Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Building the worlds jankiest serial to USB cable from scavenged parts

github.com

Post reply on HN
Print view View original

31–36 of 36 posts

Re: Building the worlds jankiest serial to USB cable from scavenged parts

#31

Post by tssva »

acadapter wrote: post #16

A small STM32 and libopencm3's USB stack would be a more flexible choice. You could for example set your own name, PID/VID, etc. With some clever setup of descriptors, you could even have multiple UART serials to one USB connection.

I think the point was to make something in a pinch with what was already available versus making the most flexible choice.

That being said I use, I'm not the author, https://github.com/Noltari/pico-uart-bridge to turn a Raspberry Pi Pico into a USB to dual UART adapter. It appears as a CDC-ACM device so is supported under Linux and Windows without any 3rd party drivers. I replaced my MacBook Pro with a Thinkpad years ago so I have no idea what the situation is on macOS.

Re: Building the worlds jankiest serial to USB cable from scavenged parts

#32

Post by ta988 »

acadapter wrote: post #16

A small STM32 and libopencm3's USB stack would be a more flexible choice. You could for example set your own name, PID/VID, etc. With some clever setup of descriptors, you could even have multiple UART serials to one USB connection.

Or a $4 RP2040 board.

Re: Building the worlds jankiest serial to USB cable from scavenged parts

#34

Post by programmer_dude »

f1shy wrote: post #27
unwind wrote: post #7

I thought this was a fun journey through a tiny DIY tooling project, and I enjoyed it! I liked the detail level which is turned up quite high, taking care to explain many of the steps that are (typically) taken for granted by electronics hobbyists. Still, this part stuck with me so I feel a need to comment: The high level overview is that "serial", or UART (Universal Asynchronous Receive and Transmit) is a protocol f…

Actually synchronous in this context has nothing to do with clock. It refers to the fact that the data does not come at regular intervals (synchronous), but asynchronously.

(A)Synchronous is a term of art. It precisely means what the GP said. Data can also not come at regular intervals for a synchronous setup.

Re: Building the worlds jankiest serial to USB cable from scavenged parts

#35

Post by osamagirl69 »

fstokesman wrote: post #17
snvzz wrote: post #5

Earlier quoted context omitted.

On top of that, it's enough to assert the microcontroller's reset to then freely use the RX/TX pins from the FTDI as if it wasn't there. Just plain insanity. As for cp2104 usb to ttl serial, full adapters using that chip cost $2 a pop on AliExpress. As the prices are like that, I ordered a few of every available usb-serial chip at some point. I'll be fine for a long time.

Indeed - I know I could have also popped out the DIP micro on the board and used it directly, but I choose not to for two reasons: 1. Its so much bulkier, and I wanted something that was the same form factor as my old unit 2. It seemed way more fun to do things this way, and I was pretty sure I could do the whole operation in less than an hour

Clearly you should have compromised and hacksaw'ed out the usb jack + ftdi region of the board, thus satisfying both your desire to have something jankey and compact. You would even get free activity LEDs!

Re: Building the worlds jankiest serial to USB cable from scavenged parts

#36

Post by ComputerGuru »

fstokesman wrote: post #14
unwind wrote: post #7

I thought this was a fun journey through a tiny DIY tooling project, and I enjoyed it! I liked the detail level which is turned up quite high, taking care to explain many of the steps that are (typically) taken for granted by electronics hobbyists. Still, this part stuck with me so I feel a need to comment: The high level overview is that "serial", or UART (Universal Asynchronous Receive and Transmit) is a protocol f…

You're absolutely right, I don't know why I had attributed the name to the full duplex nature. And of course, there is also USART, where you can have a separate clock line, which allows you to omit the start and stop bits too. At that point, you're essentially turning your UART into a single connection SPI bus.

I miss USART.
Post reply on HN