Remote pump control ideas.

[Dannyx]

Re: Remote pump control ideas.

I just thought of something I thought would be trivial but could end up being tougher than I thought: connecting multiple clients to a single server....not too sure yet what hardware I'll be using and how this affects the difficulty of this task.

For the pump project, this is easy: one client - one server, but here's there's several "ears" which have to report to the server which has to differentiate between them (separate warning light for each of them) and I don't think they can all hog the same port (23 in the case of the pump project)...I think I have to create multiple server objects on the server board and have each client connect to its own server. I think we're talking about multi-threading capabilities here which requires more advanced hardware...

[Dannyx]

Re: Remote pump control ideas.

That's a good point....guess they can spare an Ethernet jack in each room then Now to settle on an appropriate board. The STM one is.....kinda oversized for this application I think Still, Ethernet-capable boards tend to be overspec'd like this. Cost is another aspect, since I imagine there's like 5-10 rooms and I can't blow my budget on a single room...

[stj]

Re: Remote pump control ideas.

i personally wouldnt use any type of radio for safety critical alarms/monitors.
the liability if they get jammed at the wrong moment is huge.

[Dannyx]

Re: Remote pump control ideas.

I/O count is not a problem, since for this next project I was talking about, the end goal is to essentially create some "ears" which light up the corresponding room number on a panel located in the night watch office to alert the staff if any of the newborns start crying - yes, that's right: I'm talking about a newborn ward at a private clinic here They also want this to double as a listener for any alarms given off by the incubators or whatever monitoring devices they have in these newborn wards........which I right away suggested is a VERY poor way of implementing this sort of monitoring when dealing with something this important. I insisted that we instead have a look at said devices to see if they don't already feature some sort of communication interface and use THAT instead (seems logical), but the management or whoever's in charge said I just go ahead and go down this other route, so I jut took off my hat and delivered (pun intended )...sort-of. I'm just messing with some mic modules I picked up off Ali for cents....not the most high-tech solution when considering we ARE talking about newborns and what could be time-sensitive situations Not sure how I feel about this...

[stj]

Re: Remote pump control ideas.

if you mess with ESP chips then make sure you know what your buying, some have an antenna socket, some dont - and the ones that do, you often have to enable it by moving an inductor or cap on the board.

problem with ESP's is a lack of i/o pins.
great for serial protocols to wifi or bluetooth(ESP32) but crap for loads of switches/transistors!

[Dannyx]

Re: Remote pump control ideas.

go look at https://os.mbed.com/

Looks interesting. If I understand correctly, it's an IDE for ARM-based boards, which supports multiple platforms, doing away with compatibility issues that arise when limited to Arduino's own IDE. Seems a bit excessive for very simple projects like this one, but I guess it's a good idea to look beyond Arduino for becoming a "big boy"

There's also RaspberryPi which I've been wanting to get into...in fact, there's so many solutions it makes your head spin I imagine the proper approach for choosing one is based on the project: you don't send an Arduino up in space, nor do you use a supercomputer to turn on some lights, so I think knowing a bit of everything is good. They all seem to share the same language, so moving between them should be feasible enough, even for yours truly who is clearly NOT the sharpest pencil in the box

if your employer is playing the stupid "preferred supplier" game that i'v seen too often then they obviously arent too serious about doing things properly for clients.

To a degree, they DO have preferred suppliers, but if the job calls for it and there's no other option, alternatives are accepted, within reason, provided shipping is not a killer. For this project, I have a full list of parts and materials which I tried sourcing from TME, so we only have to pay the single shipping fee. Trouble is the Nucleo's not on there...

I have another project underway which could benefit from some small Wi-Fi-capable MCUs. ESP8266 might be a candidate. The idea is similar to the pump-tank one (client reports stuff to server which does stuff), except here there's multiple clients - one in each room - which should hook up via Wi-fi and sit in a corner somewhere to avoid wires and junk as much as possible....what "rooms" we're talking about and what the system is supposed to do is beyond the scope of this discussion and should be its own thread

[stj]

Re: Remote pump control ideas.

go look at https://os.mbed.com/

about boards,
you choose the best, not the one in stock.
if your employer is playing the stupid "prefered supplier" game that i'v seen too often then they obviously arent too serious about doing things properly for clients.

[Dannyx]

Re: Remote pump control ideas.

but if the configuration is different then it may not work with your arduino ide

I had this worry even WITH the Nucleo, though I did find a library for the Arduino IDE which put my mind at ease a bit...I wonder if the code can be easily adapted for boards other than Arduino, so instead of trying to use the IDE, I use whatever the particular board works with natively...

[stj]

Re: Remote pump control ideas.

but if the configuration is different then it may not work with your arduino ide
just use a different supplier.

[Dannyx]

Re: Remote pump control ideas.

My project hit a snag right off the bat: the F767 board I initially chose for the build is not in stock, so I'm trying to find a replacement

I found this Olimex thing which is more expensive, but looking past that, seem to be roughly the same thing - still STM32...

[Dannyx]

Re: Remote pump control ideas.

True - I found it: page 74. The regulator is U5, which is THIS, so it takes a max of 15v on the input.

[stj]

Re: Remote pump control ideas.

the schematics are in the pdf's,
you can see the regulator and caps used and work out the max input from that

[Dannyx]

Re: Remote pump control ideas.

I know that, but the absolute maximum rating is nowhere to be found. The datasheet simply says it can accept up to 12v on its 12v input (which is naturally then stepped-down by that regulator tot 3.3v), but there's no mention of how hard you can overvolt that 12v input before something pops (the regulator probably)....wonder if it can take up to like 35v like most regulators can, at the expense of maximum current you can then draw from it. I imagine it's pretty resilient...

[stj]

Re: Remote pump control ideas.

the nucleo is actually 3.3v - it has an onboard regulator.

[Dannyx]

Re: Remote pump control ideas.

Another thing came to my mind about the hardware: would it be wise to drop some sort of zener protection on the input of the MCU ? The Meanwell PSU I proposed outputs 12v AND 5v, so I have the option of powering the Nucleo with either....not sure which would be better. Regardless, would a resistor+ a 13v zener be a waste of time or mandatory ?

The "sump" end is powered only by 12v for now, since it's solar powered and I'm not sure how much that controller overshoots, so it's the same thing there: I should probably design some sort of basic protection...maybe even better: with a PTC fuse so it resets by itself after a spike.....didn't think it through yet. The datasheet doesn't quite make it clear how much these nucleos consume - I think it's 300mA....either that, or I'm plain stupid and don't see it, which is the more plausible explanation, as always

[Curious.George]

Re: Remote pump control ideas.

This is the issue I was facing, as described.

I don't know squat about advanced programming stuff (like threads), hence why I'm using layman terms most of the time. The Arduino IDE uses C++ and from what I understand it's fairly potent, by my standards at least, if you know how to do it. I did it by ear, so stuff is not up to snuff...

"Language support" is like advertising you have shiny hubcaps on your old klunker. The most powerful/effective programming tool is the environment supported by the "OS" (or, "RTOS" -- to use a often abused misnomer).

Here's a "program" (thread/task) to control an LED. It allows "something" to indicate whether the LED should be OFF, ON or BLINKING (at some predetermined rate).

extern state;

Drive_LED() {
  state = OFF;
  while (FOREVER) {
    switch (state) {
      case OFF:
        LED = OFF; break;
      case ON:
        LED = ON; break;
      case BLINK:
        LED = ON;
        sleep(1000);   // ON time, in milliseconds
        LED = OFF;
        sleep(500);    // OFF time, in miliseconds
        break;
      default:
        break;
    }
  }
}

Note that there's no mention of ANYTHING else in your "device" ("system") other than the issues that are of interest to driving the LED. Even someone completely ignorant of the language chosen and the actual details of what the statements actually DO (or how they do it) can suss-out what is happening. (in order to make code "accurate", you really want to make it easy to understand)

You can embellish this to handle any number of LEDs and ensure that they blink in "unison" (instead of each coming on "whenever" and winking off some time after that).

The above code snippet can be bound to C, C++, ASM and be equally obvious. I.e., the language doesn't buy you squat!

OTOH, try doing this in a single-threaded environment regardless of language AND making sure those times (1000, 500) are guaranteed.

[stj]

Re: Remote pump control ideas.

if you do that, you need to zip them to get round the attachement filter.
then people have to download them to view!

copy/paste is better

[Dannyx]

Re: Remote pump control ideas.

^^Well if you do please use CODE tags in your post, so the formatting is not lost.
I added them to your post #48, looks much prettier at least

True, but I was planning on uploading the INO files anyway, not the code as text....not sure if that's the way to go around here.

[Per Hansson]

Re: Remote pump control ideas.

^^Well if you do please use CODE tags in your post, so the formatting is not lost.
I added them to your post #48, looks much prettier at least

[Dannyx]

Re: Remote pump control ideas.

Not sure whether I should post my code here for others to see or not It's a mess and I'll probably get roasted good but it's the only way one learns and gets better at something I guess....