next topic »

[on:]

Hi all,

I'm a relative newcomer to the Arduino, but have been tinkering with it for a while now. I bought an official Arduino UNO, plus ethernet shield and they work great.

However, for a new project I'm looking at building a single board that is essentially Arduino+ethernet+microSD. There are various affordable ethernet boards out there, but most don't include SD and require programming directly through serial, as opposed to the convenient USB connection offered on official Arduinos.

Basically, my question is whether or not I can easily add a 3rd-party USB-to-serial chip to allow programming on a custom 'Duino via USB. I was looking at this chip: http://uk.rs-online.com/web/p/universal-asynchronous-receivers-transmitters/0406580/

and thought it would perhaps be suitable. Would anyone be able to confirm/deny this? If I'm completely wrong here, would you be able to suggest an alternative that would work?

I know the Arduinos (of late) use another Atmel chip programmed as a serial converter, though these chips are (to the best of my knowledge) only available in tiny packages, hence pretty impossible for me to solder.

As a side question, regarding the popular ENC28J60 ethernet IC (which I would be using), I understand that the chip has no hardware TCP/IP stack, so it has to be implemented via software. Is this fairly reliable or does it carry issues with it? I was wondering if the code would greatly reduce the size of applications you can write.

I'd be very grateful for any help you can offer.

[Reply #1 on:]

That FTDI chip is what was built into the Diecimila and Duemilanove models of Arduino.  If you are used to surface-mount soldering techniques then it's a good solution.

Many Arduino clones don't include the USB-to-Serial part.  They just provide a 6-pin header for an FTDI Cable which you can buy various places for about $20.  This saves space and money if USB communication is not needed in normal use, just for programming and debugging.

[Reply #2 on:]

You could also probably try using your UNO to program it...I use my UNO all the time to upload sketches to my multiple  home built/standalone arduinos... You'll need the AVRISP sketch on your UNO and then connect the ICSP pins of your standalone chip to the UNOs pins (10,11,12,13) and upload by pressing "upload using programmer" (assuming you've already selected your ATMega version from the boards menu, selected the right serial port, ad have a machine running Arduino 1.01). It'll take a little bit longer to upload the sketch, but it works perfectly for me... Let me know if you need info/help

Cheers!
Mr_E

[Reply #3 on:]

Many thanks to both of you.

To be honest I'd completely forgotten that you could program it using another device! As this board is going to be a prototype and will likely be programmed several times, I might opt for the hardware option, though it's great to know I don't actually need it (or the pricey FTDI cable).

Thanks again

[Reply #4 on:]

Could also add an inexpensive CP2102 module, like $3 on e-bay. Find one with holes along side; cut the RST trace, wire the header pin to the DTR hole. Good to go for USB/Serial comm's.

[Reply #5 on:]

Good Luck on it! Let me know if you have any problems/troubles...

Cheers!
Mr_E