battery charger in an Altoids Wintergreen Mints tin. It can be used to recharge a cell phone, iPod or other small USB rechargeable device.

I’ve had adafruit.com‘s MintyBoost 3.0 kit and USB LiIon/LiPoly charger (this is v1.1) for a while but I never put them together. I liked the size of the Altoids gum tin of the previous MintyBoost versions I have built but I wanted a little more charging capacity than 2 AA batteries could provide. I wanted a suitable battery and enclosure that didn’t compromise charging capacity and size.

Using ladyada’s calculations for battery power, I decided to use a 3.7v 2600 mAh LiIon battery.

The battery’s capacity:
MintyBoost mWh = 3.7V * 2600 mAh = 9620 mWh input

The amount of current it can provide:
Output mAh @ 5V = 9620 mWh / 5 * 80% = 1539 mAh output (80% is the conversion efficiency)

Number of iPhone 4S recharges = 1539 mAh / 1430 mAh (iPhone battery capacity) ~ 1.1

The MintyBoost kit requires the soldering of a few components to a circuit board. I also made two mods to the internal battery charger. With this version (1.1) of the adafruit LiIon battery charger, removing the resistor R4 and replacing it with a 1K ohm resistor allows the internal battery to be charged at 1000 mA.

The internal battery charger has connections for external status LEDs. I connected current limiting resistors between the board and LEDs, then mounted the LEDs in holes in the Altoids tin. The green LED indicates that the internal battery is charging and the yellow LED indicates a fully charged battery. (LiIon/LiPoly charging tutorial at Adafruit Learning System)

The battery and circuit boards are mounted in the Altoids tin with double sided foam tape. I made a miscalculation in the height of the LiIon charger taped to battery – the cover won’t close when the charging cable for the internal battery is attached.

To charge the internal battery, a USB Mini B plug supplies the power to the internal battery charger as in the photo above. To charge a device, a USB Standard A connector is used. There’s also enough room in the Altoids tin for storing an Apple 30-pin to USB Cable.

MintyBoost 3.0 in Altoids Wintergreen Mints tin

Below are charging test results with an iPhone 4S starting with battery at 49%:

Time (minutes) Charge (%)
0:00 49%
0:15 58%
0:30 66%
0:45 75%
1:00 83%
1:15 89%
1:30 93%
1:45 96%
2:00 97%

If you are interested in the MintyBoost design process: https://learn.adafruit.com/minty-boost/process

March 20, 2011May 21, 2020

Devil’s Slide – Total Recall

I was reading Robert Scoble’s post about the AT&T-T-Mobile deal (One bad company buying another: AT&T buys TMobile) and he mentioned, “Devil’s Slide (cell service) is non-existent for AT&T and TMobile, but works the entire way on Verizon for me.”

Devil’s Slide is an area of steep cliffs along the Pacific Ocean about five miles south of San Francisco, California. This stretch of Highway 1 can induce acrophobia if you start thinking about driving your car off the road. This is a good piture of it showing the road slicing right across Devil’s Slide. This part of the highway is “remote,” in that the extreme terrain doesn’t allow for much habitability for a few miles on either side. Maybe that’s the reason AT&T and T-Mobile didn’t care about a dead spot for a few miles, though I wouldn’t recommend checking your phone’s signal while driving this stretch of road, especially if you are driving in a sporting manner.

The California Department of Transportation (Caltrans) started building a tunnel in 2005 to bypass the area prone to rock slides so Highway 1 won’t keep getting closed. The tunnel is 4200 feet (1,280 m) long and will be completed in 2011. On October 1, 2010, they punched through one of the tunnels. I just wrote all this because the video reminded me of Total Recall.

January 8, 2011July 25, 2021

A Nexus S Case

I bought a Samsung Nexus S the day it was released, last December 16. Android 2.3 (Gingerbread) gives the Nexus S considerably more functionality than the last phone I bought, though it costs about 26 times more.

The only other thing I wanted for the phone was a silicone case. I ordered the Amzer Silicone Skin Jelly Case on December 17, 2010 and it finally shipped January 6, 2011.

The case covers the side and the back of the Nexus S with clean cutouts on the back for the camera, flash and speaker. The bottom of the case has cutouts for the headphone jack and charging port. On the side of the case, there are raised bumps for the volume and power switches that work OK.

There is a slightly raised edge around the front of the case, which allows for putting the phone face down on a flat surface without concern about scratching the front. The Amzer case will provide scratch protection for the back and sides of the phone and a certain degree of impact protection, though I don’t really feel like testing that capability.

The case is available in eleven colors: black, gray, transparent white, hot pink, purple, maroon red, blue, orange, green and baby pink…

Update July 20, 2011: I have since switched to the Incipio Feather case because I found that the Amzer silicone case made it difficult to pull the phone from my pants pocket. The Incipio case is a hard shell but with a soft touch coating that won’t scratch the phone and is much easier to put in and take out of my pocket. I have even dropped the Nexus S in the Incipio case from 4 feet onto concrete with no damage.