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Chris Prossers' Blog


  1. Fun with Driving Solenoids

    I got frustrated trying to figure out the best way to drive some solenoids. I was looking for something foolproof that I didn't need to design myself. I'm trying to build as much as I can with JLCPCB Assembly which limits parts. I settled on the Infineon BTS724G. It's an automotive part that has all the protections you can think of. Good for an unmonitored art installation.

  2. 20 years in the making

    I tried to start this project back in 1999/2000 when I was living in San Francisco. It was inspired by a piece I saw in the gallery at Cellspace.

  3. Comparison of Firewalls for Home

    I’m curious about firewalls. I have a Protectli FW4B along with a backup edge router ER-X and decided to do some testing. There are a handful of different ideas I wanted to explore.

  4. IPFire and Centurylink Fiber

    I recently switched from pfSense to and got to learn the hoops needed for PPPoE over a vlan like Centurylink needs.

  5. Kindle Oasis holder for Levo Book Holder

    I have an older Levo Book holder. If you enjoy reading books and value your neck, I highly recommend this product. I get no kickbacks from the company for this, just a very satisfied customer Levo Bookholder.

  6. Medication Alarm

    I take medications. I'm also very sensitive to medications therefore I take them in liquid form so I can get the dosing dialed and just right. But I have a dilemma. They all look very similar, several of them even begin with the same letter, but I take them at different times of day. After a recent incident where I accidentally took the wrong one in the evening, and took five times my normal dose I decided to build this contraption to help remind me if I try and take out the wrong one at the wrong time of day.

  7. Running HAM Radio cables

    I've been struggling with running my radio cables through the wall. For many years I drilled some holes in the frame that held our cat door, but as you can see below, we stopped using the cat door. With the recent bout of horrible wildfire smoke here in Seattle I was forced to remove the cat door and hole up inside and was unable to use my radio. That prompted me to finally get up the courage to drill a hole in the wall of my house.

  8. Configure IC-7300 with HRD and SDRuno as a panadapater

    I have an MFJ-1788 Mag Loop antenna. I can tune it very easily by using my RSPdx to view the waveform. In the picture attached you'll notice that the antenna is tuned a little bit high for my current frequency. This makes it super easy to tune without worrying about having to put signal out on the antenna. But I kept having a problem where I was neglecting to change the frequency in SDRuno to match the one on my radio, and then inadvertently tuned the antenna to the wrong frequency. Attempting to transmit into that did not make my radio happy.

  9. Holder for new Pi Camera

    The creativity of 3D printing!

  10. 3D printed adapter

    Needed and adapter to connect my vacuum to my belt sander. Tada.

  11. Fixed the CNC mill...again

    One the disappointing aspects of doing your own CNC conversion is that you are the manufacturer. Need to know the limits of your machine? Go ahead and start running tests until something breaks. Rinse and repeat.

  12. Black and Decker Portable AC

    I recently picked up a Black and Decker Portable AC and wanted to port over a Blynk project I had created. I couldn't find anything online about what the infrared protocol is for the remote. So here you go:

  13. Nuclear cooling towers or tank stands

    These tanks are awfully tippy when connected to a Little Torch. Not so much anymore.

  14. TDR with the NanoVNA

    The performance of my satellite downlink station is nowhere near as good as I would like. I been doing some various troubleshooting measures to try and figure out what is going on. In my previous post, you can see some of my explorations about antenna tuning. In this post I took my first pass at exploring the feedline situation. It's been up for at least five years and wanted to make sure nothing untoward had happened to it.

  15. I cut it twice and it’s still too short!

    For my satellite ground station I built an antenna from the plans by WA5VJB

  16. abandoning Pi-Hole for cloudflared

    I've been using Pi-Hole for a while and it just caused too many problems. Many shopping carts across the web would just fail. I need to run google ad campaigns and you can't get to the admin UI. Therefore I decided to move dns resolving back to my ER-X and instead use cloudflared to resolve DNS queries so CenturyLink has a harder time selling my browsing history.

  17. Satellite Fun

    I’ve been slowly working towards building a satellite uplink and downlink station for years. I have finally reached a point where I finished building the station and have Receive some signals.

  18. Wrench Holder

    Seattle is due for a big earthquake. Our wrench for our water barrel and emergency gas cutoff was always going walkabout. I whipped up this little holder so it has a home to live on the back of our front door.

  19. Causal Inference Resources

    I was inspired by the post "Why you should stop worrying about deep learning and deepen your understanding of causality instead" to write up some of the resources I've used over the past year as I myself have tried to learn more about causality.

  20. Date Based Cohort Analysis for Adobe SiteCatalyst using R

    Over the years I've generally avoided Excel. Being a programmer, I could just pick up python and write code to do what I needed, I didn't need to hack something together in Excel. But I always ended up back there for the charting.

  21. The Lean Startup Movement from a Decision Science perspective

    First off, my apologies to actual Decision Scientists. I have no formal training and just recently learned that the area I'm fascinated by actually has a name.

  22. The Lean Startup Movement and the Quant Uprising

    I'm building my first new product in over a decade. I started my career back in 1993 as a black box tester on Media 100. I joined the team just as the first engineering prototypes were coming in from manufacturing, well prior to shipping v1.0. After that I helped create Adobe ImageStyler 1.0 in 1998, and then Adobe LiveMotion 1.0 in 2000.

  23. Recovery from CFS/Post Exercise Syndrome

    Back in my original post about my electric bike conversion I mentioned that I had CFS, aka Chronic Fatigue Syndrome. CFS is a poorly defined health condition that in my opinion actually covers a number of very different health conditions. I'm glad I never really accepted it as a diagnosis from the rheumatologist that mentioned it to me, but instead kept scouring my life and health for anything that could impact my energy level.

  24. Lean Startup Book Roundup

    Earlier this year I got involved with using Lean Startup techniques to help with a new business inside of Adobe. As is my normal style, I read a large number of books to help get my head around the techniques and build up a base of knowledge I could use in the future.

  25. Thoughts on flying the Cessna 162

    Yesterday I had a chance to fly the Cessna 162/Skycatcher. This isn't a review, just some thoughts on the experience. We just had almost 75 days straight of rain in Seattle. My drive to renton looked like: Joy; Despair; Joy; Despair; Joy as I drove through alternating spots of fog and sun. Luckily for me KRNT ended up in a spot of very clear skies centered around the Lake Young area. Pretty much everyone else looked socked in.

  26. Making Machinable Wax

    I recently converted my mini-mill to CNC and watching it run full speed with aluminum is a little terrifying. I thought having some machinable wax to play with while I learn would save me a lot of anxiety.

  27. Sunrise: 7am; Sunset: 4:45pm

    In preparation for short dark days, I decided to build a stand to mount my sunlamp in a better position.

  28. Winter Project?

    Hmm, just saw some discussion about a CNC router. I do have those CNC parts kicking around....

  29. 0.5 hours Pilot in Command

    How do you know someone is a pilot?

  30. Abandoned: CNC Mill

    I don't know about the rest of you, but I start a lot of projects that don't reach completion. I've become emotionally attached to the parts that I dragged around with me so I'm loathe to part with them, but I thought I would start documenting them.

  31. data geekery and tuning

    I finally finished my data acquisition for the bike. I used an Arduino with an SD Shield to capture the TTL serial data as output by the Cycle Analyst.

  32. eBike construction details

    I had a great time giving a talk at dorkbot-sea about my build. Lots of great questions.

  33. Complete!

    Instead of writing the blog, I went ahead and actually put together the bicycle.

  34. Parts Ordered

    After an obscene amount of time reading the forum at: I went ahead and ordered parts.

  35. Setback


  36. Mission

    Since I'm doing all the design on this bike, the number of choices is a little overwhelming. To clarify things, I decided to set the mission I'm trying to accomplish. This is a big thing in the private pilot world because everyone wants the big fast plane, but realistically you are better off choosing your mission and buying a plane to fit it.

  37. Electric Assisted Bike Legality in WA

    While I'm writing about the legal stuff first, that's actually the last thing I did.

  38. Lathe finished

    I finally finished the lathe conversion. It ended up being a lot more work than I expected as I ran into problems in pretty much every area.

  39. Lathe Remotoring

    Why did I decide that putting a new motor on my lathe was a good idea?

  40. EZ Build Engine Kit

    My fried Josh managed to find himself owning two lathes. After helping him resolve that problem I found myself an owner of a Jet 9x20 lathe. Not having used a lathe in about 10 years I decided to start by working on a skills building project.