what is the recommended isp for general use? (328 and 2560)

What do most people use for isp? I know there's a couple, so what's the easiest to use with the ide and works with most devices?


AVRISPmkII. It's the standard. It is reliable. And it can vary its clock speed as well as measure the target voltage.

Where is a good online store to buy it from? I usually get my stuff from ebay, but the usbasp I got I used on a bricked mega2560 and at first it said error cannot set sck period then I turned on verbose upload so I could figure out what command to put in avrdude to do it myself on watever speed works and suddenly it said it was working, weird part is I think the 8u2 on the board is also burnt as it says it doesn't respond, and when I burn the bootloader in the mega I get pin 13 blinking erratically but in a pattern, and when I upload a sketch to blink 13 nothing happens so idk if I trust it with a good board, id rather buy something legit I know will work also do you know any good gui's to use the programmer to set the fuses? I know it can be done with avrdude but I really am clueless on how to use that

AVRISPmkII needs board/chip to be powered externally.
AVR Studio 5.1 is good for setting fuses wth MKii as well.

Mouser.com has them for $33 if I recall.

I've heard, however, that AVRISPmkII needs different firmware depending on whether you're using Atmel tools or OSSW tools (Avrdude.) USBTiny doesn't do 2560 :-(

The ISP programmer confusion is one of the reasons that Arduino uses a bootloader...

I have always used my Arduino as ISP.. and now recently with recommendation from Crossroads and a few others.. I use Arduino with Optiloader on it..

Note that ArduinoISP also does not program 2560s...

[quote author=Udo Klein link=topic=98862.msg741207#msg741207 date=1332971264] AVRISPmkII. It's the standard. [...] [/quote]

Got any numbers for write/read speed in kb/s ?

Why can't arduino isp work with the 2560?

Why can't arduino isp work with the 2560?

The STK500v1 protocol used by ArduinoISP does not support uploads of more than 128kbytes. (now, it DOES support "random SPI command", so in theory, the right host-side software could program the second 128k bytes VERY SLOWLY (~6 bytes serial traffic per byte programmed, vs ~1 byte)

Even if its a small sketch it wouldn’t work? Where does the 128kbs size apply to?

Small sketches should work. But you can't, for example, use ArduinoISP to program the MEGA bootloader, because that is loaded at the end up memory.

The actual limit is on the address of the "page" of flash memory to be loaded. Addresses are defined to be in instruction words, and a page is typically 32 or 64 bytes, so you can easily load 128k bytes (64k words.)

Interesting. Is there a project in the works to update the Arduino sketch to STK v2 (assuming that fixes the address limit)?

Is there a project in the works to update the Arduino sketch to STK v2 (assuming that fixes the address limit)?

Yes, stk500v2 fixes the addressing limit, and yes, I have been "experimenting" with porting stk500v2 (the implementation from the 2560 bootloader, actually) to an ArduinoISP-like application. It seems to be going OK, but it is probably premature to say that there is an update "in the works." (at best, I'd expect ArduinoSTKv2 to get added, rather than replacing the existing ArduinoISP.)

Testing is a bear. Mostly because I like tiny programs, and have trouble even imagining working on a sketch/program longer than 128k. (so for example, I don't have a MEGA2560, and only have a MEGA1280 because I was kindly given one (and I haven't figured out what to do with it.))

Maybe I should leverage that Cryptography class I'm trying to take, and my networking background, and work on a fully secure SSH/SSL networking example. That should fill up memory pretty dang fast.

Well since the bootloader is last shouldn't that alone prove to be a test as over the 128kb limit?

As I posted in another thread, I got one of those recently and simply can’t get the Mac to recognize it. So it may well be fine for Windows. I got no response either to a query about what to do about that. And the Atmel website is strangely silent about Mac support.

Personally I find, for the occasions when I need to program via SPI, the USBtinyISP works pretty well. Sometimes I have to unplug and replug it to be recognized, but apart from that.