A look at UL/ETL Certification and Home Automation

Ever since I can remember, my dad has told me that any piece of electrical equipment that has a cord or is hardwired should be Underwriters Laboratories listed. UL listing means that a sample of the product has undergone testing and meets certain criteria for the type of device it is. Does this mean that items that lack the UL listing aren't safe? No, it could just mean that the company didn't spend the money to get the product tested.

Most things you buy with a cord are UL listed, so it really isn't a concern. However, with more and more products coming direct from overseas and being developed faster and cheaper, it is becoming more common to see mass market products lacking UL listing.

Taking a slight detour here, UL has been the predominant testing lab/certification and the one that most people recognize. However, recently more products bear the ETL mark. Edison Testing Laboratory was started by none other than Thomas Edison and performs similar functions to UL. I've done a bit of research and the only real difference is which service a company choses to use. ETL tests to the same standard as UL. I suspect there could be a cost or time to test difference between the two.

I've been very cautious about things I buy direct from overseas and even some things I buy here that aren't from mainstream manufacturers. While a UL or ETL mark doesn't guarantee that something is going to be safe, it gives me some reassurance that an independent lab has looked at the product.

When I went to purchase a 3D printer, the Creality Ender 3 Pro was advertised as having a UL listed power supply (older ones didn't). This got me curious about what that meant. Components of products can be UL listed without the entire product being listed; for whatever reason the whole device didn't go through certification. These components bear a different mark called a "listed component".

So while the power supply on the printer is UL listed, the printer itself is not. I'm not overly concerned about this as the power supply is the piece that connects to 120 V and outputs low voltage. This, of course, doesn't mean that the printer couldn't catch fire (I've seen reports of this).

For my son's Eagle Scout project, he's building something (I'll post about it when it is complete) that plugs into the wall and is controlled by a low voltage circuit. We found an example of what he wants to do on GitHub where the author posted a list of components. One of the components is a solid state relay that takes line voltage (120V) on one side and is controlled by low voltage on the other. While relays are quite common, mixing low and line voltage can be dangerous. According to the National Electric Code any time low voltage and line voltage are placed in the same electrical box, there must be a plastic separator between the two. When we remodeled our house, I had to find electrical boxes that had separators as I put low voltage audio controls in every room next to the bank of light switches.

Looking at this relay, I didn't see a UL component mark on it and even if I did, I'd be concerned about putting it in a box that had line voltage and low voltage. So in my effort to help my son (adults can help on projects and he's asked me to handle the electrical part and some of the electronics due to my knowledge of the field), I started researching parts that are UL or ETL certified so that we didn't have to worry about mixing line voltage and low voltage. The pieces we're looking at are widely used in IoT devices and consist of an outlet that can be controlled by a low voltage circuit.

I've looked and looked and have found some standalone outlets that are listed. I came across a blog post talking about the Sonoff smart plugs that are UL listed. Excellent, I may have found what I needed. I purchased 2 of the plugs and received them last week. They didn't have an ETL logo on them, but did have a UL logo on them. Unfortunately looking up the product in the UL database didn't come up with anything, but it did appear in the ETL database. When I asked Sonoff about this, they said that the S31 was ETL certified and not UL listed. That's kind of odd and the discrepancy is enough for me to send them back. I did, however, find another outlet TGWF115PQM by Top Greener that is UL listed (and is in the UL database). In addition, this plug was easily flashed with the Tasmota firmware that works with Home Assistant and I believe it will work for my son's project.

Many of the major brands of IoT devices, including the Belkin plugs don't list UL or ETL certification on their web pages. If they are listed, I think that would be an important fact to mention on their site. If you browse Amazon for smart plugs, you'll see some say CE or FCC certification; this is NOT the same as UL or ETL certification. Even if they say ETL or UL listed, I'd strongly encourage people to lookup the products and verify the certifications at UL or ETL.

If you're in the market for IoT devices, look carefully at the certification on the devices and would not order anything direct from overseas that is line voltage (I ordered a small computer last year direct and the external power supply was not UL listed so I just swapped it with another one that I had just to be on the safe side).

Stay tuned for more on the project and the journey.

Ryobi 18V ONE+ HP Compact Brushless Drill and Impact Driver Review

I've written a number of times about how much I like my Ryobi tools. This summer one of my small 1.5 Ah batteries died, so I looked at getting new ones. While many people prefer the larger batteries that last longer, my projects typically are short and don't require a lot of power. The small batteries are lighter and make the tools easier to use. Home Depot (the exclusive seller of Ryobi products), has a version of 1.5 Ah batteries that don't have a fuel gauge on them; to me, this makes the batteries pretty useless. There are a number of sellers on eBay selling the 1.5 Ah batteries with the gauges for about $30 per battery.

I saw that Ryobi released new HP brushless tools including a drill/driver kit with 2 1.5 Ah batteries that have fuel gauges! The cost, however, is $180 meaning the driver and drill are about $120. As I already have a perfectly good drill and driver, it was hard to justify.

For the holidays, I saw that Home Depot discounted the set by $40 bringing the cost to a bit more reasonable $140. I still didn't need the set, but the new tools are lighter than my current ones and potentially more powerful than the ones that I bought many, many years ago. I couldn't help myself and hit the buy button!

The tools arrived last week and the batteries are smaller and slightly lighter than my existing 1.5 Ah battery and have a sleeker design. The new impact driver weighs 842 g (without battery) and the drill 952 g vs 1192 g and 1226 g respectively for my old set (I have an even older drill that weighs 1420 g). The battery is 410 g vs 446 g for the 1.5 Ah battery. The weight differences are huge!

Left is the oldest drill/driver; middle was the one I bought a few years ago and the one on the right is the latest brushless drill/driver

Left is old impact driver; right is new impact driver.

I've used both tools briefly and they perform well. Are they better than the older tools? Maybe marginally, but it is hard for me to tell. I've seen a video where the person compared the new brushless drill/driver with the old brushless driver and found it less powerful (he had some odd results depending on the type of battery he used). Am I going to notice? I will definitely notice the weight difference, but probably not the performance.

Pros

• Brushless motors
• Lighter than what I already had

Cons

• May not provide better performance (depending on what you already have)

Summary
If you have existing tools that work, it is really hard to justify these new HP brushless drill/driver. Having extra batteries is always good and the lighter ones are well worth it for me. If the tools last as long as my old ones, then this will be an excellent purchase.

I was impressed enough with the set that I purchased the combo set for my dad. He has been using a 12V DeWalt drill for ages that is starting to fail. He likes the lightweight tools and I hope that he can get as excited for the Ryobi tools as I am.

Debugging Firebase Analytics on iOS

Once again I've been instructed to add analytics into an app. Anyone that has ever instrumented analytics knows that it is a royal pain as analytics requires various pieces of information in all kinds of places in apps. While there are ways to mitigate the number of places that code has to be modified, someone still needs to verify that the required events are fired and the necessary parameters are included.

Like many analytics systems, Firebase batches events and sends them off to the server every so often making it hard to see in real time what events are being fired. In order to facilitate analytics verification, Firebase has a method to enable near real time events. Unfortunately this requires access to the source as the parameter Google says to add is a runtime parameter (-FIRDebugEnabled). I was also told to look at an article about debugging, but clearly the author never actually tried the method described on iOS as it references the runtime parameter which is NOT available in TestFlight builds.

Just to make sure I wasn't crazy that there was no documented way to enable debugging in a TestFlight build, I asked a friend to review the documentation. He confirmed what I thought, but pointed out the following:

This behavior persists until you explicitly disable Debug mode by specifying the following command line argument: