2

An old software question of mine looks like it would benefit from some hardware.

Basically, I have a web page and want it to communicate via HTTP to a small controller, which will read a string from the serial port and return it to the browser.

Don’t worry about the software, I can handle that. I am wondering which hardware to use, and would like to keep the price down.

The requirements are simple enough. The device needs to be able to read from serial port, and it needs to be able to receive HTTP requests - I don’t care how. I don’t really need an operating system, certainly not a full blown one, but I do need to be able to run a web server, to handle the HTTP request.

I was thinking Raspberry PI, but am one to other solutions if they are cheaper and if they are as simple to code. I can buy in quantities of a dozen up to maybe 100, if it offers a decent discount.

[Update] I also need a dozen or two GPIO pins

Possibilities:

  • Raspberry Pi 3, plus RS232 hat
  • Raspberry Pi Zer0, plus RS232 hat and Wifi or Ethernet (will also need a USB hub)
  • Netduino, plus RS232 shield

Long term availability of the device might play a role. E.g maybe not use Pi2, in case it gets phased out. Widely available support , via forums, would be good, although the project is so simple that I don’t envisage needing any help.

Which of these., or an alternative, can do what I want, with an emphasis on cost, but also balancing other terms? Hmmm, I probably want to put it into a case, preferably IP 67 compliant.

[Update] I am also considering:

Although I am not sure how compatible they might be with Raspberry Pi peripherals

Community
  • 1
Mawg says reinstate Monica
  • 1,125
  • 6
  • 18

1 Answers1

2

Check this board "atmega328" with serial port around $2 / without serial port $1.5 on aliexpress enter image description here

A wireless shield will cost you around 1.5$ also on aliexpress Or this little guy ESP8266 the newer one for $1.70

Here is a project about ESP8266

enter image description here RFID reader around $1.70, 6 DATA PINS and 2 for VCC, GND from here

Narzan Q.
  • 234
  • 1
  • 6
  • There are quite a few atmega328XX - which are you recommending? A full product name for both would eb nice, or, even better, a link. Btw, I have added an update to say that I also need a dozen or two GPIO pins - would this board still be acandicate? – Mawg says reinstate Monica Feb 24 '17 at 07:47
  • 1
    What about telling me for what exactly you want it for! so I can give you better answer! There is other things you should consider like the chip memory and the serial port speed, and what language you will use! "I can buy in quantities of a dozen up to maybe 100" I can design custom one if you want. – Narzan Q. Feb 24 '17 at 12:24
  • There's not really much to say. The web page prompts the user to scan an RFID tag, which currently requires an OCX control in the browser. I would like to make it more cross browser, by dropping the OCX control. I thought that I could do it by having the web page make an HTTP request to a controller which would read the RFID tag using an existing serial port connected reader. ---------------------- I now realize that an alternative solution would be a cheap processor with WiFi & RFID reader, no need for serial port. – Mawg says reinstate Monica Feb 24 '17 at 15:26
  • 1
    Okay with serial port you don't need WIFI shield! easy setup, but with WIFI shield you need a PC or Clint! you can't make a webpage connect to your board without a static IP address and you should open port inside your router to communicate with your boards, if you want to mange all these devices on your LAN network you can use other ways to a accomplish that. anyway I will edit my answer and I will add some links and info. – Narzan Q. Feb 24 '17 at 18:53
  • You have already answered the question - very well, so I will award it, BUT, you have got me thinking that Wifi + RFID reader is a good alternative, with no serial port, so I have asked a new question http://hardwarerecs.stackexchange.com/questions/6922/small-cheap-processor-with-rfid-reader-and-internet-access if you have any ideas – Mawg says reinstate Monica Feb 24 '17 at 19:38
  • 1
    I don't know how you will manage to make your web-page to communicate with your device, anyway you can find a lot of RFID reader on aliexpress around $2 depends on the pins, the cheap one will use 8 PINS while the expensive one 4PINS only. and about your other question, I don't think there is RFID with WIFI and and a controller on the same board and cheap in the market. I added RFID to my answer – Narzan Q. Feb 24 '17 at 20:14
  • 1
    I think that the device must have a static 192.178.xxx.xxx or 10.xxx.xxx.xxx address. Even then, I need to think about it. Should probably work if I insist that the PC also have a fixed address in the same subnet (in addition to any others, e.g. dynamic from ISP). Thanks for the update on your answer. You have been extremely helpful – Mawg says reinstate Monica Feb 24 '17 at 21:39
  • I want to send an HTTP request to it, from JavaScript, whcih will tell it read an RFID tag's serial number from a reader connectioned over UART and return it in the HTTP response. A really dumb thing, and 9600, 8, N, 1 is enough, with not much code – Mawg says reinstate Monica Feb 27 '17 at 16:16