ASIair PLUS Review : Is the WiFi Really Better?

My evaluation of the ASIair PLUS continues. We are still experiencing cloudy nights down here, so I decided to focus on someting I can test without seeing the sky: WiFi performance. I've read/watched a number of other reviews and everyone agrees the PLUS performs well. But I wanted to dig a little deeper, so I set up an experiment to quantify the WiFi performance of the ASIair PLUS and compare it to the ASIair PRO. Here's how I approached it.

Test Design

The testing focused on measuring signal strength between the access device (iPad or home WiFi base station) and each model of ASIair. The goal was to see how much improvement the new PLUS model shows over the previous model.

Disclaimer: This test wasn't designed to be scientifically rigorous. Ideally, I would have repeated the measurements multiple times and averaged the results. It would have been nice to measure data throughput changes at various distances, too. Still, I think this test design is adequate to get a feel for how much improvement the PLUS brings over the PRO.

The Direct Connection Test

My plan to test the performance of the direct connect mode was pretty simple. I would place both ASIair models on a table, power them up, and measure their signal strength at varying distances.

To take my measurements, I used an app called WiFi Explorer. WiFi Explorer is designed to discover, monitor, and troubleshoot wireless networks. It proved a convenient way to collect the signal strength data I needed for my tests.

Both ASIair's were configured to use the 2.4Ghz range. To avoid having them interfere with each other too much, each used a different channel (see Figure 1).

Figure 1: Each ASIair was configured to use a different part of the spectrum.

The Station Mode Test

I also wanted to test Station Mode. That's what ZWO calls the configuration that has the ASIair connect to your iPad through your home WiFi network instead of directly. This is a very convenient way to run an imaging session if you're doing it at home. Why sit out in the yard in the cold when you can control things from inside your nice, warm house? My previous experience told me that ASIair PRO's ability send WiFi signal through walls was pretty poor, so I wanted to find a way to compare it to the PLUS.

I accomplished that by placing both ASIair units outside where I normally set up my telescope, and measuring their signal strength at the WiFi access point inside my house.

Taking Measurements

The measurement process for the direct connection experiment was straightforward. First, I marked out a series of measurement points at 15-foot intervals. Next, I carried my MacBook (running WiFi Explorer) to each point and took a signal strength reading. I stopped measuring at 150 feet and plotted the results.

Measuring station mode performance was even easier. Read on to see the results of both tests.

Duelling Astro-Controllers

Results

Ok, this is the part you really want to hear, right? The bottom line is that The ASIair PLUS performed significantly better than the PRO at all distances.

Direct Mode

The first set of results is from my simulation of a direct connection to the ASIair. Measurements were taken using a MacBook and WiFi Explorer instead of an iPad. The results are shown in this chart (see Figure 2).

Figure 2: Signal Strength measured over increasing distances.

As you can see in Figure 2, the ASIair PLUS maintains a fairly constant advantage over the PRO at every distance measured. My anecdotal experience backs this up. I found that I could walk much farther away with my iPad during an imaging session without losing the connection to the ASIair PLUS.

I wanted to quantify how much better the PLUS is than the PRO. While the signal measured varied quite a bit in my tests, when I took an average of all the measurements, the ASIair PLUS showed a 110% improvement in signal strength over the PRO. Impressive.

What about Station Mode?

We know that ASIair PLUS outshines the PRO for a direct connection while outdoors, but what about station mode? This chart (Figure 3) taken directly from the WiFi Explorer screen shows how much signal each unit delivered into the house.

Figure 3: Signal strength measured at the house's access point.

The ASIair PRO clearly has a much harder time sending its signal through a wall. It's easy to see why I had so much trouble using station mode with the ASIair PRO. The signal from the PRO was just too attenuated after traveling from the telescope location and through the walls. The signal from the PLUS was also attenuated, however, it remained strong enough to be usable. No more and stringing a long ethernet cable outside for me.

Conclusion

Based on what I saw in these tests, the WiFi performance of the ASIair PLUS is consistently better than that of the PRO. Of course, that's what we expected from the PLUS with its external antenna, but it's reassuring to see the expectation backed up with real data. The extended range in Direct Mode will help when you're out in the field and don't want to stay right next to your rig. For example, it can get pretty cold when imaging at a dark site in the desert here in Southern California. It's nice to take refuge in the car and still be able to monitor the session. This wasn't always possible with the PRO. The PLUS gives you more options.

The ASIair PLUS will give you more options for where to place your. Rig when doing back yard imaging too. In my case, having the scope far enough away from the house to polar align on Polaris put it a bit too far away for the ASIair PRO to connect reliably. With the PLUS, I can image from that location without any problem.

With its small size, extra features, and 110% better WiFi signal, I call the ASIair PLUS a real winner. Recommended!

ASIair PLUS Review : First Impressions

Introduction

When the latest evolution in my astronomy hobby took me down the path towards astrophotography, I discovered there was a lot to learn. Fortunately, I found a product that made the transition much easier — the ASIair PRO. Soon I had upgraded my rig to include a cooled astronomy camera, electronic focuser, and automatic filter wheel with the ASIair PRO taking care of all the details involved in managing those things. 

The one complaint I had about the little device was the WiFi connectivity. The range was too short, and the connection would often drop. So when I saw that a new version was coming out, I jumped at the chance to upgrade.

TL;DR

Rating: *****

Summary: The ASIair PLUS represents a significant step forward for ZWO’s handy little astro controller line. It adds several refinements that are both well thought out and well executed.  

Pricing: $299

Features: Improved WiFi connectivity, Better Power Management, Improved Reliability, (slightly) Smaller & Lighter

Pros: Inexpensive, Easy to Use, Supported most Mounts, Actively supported & improved via software updates

Cons: Supported only ZWO cameras & Focusers, Less flexible than a PC, Less than stellar documentation

Best for beginning and intermediate astrophotographers that want to take the complexity out of image acquisition to focus on the art and science.

Experience Officer Programme

After pre-ordering an ASIair PLUS from a dealer, I heard out about ZWO’s ASIair PLUS “Experience Officers” program. This is ZWO’s way of getting early feedback from current ASIair PRO users willing to test and review the new model. So I signed right up and got busy making a test plan. 

What's in the Box

The ASIair come with everything you need to get started. Well, nearly everything. In the box you’ll find the ASIair PRO itself, a dovetail mount, a USB3 cable, a few DC power cords for hooking up accessories, and a Quick Start guide. If you already have a 12 volt 5 amp power supply, you’re ready to go. If not, make sure to add one to your order so you won’t be disappointed when the unit arrives.

What’s in the Box

New Features

The astronomer’s curse (i.e. cloudy skies that appear whenever you get a new toy to play with) delayed my detailed testing. On top of that, I had to send my mount in for repairs, so I decided to focus this review on my first impressions and followup with a more detailed review in the coming weeks. 

Better WiFi

The most obvious improvement in the ASIair PRO is the external WiFi antenna. It supports both 2.4Ghz and 5Ghz WiFi bands like the PRO, but promises to deliver a lot more range than before. 

As I mentioned earlier, my chief complaint about the PRO was the WiFi range. It worked fine when sitting next to the telescope, but the range was so short that wandering away just a few yards caused the connection to my iPad to drop. My dream of monitoring astrophotography sessions while sitting in the house was not to be realized. 

I tried a few of things to solve the problem. First up was one of the battery-powered WiFi extenders others had recommended. It extended the range somewhat, but its range was still too short and the connection kept dropping.

The solution that worked best was running an ethernet cable from the house out to the ASIair PRO. I used that setup for a while, but it was inconvenient. 

Next, I connected the ASIair PRO to an old Apple AirPort Express I had lying around. The AirPort Express connected to the house WiFi network, so I didn’t have to string out an ethernet cable. That worked pretty well, but it still bothered me that I couldn’t use the WiFi built in to the ASIair. I was eager to get my hands on the PLUS and test the WiFi Performance.

External WiFi Antenna

As soon as I got it configured, I connected my iPad directly to the ASIair (not via the home network) and walked away. The further I walked, the bigger the smile on my face grew. I was about 70 feet away when I finally lost the connection, and there was a wall between the iPad and the ASIair PLUS. That would have been impossible with the ASIair PRO.

Better Power Management

Less obvious are the improvements ZWO made in power management. There’s a hint of something new on the outside of the ASIair PLUS, though. If you look closely, above each of the 4 outgoing power ports is a small LED. Now, you can tell at a glance which port is supplying power. Using the PRO, I would sometimes forget which port I had turned on and plug something (like a flat panel) into an unpowered port. Not a big deal, but it’s nice to have the visual clue to avoid making that mistake. The real difference, though, can only be seen through the app.

Now, in addition to controlling which port is on, and which is off, you can see much power is being delivered to accessories.

Power Port Configuration

Power Monitoring

Better Reliability

The PRO stored its operating system on a removable microSD card. You could choose to store images on the same card too, but that’s probably a bad idea. It’s not uncommon for microSD cards to fail, and if the one holding your operating system stops working, you’d better hope you made a backup like the manual told you to!

Rather than relying on a microSD card, the PLUS stores its operating system internally. Images can also be stored on the internal eMMC drive, however you can still add a microSD card to store images if you prefer. There’s also a USB-C port that you can plug an external hard drive into if you need more capacity. 

I copy data out of the ASIair PLUS after each imaging session, so I don’t have a need for an external hard drive. However, I am using a microSD card to store images. That way, the operating system gets to keep the internal storage all to itself — which makes me feel safer. 

Getting data out of the ASIair PLUS and onto my Mac for processing is easy enough. With the ASIair connected to my home network, it appears as a like any other computer. I just copy the data over the network using Finder (or File Explorer if I had a Windows PC).

Smaller and Lighter

As a final touch, the folks at ZWO made the PLUS a little smaller and lighter than its older brother, the PRO. According to ZWO, it’s 24% thinner and 13% lighter.While it’s true the PLUS is thinner, it’s also a longer and (a tiny bit) wider than the PRO. It seems ZWO focused on reducing the thickness, which is probably a good idea. Making it thinner will provide even more clearance for people who want to mount the unit between the telescope and its mounting plate. For me, It makes no real difference, since I mounted mine on the ProAstroGear Black-CAT mount. 

Conclusion

So far, I’m very impressed with the ASIair PLUS. The increased range provided by the external WiFi antenna was immediately apparent. I had the kind of experience we all like to have with a new piece of gear — it didn’t disappoint. From the initial setup and activation to the installation and initial operation, it did exactly what it was supposed to do. The power management interface is nicely implemented and will be very useful while running a long imaging session.  

Is it worth the money? If you don’t already have the preceding model, definitely. If you already have the PRO, the answer will depend on how much you value the new features. For me, the improved WiFi alone is worth the price, and you can always defray some of the cost by selling your old PRO model.

Bottom line: I recommend it to anyone just starting out that wants to grow their involvement in the hobby. The ASIair makes it easy — well easier — to get some serious astrophotography done.