Kurt Tomlinson's Blog

Modding a Franklin R850 Wifi Hotspot for a Car

I just got a new car with Android Auto, and I'm doing a little bit of work to make it work the way I like. The first problem with Android Auto is that it (mostly) requires a data connection for navigation. In this post, I add a hotspot with free data to my car that turns on and off automatically with my car.

electrical-engineering | 2017.10.15 18:32 | Kurt Tomlinson

Solutions to Common Altium Problems

Typically I enjoy using Altium at work for schematic capture and PCB layout, but occaisionally it'll give me some problems when I try to synchronize my PCB file with my schematic. When syncing, I'll get a lot of error messages about unmatched nets and failures when matching unique identifiers. In the past I'd try my best to backtrack what I'd changed in the schematic until I could get an error-free sync. Recently I found there are a couple things that I can do to quickly and easily fix these problems in 99% of cases.

electrical-engineering | 2017.07.09 05:00 | Kurt Tomlinson

Raspberry Pi Projects You Can Actually Do - Part Five: VPN

If you use public WiFi, you need a VPN. You can pay to use a commercial solution, or you can set one up in your own home for free. The problem with using public WiFi is that any data you send to an HTTP website is in the clear and available for anyone to read. A VPN encrypts your web traffic from your phone/desktop and sends it to the VPN server. Your traffic then proceeds to its destination encrypted or not based on if you're visiting a website over HTTP or HTTPS. The important part is VPNs make it so that no one sitting in the same cafe as you can snoop on your web traffic. Finally, VPNs can also be used to access location-locked services like Netflix even when you're travelling abroad. When you use a VPN, it's just like you're browsing the web from your home.

electrical-engineering | 2017.04.02 05:00 | Kurt Tomlinson

How to Choose Decoupling Capacitors

I recently took a class about EMI (electromagnetic interference) and EMC (electromagnetic comapatibility). For me, the highlight of the class were the PCB design tips. Among those tips were a set of steps for designing the bypass capacitor network for an IC on a PCB.

electrical-engineering | 2016.12.25 06:00 | Kurt Tomlinson

LED Night Light Tear Down

I recently bought a pack of LED Night Lights from China on Amazon. They were very cheaply made, so of course I wondered what they were like on the inside. Today I tried to unplug one from the wall to move it to another outlet, and the front cover came off. Since it practically disassembled itself for me, I decided to take a closer look at its circuit and figure out how it worked.

electrical-engineering | 2016.10.23 21:41 | Kurt Tomlinson