Hacking USB Serial Port Adapters

September 23, 2009 by 16 Comments

keyspan_all (Custom)

The folks at Openschemes.com have written up an article on how to convert a USB serial port adapter to a low voltage serial interface for interfacing with microcontrollers. Though you can always just buy one, this is a fairly quick and cheap solution, especially if you are in a pinch or don’t have access to a retailer. The specific models you should watch for, are the ones with two chips, a microcontroller and a line translater.They go through the process of finding exactly where to patch in to add an extra interface. It only takes a couple wires and you are ready to go.

Not only can you use this as your serial connection to another microcontroller, but you can actually take control of the one on the board itself. If you load it with the drivers from TI, you gain access to the flash memory and can do whatever you want. They don’t go into much detail here though, stating that they’ll write another article on that.

We thought this little bugger looked familiar so we went digging through our archives.  Sure enough, we found this system in action back in January of 2008.

[via Hacked Gadgets]

How-to: USB Remote Control Receiver

October 30, 2008 by 126 Comments

Now that we listen to MP3s, and watch XVIDs or x264s, a computer is the entertainment center in at least one room of most homes. Unless you have a special HTPC, though, you’re probably stuck using the keyboard to pause, change the volume, and fast-forward through annoying Mythbusters recaps. PC remote control receivers range from ancient serial port designs (who has one?) to USB devices not supported by popular software. In this how-to we design a USB infrared receiver that imitates a common protocol supported by software for Windows, Linux, and Mac. We’ve got a full guide to the protocol plus schematics and a parts list.

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RS-232 USB Madness

April 8, 2007 by 15 Comments


If you’ve been amused by the lengths people go through to speak to a serial device these days. [timmeh] just took the cake. He build his own frikkin’ tiny RS-232 to USB interface with the diminutive SIL CP2101. The package on it is QFN-28 (If PLCC is Darth Vader, QFN-28 is his mean little brother.) That said, if you prefer to work with stuff that talks TTL or RS-232, this could be a handy add-on to pop a USB port on your project. (Oh, look, they have samples…) Sure, we’ve beaten the serial connections to death, but they’re so handy we just can’t resist. It may be a decent way to add a serial port to your laptop. (Picture this: dell’s bluetooth cards are usb devices – you could add one of these without even voiding your warranty.)

Break Me Off A Piece Of That Open Source Serial Adapter

December 25, 2024 by 12 Comments

We know, you’ve already got a USB to serial adapter. Probably several of them, in fact. But that doesn’t mean you couldn’t use one more — especially when it’s as as cleverly designed as this one from [Anders Nielsen].

The first thing you notice about this adapter, and the big departure from the ones that are likely littering your parts bin, is that it terminates in a full-size male DSUB9 connector. With the ability to be directly plugged into a RS-232 port, this adapter will certainly catch the eye of retrocomputer enthusiasts. With a clever arrangement of jumpers, you can even reconfigure the RX and TX lines to be straight-through or cross over as needed.

But if you’re working with something that doesn’t have a literal serial port, no worries. All of the lines coming from the CH340G chip are broken out to a header so you can connect it up to whatever device you’re working with via jumpers.

In fact, if you’re really sure you’ll never need that RS232 feature, the PCB is even designed in such a way that you can simply snap it off. Admittedly it might seem a little odd to get a device like this if you didn’t want that capability. But once broken off, it’s not like the components go to waste. [Anders] has designed the board in such a way that if you flip it over and install a right-angle header, you can use the RS232 segment on a breadboard.

But the list of features doesn’t stop there. There’s also a 3.3 V regulator on board that you can use to power external circuits, as well as breakouts for the data lines in the USB-C connector. In keeping with the theme of the device, that part of the PCB can also be snapped off if you want to use it elsewhere.

Most folks probably’ won’t need all the capabilities offered by this particular serial adapter, and that’s fine. We’re still happy that it’s out in the wild and available for the community to use and adapt as an open source project.

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It’s Remotely Ham Radio

December 11, 2024 by 33 Comments

Have you ever considered running your ham radio remotely? It has been feasible for years but not always easy. Recently, I realized that most of the pieces you need to get on the air remotely are commonplace, so I decided to take the plunge. I won’t give step-by-step instructions because your radio, computer setup, and goals are probably different from mine. But I will give you a general outline of what you can do.

I’m fortunate enough to have a sizeable freestanding shop in my backyard. When I had it built, I thought it was huge. Now, not so much. The little space is crammed with test equipment, soldering gear, laser cutters, drill presses, and 3D printers. I’ve been a ham for decades, but I didn’t have room for the radios, nor did I have an antenna up. But a few months ago, I made space, set some radios up, strung out a piece of wire, and got back on the air. I had so much fun I decided it was time to buy a new radio. But I didn’t want to have to go out to the shop (or the lab, as I like to call it) just to relax with some radio time.

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I2C For Hackers: The Basics

August 7, 2024 by 51 Comments

You only really need two data wires to transfer a ton of data. Standards like UART, USB2, I2C, SPI, PS/2, CAN, RS232, SWD (an interface to program MCUs), RS485, DMX, and many others, all are a testament to that. In particular, I2C is such a powerful standard, it’s nigh omnipresent – if you were to somehow develop an allergy to I2C, you would die.

Chances are, whatever device you’re using right now, there’s multiple I2C buses actively involved in you reading this article. Your phone’s touchscreen is likely to use I2C, so is your laptop touchpad, most display standards use I2C, and power management chips are connected over I2C more often than not, so you’re covered even if you’re reading this on a Raspberry Pi! Basically everything “smart” has an I2C port, and if it doesn’t, you can likely imitate it with just two GPIOs.

If you’re building a cool board with a MCU, you should likely plan for having an I2C interface exposed. With it, you can add an LCD screen with a respectable resolution or a LED matrix, or a GPS module, a full-sized keyboard or a touchpad, a gesture sensor, or a 9 degree of freedom IMU – Inertial Measurement Unit, like a accelerometer+compass+gyroscope combination. A small I2C chip can help you get more GPIOs for your MCU or CPU, or a multi-channel motor driver, or a thermal camera, or a heap of flash memory; if you’re adding some sort of cool chip onto your board, it likely has an I2C interface to let you fine-tune its fancy bits.

As usual, you might have heard of I2C, and we sure keep talking about it on Hackaday! There’s a good few long-form articles about it too, both general summaries and cool tech highlights; this article is here to fill into some gaps and make implicit knowledge explicit, making sure you’re not missing out on everything that I2C offers and requires you to know!

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Dial-Up Is Still, Just Barely, A Thing

March 6, 2024 by 97 Comments

In an era dominated by broadband and wireless cellular networks, it might come as a surprise to many that dial-up internet services still exist in the United States. This persistence is not a mere relic of nostalgia — but a testament to the diverse and uneven nature of internet infrastructure across the country.

Yes, dial-up internet, with those screechy, crackly tones, remains a useful tool in areas where modern, high-speed internet services are either unaffordable or unavailable. Subscriber numbers are tiny, but some plough on and access the Internet by the old ways, not the new.

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