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[Reply #15 on:]

@Coding Badly: What are the actual speeds you get? (roughly)

Arduino 1.0.1-rc2
avrdude 5.11

Times are reported by avrdude.  Rate is bytes per second for a write then verify.

Breadboard Uno running 250K baud Optiboot 4.4 with the Pololu programmer as the USB-to-serial converter: 5313.9

Pololu to an ATmega328P running at 16MHz (2M SPI): 4573.5

Teensy 1 running TinyISP to an ATtiny85: 1628.6

Uno running TinyISP to an ATtiny85: 1481.4

Uno running the stock ArduinoISP to an ATtiny85: 352.4

I'm working on a project where I have to upload via ISP (not bootloader) and I am uploading a sketch of 9308 bytes (program memory) or 26208 bytes (hex file size) in 11 seconds, using the Arduino via SD card system I devised.

846.2 bytes per second. 

http://www.gammon.com.au/forum/?id=11638

pollUntilReady ... that and fixing heartbeat makes the biggest difference to ArduinoISP.

I don't feel particularly annoyed at waiting that long. That time includes reading the file from SD and checking its integrity, uploading and then verifying the upload. There is an additional overhead of a few seconds to move the SD card from the Mac to the card reader.

Dude.  You need a programmer.   

[Reply #16 on:]

Dude.  You need a programmer.   

OK, well I plugged in my USBtinyISP into the board under test. It has an Atmega32U4 on it, although it isn't a Leonardo. Since that is the same chip as the Leonardo I selected Leonardo in the Boards menu. (It's actually uploading using ICSP not the bootloader / USB interface).

My time to upload and verify was 45 seconds, compared to 11 seconds using my programmer. Maybe the configuration (in boards.txt) can be improved, but so far that is a lot slower. Using USBtinyISP that was only 215 bytes per second uploaded, whereas with my Uno as a programmer it was 879 bytes per second.

pollUntilReady ... that and fixing heartbeat makes the biggest difference to ArduinoISP.

Are you suggesting a fixed delay?

[Reply #17 on:]

pollUntilReady ... that and fixing heartbeat makes the biggest difference to ArduinoISP.

Are you suggesting a fixed delay?

No no.  The fixed delay is horrible.  The Atmel specification calls for a very conservative (read that as "way too long") delay.  Polling (when the target supports it) is most definitely the way to go.

ArduinoISP uses a fixed delay which is one of the reasons it's so slow.

[Reply #18 on:]

Dude.  You need a programmer.  

My time to upload and verify was 45 seconds... Using USBtinyISP that was only 215 bytes per second uploaded...

Ouch!  Dude.  You need a better programmer.  

[Reply #19 on:]

You don't need to remove the bootloader in order to upload Arduino-less code.

Wait what?

The bootloader is just a piece of software that is loaded in the AVR that allows
a tool (avrdude in this case) to upload code to the AVR. The bootloader itself
is totally independent of anything Arduino.

As shipped the AVR fuses are set to create two sections in the FLASH. Bootloader and application.
The "Arduino" bootloader is small piece of code in the AVR that uses the serial port to update the flash
with the user application (code/program/sketch).
The bootloader runs at reset/powerup if there is no attempt to upload anything, the bootloader
will start the application code.
The application code can be written using any toolset you prefer. The Arduino tools are just one option.

avrdude is a tool that is used upload code into the flash.
avrdude can be used with an ISP programmer to upload code to the flash
avrdude can also use other mechanisms like a serial port that talks to a serial based programmer or to a bootloader.
The Arduino IDE uses avrdude to talk over a serial port to a pre-installed bootloader in the AVR chip.
The newer IDE can also use an ISP progammer to upload code. When an ISP programmer is used,
a bootloader is not used so the flash space used by the bootloader code frees up and can be used
by the application code.

If you don't want to use a bootloader, you will need some sort of ISP programmer.
Like Pico, I recommend getting a USBasp programmer off ebay.
I like the USBasp kk multicopter programmers (about $5-$10 USD) because they come with a 6 pin ISP
cable instead of 10 pin so no adapter is needed.

--- bill

This cleared up a lot of things, thank you Bill.

[Reply #20 on:]

$10 for the pololu programmer is a bargain.

Got that right!

Coding..., out of curiosity why would you resort to using an Uno when you have a pololu programmer?
Teensy I understand as it should be faster because of the native USB support, but why use Uno?

Upload performance from fastest to slowest...

• Uno with a 250K baud bootloader

• Pololu (very close to the same speed as above)

• Teensy running TinyISP

• Uno running TinyISP

• Teensy running ArduinoISP

• Uno running ArduinoISP (very slow)


The first two are very close to the programming time listed in the Atmel datasheet and are essentially the fastest possible method using SPI.  (Again, I highly recommend the Pololu AVR Programmer.  It was worth the $20 I paid for it (now just $10).)

TinyISP on either hardware is not as fast by a noticeable amount but is still fast enough to fall within the "two second" rule¹.

ArduinoISP is just abysmal.


I use the Uno or Teensy because of the amenities that I've added to the Arduino ISP sketch (TinyISP is available here).  It makes a "good enough" programmer with some very basic debugging tools.

I like the Teensy because, inserted in a breadboard, it makes a very nice "project board".  Breadboard + programmer + basic debugging for ~$30.  What's not to like?

I like the Uno because it's easier to move from one project to another.  Getting the Teensy out of a breadboard is a little annoying.


¹ Humans perceive a computer response within two seconds to be reasonable.  At five seconds, humans tend to get impatient and annoyed.  At ten seconds, they tend to get angry.  Past that, the monitor gets a fist, a boot, or a bullet.

What bootloader is that exactly, that allows the fast baud rate when using the UNO as ISP?

[Reply #21 on:]

What bootloader is that exactly, that allows the fast baud rate when using the UNO as ISP?

The context of your question is difficult to divine from the way you quote.  I assume you are referring to this...

• Uno running TinyISP

If that is the subject matter then the bootloader is irrelevant.

[Reply #22 on:]

What bootloader is that exactly, that allows the fast baud rate when using the UNO as ISP?

The context of your question is difficult to divine from the way you quote.  I assume you are referring to this...

• Uno running TinyISP

If that is the subject matter then the bootloader is irrelevant.

I suspect sTrider_7 is actually referring to this

• Uno with a 250K baud bootloader

which, given the topic context, he think is using the Uno as an ISP and programming w/o a bootloader (rather than comparing the performance of a fast bootloader on the Uno with various ISP programmers.)

[Reply #23 on:]

 

• Uno with a 250K baud bootloader

 Is this a optiboot that is not currently supplied with the Arduino IDE? Is there a link the code for this?


 By the way Coded Badly, thanks for the break down of programmer speeds!

[Reply #24 on:]

im also fascinated by relative speed of various programming methods. of the half dozen ive tried bootloader beats others hands down. lpt 4 wire slowest (probably due to 1us pc in/out penalty. however unlike coding i notice no difference between 115k and 230k. it would be interesting to see how those baud rates fit in with maximum theoretical atmel burn time. ie is there really any room for improvement over 115kb download of a hex file. btw i never verify because imo theres no point.

[Reply #25 on:]

• Uno with a 250K baud bootloader

Is this a optiboot that is not currently supplied with the Arduino IDE?

Yes.  It is not supplied with the Arduino IDE.  The one that comes with the IDE is configured for 115200 baud.

Is there a link the code for this?

Unfortunately, no.  I don't think I even kept a copy of it.  I built it solely to answer two questions, "Does baud rate make a significant difference?" and "Is 250000 baud reliable?"


The answer to the second question is "yes", 250K baud is reliable.  I suspect 500K is also reliable but I have not performed any testing.


The answer to the first question...

Arduino 1.0.1-rc2, Avrdude 5.11

#1: Uno, Optiboot 3.3, 115200 baud: 2821.8

#2: m328p on a breadboard w/ Pololu as converter, Optiboot 4.4, 115200 baud: 3403.1

#3: m328p on a breadboard w/ Pololu as converter, Optiboot 4.4, 250000 baud: 5313.9


The serial converter makes a difference (#1 versus #2).  The Pololu appears to be a more efficient converter.

The baud rate makes a big difference (especially on the verify pass) (#2 versus #3).

By the way Coded Badly, thanks for the break down of programmer speeds!

You are welcome.  If I ever have time, I'll write-up the details (and try to remember to post a link here).

[Reply #26 on:]

Thanks for the info Coding Badly

[Reply #27 on:]

More details and Optiboot compiled for higher baud rates...
http://zygomorphic.com/arduino-tiny/?page_id=249

[Reply #28 on:]

More details and Optiboot compiled for higher baud rates...
http://zygomorphic.com/arduino-tiny/?page_id=249

 Thanks for the link! It is a good read but, it seems that the link for the bootloader files is no longer active. It leads to a page related to signing up to Rowdy Dog Software for information???

[Reply #29 on:]

Ouch.  Sorry about that.  I'll get it fixed in a minute...

Fixed.