PIC16F88 Delorme Tripmate GPS Logger

This project focused on creating a simple serial data logger for the Delorme Tripmate (also known as the GPSTripmate). The Tripmate is an older GPS receiver that can be purchased on eBay for <$20. I happen to have one that my family used a couple of years ago and it is still in great shape. It has been sitting in the back of my car for the past four years, so I finally decided to put it to good use. The plan was to create a GPS data logger that would record the position of the unit and allow me to read back the latitude and longitude after acquiring the data. My ultimate goal will be to use a small backpack to record my runs (once the weather warms up). This was a fun experiment because not only did I need to interface the PIC16F88 to the Tripmate, but I also needed to parse the output and implement an efficient storage solution. Read on to find out more information about the project, see the schematic and soure code I wrote, and find out how the data was visualized. Read More

Website Host Transfer Complete + Sparks

I’ve completed the server move and the DNS changes, so hopefully everything will now work. There was a problem with the email program (cgiemail) during the transfer, but it seems as though I resolved the problem by using a different script (FormMail). Please feel free to send me an email or leave a comment in this post if there are any problems.

High Voltage Sparks Over and Through Red LED 2/3

As an added bonus, I’ve attached some pictures of sparks generated with my high voltage power supply, which I was able to fix. It appears as though the old MOSFET had blown, so I was able to recreate the circuit with no issues. Continue to the post for a few more pictures. Read More

Changing Website Hosts

For the past two years I’ve hosted my website using QualityHostOnline and the traffic to my website and bandwidth usage has steadily increased every month. I’m very happy about this, but unfortunately this month I’m afraid I might go over my alloted bandwidth of 2 GB.

I’ve decided to change my website hosting to a higher bandwidth host (AN Hosting) as a long term solution. Hopefully there won’t be any issues, but please let me know if there are!  I highly recommend QualityHostOnline as a very affordable host for small websites needing <2 GB of bandwidth each month; I’ve never had any serious problems that have not been solved by their support staff within 24 hours.  I’ll let you know how AN Hosting turns out.

Royal Blue Luxeon K2

Royal Blue Luexon K2Lowe’s had a 1 Watt Luxeon Plastic Flashlight on sale for $2.50 recently. I ordered one online for in-store pickup and was able to get one of the last flashlights available at the store closest to me (they actually didn’t have enough to fulfill all of the orders, but I was able to convince them that I deserved one). When I brought it home and broke it open I found a nice white 1 watt Luxeon star hex (LXHL-MW1D) bolted to the top. The flashlight itself felt relatively cheap and flimsy, so I decided to find out what I would do with it and how I could modify it. The flashlight used 3 1.5V AA batteries in series (i.e. 4.5V open circuit) and had a 1 Ohm resistor in series to limit the current to the LED. White flashlights are nice, but sometimes you need to just have fun. So, I took one of the Luxeon K2 Royal Blue LEDs (LXK2-PR12-L00) that I had purchased with Matt Kocsis and dropped it in. Read More

Updated Resume

I’ve updated my resume web page to include information about a conference paper that I co-authored with Dr. Hong Z. Tan at the Haptic Interface Research Laboratory (HIRL), where I have been working for the past semester:

Cholewiak, S., & Tan, H.Z. (In Press). Frequency analysis of the detectability of virtual haptic gratings. Proceedings of the 2007 World Haptics Conference. Tsukuba, Japan: WHC.

I have also included information about published papers and presentations in which I have been acknowledged.