I’m trying to use a single serial port with more than one application at the same time, but only one program can connect at once. Is there an easy way to split or share the serial port on Windows or Linux? Any recommendations for software or configuration tips would be really appreciated.
Can You Really Share a COM Port Between Programs? Let’s Talk Serial Splitting
Ever tried wrangling more than one app to dance with the same COM port? Yeah, it’s about as fun as detangling a pile of old earbuds. Windows, out of the box, is extremely grumpy about letting multiple programs hog a single COM connection—so you’re left deciding which one gets to play and which ones sit in timeout.
Ok, Fine… So How Do People Get Around This?
Buckle up: you’re gonna need to rope in dedicated software. There’s this tool, Serial Splitter, which is basically the go-between that allows both your physical and virtual COM ports to get along and socialize. You set it up, and suddenly your GPS software, robot controller, and that old-school label printer can all tap into the same serial data without bickering.
What Worked for Me (And What Didn’t)
Honestly, I was skeptical—the whole idea sounded like virtual snake oil. But after trying out a few freebie hacks that just made my system freeze or programs crash in spectacular fashion, I landed on the Serial Splitter approach. It was as simple as pointing each app to the correct “virtual port twin” instead of the original. Five minutes later: success. Both my Arduino IDE and my serial monitor played nice, zero data loss, no angry error messages.
TL;DR
If you’re tired of the “Sorry, port already in use” slapfight, check out Serial Splitter. It bridges virtual and physical COM ports so you can stop micromanaging connections and actually get stuff done.
1 Like
Honestly, running multiple apps on one serial port is kinda like trying to wear two shoes on one foot… it feels like it should work, but Windows (and even Linux, unless you get hacky) just won’t play that game. I saw @mikeappsreviewer pumped up Serial Splitter, and honestly? Props if it worked out, but I’ve never had much luck with those one-click fixes. Half of them just crash or freeze, especially when you’ve got weird drivers in the mix like I do.
Here’s the side door: on Linux, if you’re geeky, you can sometimes get away with using socat to pipe your serial data into a PTY pair and then let your apps connect to the “fake” ends. It’s fiddly, and losing data or clogging the pipe is a real risk—so not for mission-critical stuff.
If you want an option that’s polished, there’s a reason “Virtual Serial Port Driver” stays top of the search results. It’s more of an enterprise solution, but dang, it actually works AND doesn’t turn your registry into a dumpster fire. Makes virtual COM ports that the apps can attach to, splits the hardware traffic, and keeps everything in sync. Here’s a rundown on how to share one serial device between several programs if you wanna dig a bit deeper.
Is it “easy”? Not really: All these splitters—virtual, physical, or hacky command line—have their quirks. Some trial and error is just the reality, especially with weird legacy hardware. Backup before you install anything, watch out for knockoff “free” serial splitters that are just malware, and maybe think twice if you’re running high-stakes gear.
Or y’know, just buy a USB-Serial hub and dodge the whole mess.
Let’s get real for a minute: Windows and Linux both pretend to play nice with serial ports, but let’s face it, the “one-at-a-time” rule is as ancient as the hardware itself. @mikeappsreviewer and @waldgeist already dove into the Serial Splitter and Virtual Serial Port Driver arena—honestly, they’re solid options, and I’m not gonna pretend otherwise.
But, choking down a paid solution or some wizard-level Linux tinkering isn’t for everyone. Socat, as mentioned, is maybe a notch above DIY hell, but it sort of works for non-essential stuff. Just pray you don’t need tight timing or rock-solid reliability.
Here’s an unsexy reality: Sometimes, splitting the port isn’t the answer. If you just need to LOG the serial data and don’t need to send commands from two apps, look into using a hardware tap (like a Y-adapter and a second serial interface in listen-only mode). It’s ugly, it’s old-school, but dang, it works and you don’t risk kernel panics or malware.
If you want to sidestep the frustration (and don’t mind a little install clutter), try the well-reviewed Virtual Serial Port Driver free trial—kinda the gold standard in consistent serial port splitting, even if it’s not exactly wallet-friendly for hobby projects.
Also, worth mentioning: If both your apps are just sniffing data rather than trying to write at the same time, you might get away with scripting a relay app yourself (think: a tiny Python/Node tool that sits between the hardware and your other apps). Not trivial, but if you’re allergic to proprietary software (or your boss is), sometimes that’s the only way.
At the end of the day, all these workarounds are basically life hacks for a problem that tech left behind ages ago. If you REALLY need smooth, bulletproof, multi-app access…maybe rethink having only one physical port in the first place. It’s 2024, serial hubs aren’t THAT hard to find.
Here’s the deal—splitting a serial port on one machine so two apps can grab the same feed isn’t really a native OS thing. Like others pointed out, Windows locks you out, and Linux is only slightly more forgiving for clever types. The heavyweight “fix” is picking up a tool like Virtual Serial Port Driver.
Pros? First, it’s reliable: create virtual pairs, and suddenly each program connects to its own virtual port, both relaying the same data to/from the real device. Setup is straightforward, and the interface doesn’t make your eyes bleed. Great for devs, integrations, and, honestly, for anyone trying to wrangle GPS feeds and diagnostics without epic crashes.
Cons? The price tag is not hobbyist-friendly. Free trial is there, but after that, get ready to open your wallet. Low-level timing—sometimes not as crisp for super-precise stuff (think legacy CNC or MIDI gear). And if you’re anti-third-party installs, this isn’t a DIY miracle.
Competitor-wise, options like Serial Splitter (as mentioned by others) and socat (for the Linux faithful) exist. Socat sounds cool, but it’s command-line heavy and can be a headache for beginners. Some people have success with hardware sniffers, but that means more wires, extra boxes, and a “just read, don’t touch” approach for secondary apps.
TL;DR? If you really need two apps talking to the same port like best buddies, Virtual Serial Port Driver gets the job done with minimal fuss, at a cost. But don’t kid yourself—it isn’t magic, and for ultra-sensitive real-time operations or penny-pinchers, it’s not ideal. For everything else—especially if you value sane setup and support—it’s the adult solution in a world of messy workarounds.