I have an industrial breathalysers that outputs its status via a USB 2.0 OTG port. What might be a suitable combination of processor and perhaps Ethernet chipset. I have not played with the modern PICs and ARMs only the old old Z80s, 8051, 6800 and a few special custom chips.

Or is there a website "symptom checker" where one can specify ones needs and it will suggest a chip. I believe that most modern chips (including FPGAs, not that I intend to use one of these) have devices as added blocks so that the modern designer can keep his or her chip count down.

As the breathalyser is 12 volt I will provide 12 volt to this board with a suitable regulator. I am not sure if Ethernet has any funny voltage or current requirements. It would be better if whatever chip is suggested has a loadable library of an Ethernet stack (DHCP) and USB driver as no one will pay me to write these. Don't have the time or knowledge yet anyway.

I know that the "Internet of things" is becoming a thing! So there may be new chips or even SOC that I don't yet know about that is suitable.

I will need a programmable chip as some filtering of the status stream will be required before broadcasting the results to servers etc.

The breathalyser transmits its status as a continues stream of cr lf terminated strings. As I don't know different future requirements on filtering, the worst case scenario is a 4800 baud stream of characters that has to be sent to a server. Latency is not a issue. It is to record the value of the alcohol test with a date and time.

  • \$\begingroup\$ I have found the PIC Microcontroller selector page at microchip.com/maps/microcontroller.aspx \$\endgroup\$ – kingchris Apr 17 '15 at 10:50
  • \$\begingroup\$ How is it using usb otg, as a host or slave? Does it need drivers to work? \$\endgroup\$ – Passerby Apr 17 '15 at 20:49
  • \$\begingroup\$ There is no simple and general answer to such a question. There are several ways to go, and each has its drawbacks. To be able to give sensible help, you should first tell us a little bit more about the expected communication over the Ethernet network. Amount of traffic, latency requirements, kinds of protocols to be supported. \$\endgroup\$ – Laszlo Valko Apr 17 '15 at 23:12
  • \$\begingroup\$ Added a small paragraph @LaszloValko \$\endgroup\$ – kingchris Apr 18 '15 at 5:38
  • \$\begingroup\$ @passerby It should not need drivers but I may have to learn OTG to see how to decide who is master or slave. Learning curve always present. \$\endgroup\$ – kingchris Apr 18 '15 at 5:41

Try one of the TI tiva series devices. They have USB OTG and an on-chip Ethernet PHY. The SDK has example code for Ethernet with DHCP as well as USB. I think they have example code for both USB as a host and USB as a device.

  • \$\begingroup\$ @alexforencich which chip are you thinking off. I don't see one that has ethernet with it. Unless I am looking at a narrow range of these chips. \$\endgroup\$ – kingchris Apr 20 '15 at 15:24
  • \$\begingroup\$ TM4C1294 should have it. That one comes on a decently priced dev board. Not sure which other ones in the line would also work. \$\endgroup\$ – alex.forencich Apr 20 '15 at 17:24

If you can coax your device into talking to Arduino over USB OTG, this pre-made solution will work: Arduino + Ethernet shield

  • \$\begingroup\$ Lol ""pre made"" \$\endgroup\$ – Passerby Apr 17 '15 at 20:47

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