Developer Francis Stokes discovered himself in want of a USB-UART adapter, and reasonably than look forward to supply opted to place one collectively — utilizing elements mendacity across the dwelling lab to create a “jank UART to USB cable.”
“My dwelling ‘lab’ is, sadly, a manifestation of the unwinnable, uphill battle in opposition to entropy. The most recent sufferer to the sprawl of boards, prototypes, and different miscellanea was my little Adafruit CP2104 USB to serial converter,” Stokes explains. “So far as I can inform, it has actually dropped off the face of the Earth.
“After all, the very first thing I did was hop on-line to order a brand new converter. Shortly thereafter, nevertheless, I got here to the sudden realisation that that is one thing I ought to be capable of make myself. I imply, what is the level in having a lab within the first place in the event you’re not going to make use of it for this type of factor! This can be a yak that merely must be shaved.”
When your industrial USB-UART bridge has gone lacking, it is time to get artistic. (📷: Francis Stokes)
Often of use in speaking with gadgets which lack their very own USB serial capabilities, USB-UART bridges present a TTL serial port when related to a machine’s USB port. Hook the opposite finish to a tool with its personal TTL serial port, and also you’re prepared to speak UART — both for debugging or for reprogramming. In case your desk actively eats your USB-UART adapter, although, issues turn out to be tougher — which is the place Stokes’ creation is available in.
“I occurred to have this outdated Arduino Duemilanove board simply laying round, gathering mud, which has an FT232RL chip from FTDI to transform serial UART to USB,” Stokes explains of the first supply of scavenged components for his home-brew UART adapter. “The very first thing I did was hearth up the hot-air rework station with the intention to de-solder the chip, together with the 2 capacitors simply above it.”
The FTDI USB-UART chip was salvaged from an outdated Arduino Duemilanove — the place, sadly, it was not socketed. (📷: Francis Stokes)
With the surface-mount chip in-hand, Stokes used an unpopulated SSOP4 breakout board — rigorously re-soldering the part utilizing a fine-tipped soldering iron — to supply a foundation for the adapter. A knife and a sacrificial USB cable supplied the USB finish of the equation, and a cautious take a look at FTDI’s information sheet for the half revealed precisely what wanted to be soldered the place.
“Discover the Kapton tape and sizzling glue mess,” Stokes says of the completed adapter. “That is actually there to re-enforce the flimsy solder connections, and to cease something from shorting in a while, nevertheless it undoubtedly helps with the scavenged look. So the jank cable was successful! I am nonetheless completely satisfied {that a} professionally made adapter is coming within the subsequent few days, however rattling if it would not really feel cool to know that I can whip up my very own instruments in a pinch.”
Stokes’ full write-up is obtainable on GitHub.
