SBC in a BOX

[Doctorandus_P]

The picture below is what is usually regarded as a SBC with serial in a box. I don't understand why you're rambling on about an arduino, I hate those things.

Yes, I agree, you don't understand. 

How much are these boxes.  Anything under $500?

They start at around EUR300.

[robert.rozee]

The application is to accept data from one serial port, process that data in very, very simple ways, then output data on the other serial port.  The average data rate is much lower than the bit rate of the serial ports, so very little buffering is required.  A small program - maybe 100 to 200 lines (not counting serial port and start up code).

i'm guessing you want is to no longer do assembly in-house?

while you are unlikely to find anything pre-made that fits all your requirements, there are any number of small businesses (or individuals) out there who could throw together a design that fulfills your needs, and is a fraction of the cost (per unit) of the many hundreds of dollars for what others have been suggesting. they may also be able to complete assembly to the closed-box stage for you.

a few questions:

1. what is the box to be powered from? an existing 5v/9v/12v source? please specify lower and upper limits. are you happy for there to just be a barrel jack on the side for power in?

2. are you OK with 2x DB9 plugs or sockets for the serial ports?

3. do you prefer the box contains an arduino NANO, or a raspberry pi PICO? in some regards the PICO is a little easier to work with, but on the other hand you may wish to retain your existing code and so go for a NANO. PICOs have one big advantage today in that they are readily obtainable.

4. the box would additionally have a hole in the side for uploading firmware, as well as possibly a push button for selecting upgrade mode.


whoever designs this for you will lay out a PCB that is shaped to fit an existing enclosure with removable ends. such as this one for example:
https://nz.element14.com/hammond/1593lalgy/enclosure-instrument-abs-grey/dp/3276681
there will be two DB9 at one end, and power in and USB cutout at the other. the NANO or PICO will plug into the PCB. it is highly likely that the PCB manufacturer will be able to also load components. see, for example:
https://jlcpcb.com/smt-assembly
i believe JLCPCB can also patch-mount a PICO if you go down that path.


is this getting close to what you are after?


cheers,
rob   :-)

[gnuarm]

The application is to accept data from one serial port, process that data in very, very simple ways, then output data on the other serial port.  The average data rate is much lower than the bit rate of the serial ports, so very little buffering is required.  A small program - maybe 100 to 200 lines (not counting serial port and start up code).

i'm guessing you want is to no longer do assembly in-house?

while you are unlikely to find anything pre-made that fits all your requirements,

I don't get this.  The requirements are pretty minimal.  That's what has surprised me, that there are no box level products at the low end.  Literally TONS of board level products (well, if you don't include the RS-232 drivers).  It's like the market is all about playing with MCUs rather than using them in useful products.

there are any number of small businesses (or individuals) out there who could throw together a design that fulfills your needs, and is a fraction of the cost (per unit) of the many hundreds of dollars for what others have been suggesting. they may also be able to complete assembly to the closed-box stage for you.

a few questions:

1. what is the box to be powered from? an existing 5v/9v/12v source? please specify lower and upper limits. are you happy for there to just be a barrel jack on the side for power in?

120V as provided in the US.  This can be a wall wart.

2. are you OK with 2x DB9 plugs or sockets for the serial ports?

The serial ports should be DB-9 connectors. 

3. do you prefer the box contains an arduino NANO, or a raspberry pi PICO?

It doesn't need to be an Arduino, but any processor typically run without an OS.  I suppose an rPi could be used, but they typically are used with an OS and that's an unneeded encumbrance.

in some regards the PICO is a little easier to work with, but on the other hand you may wish to retain your existing code and so go for a NANO. PICOs have one big advantage today in that they are readily obtainable.

This is such a simple application that the OS provides virtually nothing to the task.  The only I/O is the RS-232 interface which only requires simple UART support.  Not really a justification to drag an OS into the game.

4. the box would additionally have a hole in the side for uploading firmware, as well as possibly a push button for selecting upgrade mode.

This is currently being done on the Arduino using the serial port (not ports).  The one port is split between input and output of the serial stream.

whoever designs this for you will lay out a PCB that is shaped to fit an existing enclosure with removable ends. such as this one for example:
https://nz.element14.com/hammond/1593lalgy/enclosure-instrument-abs-grey/dp/3276681
there will be two DB9 at one end, and power in and USB cutout at the other. the NANO or PICO will plug into the PCB. it is highly likely that the PCB manufacturer will be able to also load components. see, for example:
https://jlcpcb.com/smt-assembly
i believe JLCPCB can also patch-mount a PICO if you go down that path.


is this getting close to what you are after?


cheers,
rob   :-)

This thread is about finding a box level product, not designing and constructing boards. 

[tooki]

MCU boards are typically called “dev boards” (development boards) precisely because they’re used during development; the typical next step is to design your own board. Dev boards aren’t about “playing”, but development. What they aren’t intended for is use in a final product.

[gnuarm]

MCU boards are typically called “dev boards” (development boards) precisely because they’re used during development; the typical next step is to design your own board. Dev boards aren’t about “playing”, but development. What they aren’t intended for is use in a final product.

Thank you for your advice.

[westfw]

a few questions:

Good questions!
But let's cut to the chase:
How many are you going to buy, on what sort of schedule?

You might be able to negotiate with Brainbox to get programming info and wholesale prices for one of their boxes, which is pretty close to what need, apparently.  (aside from have a whole extra ethernet an enough guts to support it.)

I've done that - found a box whose guts would run "our" software, and had "my people" negotiate with the manufacturer to let us resell the box with our own software (re-branding the box, giving us enough data to program it, etc.)  It was a very expensive product, by today's standards...  (the cisco STS-10, if you're curious.  a 10port Ethernet to RS232 "terminal server." I saw the original CMC box at a trade show, asked whether they'd sell us the bare box, set the ball in motion, as it were.  It was an "OK" product, I guess.  Filled a niche that we weren't willing to spend our own HW design resources to build.)

[gnuarm]

a few questions:

Good questions!
But let's cut to the chase:
How many are you going to buy, on what sort of schedule?

You might be able to negotiate with Brainbox to get programming info and wholesale prices for one of their boxes, which is pretty close to what need, apparently.  (aside from have a whole extra ethernet an enough guts to support it.)

I've sent Brainbox a couple of emails.  We'll see if they respond.  So far, not even an acknowledgement I've reached a human.

[Jeroen3]

Are the protocols used somewhat standard? Maybe you can find an anybus converter...

Anyhow, what I know is available are embedded pc's with intel atom class pc's for less than a few hundred that have two real serial ports (eg: IBASE).
You can run a headless linux on those launching your python processing or whatever. Optional IO header for your button or status light. They are robust and last for years.

[gnuarm]

Are the protocols used somewhat standard? Maybe you can find an anybus converter...

Anyhow, what I know is available are embedded pc's with intel atom class pc's for less than a few hundred that have two real serial ports (eg: IBASE).
You can run a headless linux on those launching your python processing or whatever. Optional IO header for your button or status light. They are robust and last for years.

I didn't find anything useful searching under Anybus, assuming that was a product name.  They make much more complex systems than I  am looking for.  The only "converter" I was able to find is a module to allow the internal signals to be shifted to RS232 levels.

I did find these devices.

http://www.artila.com/en/p_matrix.html#Matrix-504

But they are not so cheap and still run Linux.   But it shows that looking for a self contained unit that is not a full PC is not unreasonable.

[gnuarm]

I've not been able to find a box with appropriate "guts" to do this job.  But I have found appropriate "guts" without the box.  I was getting ready to go with a low end PC in a box (~$300) and found a company that makes a dual RS-232 interface for the Arduino Mega.  It seems like a good fit. 

Now I still need a way to get an affordable box built.