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USB to RS232

s1buell

Does anyone here have any experience with this topic?

 

I`m going from a TUSB2077APTRTUSB2077APTR controller to two FT232RL-REELFT232RL-REEL IC`s just to test this prototype idea.

  • in reply to s1buell

    Hello Tom,

     

    I haven't used Atmel ARMs for a very long time - I did one project which was successful with a pretty early part (pre- Cortex) but I wasn't thrilled with the support at the time.

     

    I moved over to ST ARM based micros more than 10 years ago and I haven't seen any reason to change.

     

    On a board like this the cost of the processor is trivial - why not use something like an STM32F407 or even an STMH7xx part (400MHz, lots of RAM, 16bit ADC etc etc.)

     

    It looks as if your IO goes direct to the processor - OK for playing but no good for real life in industrial settings.

     

    I have a vague plan for a board for my own use - I'm a bit busy right now but I'll try to set down a few notes and we can see if there is any common ground.

     

    MK

  • in reply to s1buell

    Hi Tom,

     

    Is it for production, or for others to self-assemble? The QFN package may be hard for others.

    It definitely needs some isolation, which could be done using (say) opto-isolators or relays. The board I'm working on is constrained in size, so it's only got two inputs and two outputs (using opto and relays in this case), but it's got an option to attach another board. It's described here at high-level, but full details and BoM will be published at some stage. It uses a Pi i.e. Cortex-A, and has the advantages and disadvantages of that, there's a market for Cortex-M controllers as you've noticed too.

  •  

    The first CPU project is just a project to test the CPU, create firmware etc. Its my first go at a cpu so I started with the basics (Just to play)

    The mian issue we are having now is the firmware. I`ve ordered a Atmel-ICE to start this part.

     

    I actually picked this processor mainly to work with circiut python and onboard memory storage. No more compiling. But the target was to make the CPU easy to program and for operations people to have access to the last code used (hence circuit python)

    https://en.wikipedia.org/wiki/CircuitPython

    https://github.com/adafruit/circuitpython

     

    image

     

    And the application of this unit will be more for IIOT sensor reading with long range data transmission.

    The STM32F407/417 looks is really nice! The price is also good $11.06000 Digikey. I will put this on my radar.

    • I have a ton of questions but need to do some reading on the cpu first.

     

    In the end it will be for production (If no one cancels the project.....again lol)

     

    Size is important but not a constraint for us (smaller the better). Im going to use 20pin connectors to allow for any type of expantion board to be added

     

    Here a picture of the concept:

    These have a two channel DAC to allow for 4-20ma boards to be added (concept picture only). Well its an actual PCB but untested.

     

    image

     

    Shabaz

     

    BTW love the project!!!!!   (https://www.element14.com/community/external-link.jspa?url=https%3A%2F%2Fmedium.com%2F%40shabaz_yousaf%2Fviki-an-open-so… )

     

    I would be interested in producing and playing with this project....

     

    We use a PI addon boad to connect to the PI`s only for reading sensors and a little control if needed (basic stuff)

     

    T

  • in reply to s1buell

    Hi Tom,

     

    That makes sense, the dual-module approach looks neat.

    Also, it's great to hear you find the VIKI project interesting. it should just be a matter of weeks and then we'll hopefully have the documentation, BoM, etc published.

  • Tom, cool problem. Because everybody has thrown there 2 cents in I will toss mine into the ring. First I don't think that your Arduino could ever handle 8 UARTs full speed. I don't think that USB will work (again speed issues),

    first, remember that a URART is an 8-bit device with two registers, and the IO side of the gear you will need TTL to RS232 chip like a MAX back to the computer side of the world. all of the data lines are run in parallel between the USARTs and your CPU now. then you take the 8 interrupt lines and put them through an 8 to BCD encoder. As well as OR tieing them together to your interrupt pin.  the software looks at the interrupt pin, when it comes in it reads the URART address and gate the data on to the data bus and then read it. Here is a neet TI dual UART TL16C2752. Its package is a RHB 32 or QVFN 5mm x 5mm.

    Good Luck