I turned an old phone into a system monitor for my computer — and the results blew me away

Remote System manager
(Image credit: Future)

Chances are that Santa brought you or someone near you a shiny new phone, making your old model seem worthless once you've moved off all the data to your brand new handset. But that old phone can find new life with a new task — turn it into a remote system monitor that lets you peer inside a Windows computer to see that machine's vital stats.

I have an ulterior motive here. My computer’s balky fan whines then goes silent as the system’s temperature rises and gets out of control. I tried monitoring the fan speed and temperature in the system’s BIOS pages, but it doesn’t work while the computer’s in use nor does it show two parameters at once.

To solve this, I made a remote system monitor from an old phone that shows me what’s going on inside the computer at a granular level. This project doesn’t require tools and takes about 30 minutes, with the end result being enormous insight into a PC’s inner actions. Best of all, it cost me just $1.62. Let’s get started.

Finding the phone

(Image: © Future)

Chances are there’s an older phone sitting around your home. For me, the hardest part for me was finding my retired Pixel 6 handset. After digging it out of a drawer, dusting it off and plugging it in, I wiped its contents. With no SIM card, the phone will use Wi-Fi.

Setting up the PC server

(Image: © Future)

As the phone charged, I installed the Trigone Remote System Monitor (RSM) software onto my computer and created an account. It works as a data server with Windows 7, 8, 10 and 11. Sadly, there’s nothing for Macs, but there are several system monitor apps that show the data on the Mac’s screen.

The RSM server uses minimal system resources and wants to use port 19150. Its data flow is encrypted and the server certificate is usually automatically provided, but you might need to enter it manually.

Readying the phone

(Image: © Future)

The remote monitor will be a single purpose device so for safety’s sake, I turned off its camera and microphone. I took a trip to the Play Store and installed the $1.49 Trigone Android app. (Sales tax accounted for the rest of my expenses.)

Charging and viewing

(Image: © Future)

I finished the preliminaries by setting the phone up on a Samsung Fast Charge Qi stand. That accessory will not only wirelessly power the phone but hold it at a comfortable 45-degree angle under my system’s screen — perfect for at-a-glance viewing.

Creating the Dashboard

(Image: © Future)

With the phone ready for an onslaught of data, I configured the phone’s Remote System Monitor Dashboard to refresh the PC’s data every half-second; the interval can be as long as 10 seconds. After some trial and error, I chose to display the data in two horizontal rows of five items — any more, and the items would get too small to easily see. The dashboard runs in landscape or portrait mode.

Adding the data streams

(Image: © Future)

The selection of the data streams to monitor can be mind-numbing with more than 100 items available. I settled on nine key parameters including overlapping line graphs to show the all-important speed of the system’s fans as well as gauges showing processor temperature and load and hard drive capacity.

Arranging and adjusting the screen

(Image: © Future)

Nearly done, I customized the presentation by swiping right to open the app’s details screen and using RSM’s Arrange widgets feature. Here, I moved the all-important fan speed line graph into the upper left and doubled its size to make it more visible.

Keeping the screen active

(Image: © Future)

So far, so good, with the data flowing smoothly and the graphs updating in near real time. Unfortunately, the Pixel 6 wants to go into its lock screen after 30 minutes. A download of the free Screen Alive app solved this by letting me set it to keep the phone active for 10 hours at a time. Waking the screen up is one of the first things I do every morning.

Watching the data flow

(Image: © Future)

With the RSM screen set up, sitting underneath my PC’s display and live data updating every half-second, the view is beyond comparison. Confirming my fears, I could see that the system’s fan speed dipped causing the temperature to quickly rise. Clearly, a new fan was in order. After the replacement, the two fan speed line graphs are now as flat as last night’s beer.

Keeping tabs on your PC

The remote monitor is a valuable diagnostic tool that provides instant insight into the computer’s inner workings. For instance, I noticed that while I was watching a movie or gaming online, the system’s graphics power and processor load would more than double. This points to my next project: getting a graphics card to take some of the video load off the processor.

So far, the phone and RSM app have teamed up to faithfully show what’s up with my PC without letting me down. Be careful, though — I’ve found that it’s so good that watching the system’s operational ebb and flow can be addictive, taking my attention away from my work and play. Still, it’s a small price to pay for seeing what’s going on inside my computer.

More from Tom's Guide

Category
Arrow
Arrow
Back to Gaming Desktops
Brand
Arrow
Processor
Arrow
RAM
Arrow
Storage Size
Arrow
Colour
Arrow
Condition
Arrow
Price
Arrow
Any Price
Showing 10 of 137 deals
Filters
Arrow
Show more
Brian Nadel

Brian Nadel is a freelance writer and editor who specializes in technology reporting and reviewing. He works out of the suburban New York City area and has covered topics from nuclear power plants and Wi-Fi routers to cars and tablets. The former editor-in-chief of Mobile Computing and Communications, Nadel is the recipient of the TransPacific Writing Award.

Read more
Dell XPS 8940 review
How to turn your old PC into a storage server
Razer PC Remote Play running on a gaming laptop and streaming to a phone attached to the Razer Kishi Ultra mobile controller
I rarely stream PC games to my phone but Razer just convinced me with PC Remote Play
Google Pixel 9 Pro XL desktop mode.
I tried this hidden desktop mode on my Pixel 9 Pro XL — Google needs to bring this to all Android phones
How to build a PC
I just built an RTX 5090 gaming PC — here’s what I used and how to build your own
the OnePlus 12, iphone 16, iphone 16 pro, galaxy s24 ultra and pixel 9 pro fold
Selling your old phone? I worked in second-hand electronics stores and you need to avoid these 3 mistakes
Geekom Mini-PC with 4K TV on stand in living room
I tried using a Mini PC with a 4K OLED TV and the results surprised me
Latest in Computing
An image of a CAPTCHA
Hackers are using reCAPTCHA to trick users into infecting their own PCs with malware — how to stay safe
A smartphone screen displaying the Android name and logo next to a sign reading 'MALWARE'.
Fake Google Play Store pages are spreading Trojan malware that can steal your financial data
ExpressVPN connected on Linux app
ExpressVPN launches huge Linux update – what you need to know
MacBook Air M4
MacBook Air M4 just finally solved a keyboard problem after 25 years — here's what's fixed
Cartoon image of three people using smartphones and laptops
NordVPN reinforces its security credentials with independent audit
RTX 50 series GPUs
I was hyped for Nvidia's RTX 5060 Ti and RTX 5050 — until I saw these leaked specs
Latest in Features
A woman with dark curly hair holds her hand to her forehead in frustration because she cannot sleep at night due to too much light coming in her bedroom window
Trouble sleeping? 5 things in your bedroom that could be sabotaging your sleep
Robot looking at a laptop/Future AI generated image
I test AI chatbots for a living — 7 common glitches and what to do when they happen
A Rollei 35AF film camera
I’ve seen the future of film photography — 3 next-gen gadgets I'm excited about
A white Sigma BF camera
I just tried the one camera I’m most excited to test this year — and yes, it’s the Sigma BF
A woman wearing a grey sports bra sleeping on her front with arms overhead next to gym bag and skipping rope. Tom's Guide Sleep Week 2025 logo
I'm training for the London Marathon — here's how sleep makes you a better runner
A white Sigma BF camera
I tried 5 next-level cameras, from the Sigma BF to a cutting-edge drone — here's why they made me rethink photography
  • Math13
    In the app's general settings there is an option to keep the screen on. No need for an additional app. Furthermore, it allows to keep the screen on only when the phone is charging. So if you plug it to your computer, when your computer is turned off, if the USB doesn't provide power, the screen will turn off then it will automatically turn on and display the dashboard if you pin the app. Here is a tutorial: Qk9bl-BtOcMView: https://youtu.be/Qk9bl-BtOcM
    Reply