Little Wire - "Minimal AVR programmer and more"

[erdabyz]

A picture of the assembled littlewires:


Fboot works in 7 32 bit. I just programmed the bootloader to the tiny85 using an arduino as AVRISP and then I uploaded firmware 1.1 to both of them using the bootloader in a computer with windows 7 32 bit (my netbook).

Still haven't tested any function but I'm planning to program a few ATMEGA328's with the arduino bootloader using these littlewires, as they are far more convenient than using an arduino as AVRISP like I was doing. Maybe they'll also be used as serial to USB dongles. Maybe if i'm fresh tomorrow I could also test some of the other features.

[kehribar]

Hi,

It looks way much cooler! Thanks for sharing. :)

I would love to hear from your experiences/trials soon.

Best,
ihsan.

[Squonk]

Hi Ihsan,

As I was not one of the lucky persons to win a LittleWire, and that I had all the components available, I decided to build my own version... on perf board!

LittleWire on PerfBoard (top)

Doesn't look too bad from above, but...

... below it is a little but messier: as it is not strip board, you have to "bridge" all the pads with solder to create traces:

LittleWire on PerfBoard (bottom)

I was able to avoid wires, except for 4 of them (2 are a consequence of the funny ISP connector pinout).

I separated the 2 capacitors to have one close to the USB connector, the other one close to the ATtiny85.

I decided to put the jumper on the same R/A header, here is why:

LittleWire on PerfBoard (open)

I found this RX2KL05/S-5 Camden/Boss enclosure to be almost the perfect size for this baby:

LittleWire on PerfBoard (closed)

The enclosure is available at RadioSpares (unfortunately no longer at Farnell).
With a little cutter knife carving, it is a nice protection for this LittleWire derivative!

Needless to say, it is fully functional and once the ATtiny85 flashed with my BusPirate, it is working as expected!

Maybe this case could be used for the original LittleWire too?

[kehribar]

You sir, did a great job there! Well done, i'm simply amazed :D

Which features have you tested so far? I won't be tired of saying that, but i'll be glad if you can test the especially pic24f programming capabilites as well as i2c,spi and 1-wire. I really need user feedbacks :)

Best,
ihsan

[Squonk]

Thank you!

Sorry, I can't help you with he pic24f, I don't use them.

So far, I tested my perf-board LittleWire for AVR programming, I2C DS1307 and USB-CDC.

BTW, do you know Bitlash? It is an open source interpreted language for the Arduino, but it can also be compiled (with restricted features) for the ATtiny85. Maybe it is something to explore for the LittleWire?

[kehribar]

Hi,

You tested the DS1307 with the V1.1 firmware i guess? Thanks for letting me know.

I haven't heard about it since now. It says that "The Bitlash embedded interpreter that runs in about 14k of memory on an Atmel AVR processor" but you also stated the "(with restricted features)". I don't know maybe i'll look more detail in future ...

What is on my mind is actually writing an interactive console application at the PC side to ease up the protocol analysis and pin manipulation.

ihsan.

[Squonk]

Ok, I will let you know, I just did some simple tests up to now.

Regarding Bitlash, it may be a little too big to fit in the LittleWire (considering the USB stack), but if you look at the code, there are some #defines for the ATTINY85.

Maybe the idea of an embedded interpreter is not applicable to it, but the language syntax is nice and easy. It could be ported onto the host side, the ATtiny only executing pre-parsed intermediate bytecodes...

[Squonk]

Hi Ihsan,

You should have started a Kickstarter with the LittleWire:
http://www.kickstarter.com/projects/dig ... -dev-board

Just put the magic woed "Arduino"!!!

[kehribar]

Hi Ihsan,

You should have started a Kickstarter with the LittleWire:
http://www.kickstarter.com/projects/dig ... -dev-board

Just put the magic woed "Arduino"!!!

Hi,

I saw that project today on Kickstarter and feel weird as well. : )

I mean, apple and oranges OK; but one feel a little sad. Even though this project and mine is conceptually different, this one offers an "Arduino compatible dev board with supplementary code" on the other hand the Little Wire offers a complete hardware / software solution by giving emphasis on computer interface by making the hardware as a transparent bridge, one can thought that "Do i waste my time with contract manufacturing and making my project complicated and hard to explain? "

I mean, as an example, Hackaday posted my "Printf style debugging over AVR-ISP pins!" post but they couldn't get the essence of this project and couldn't explain properly on their post. I'm developing some neat, application specific and somewhat novel usage cases / projects, but is there really a point to develop such projects if i can't deliver what they actually do? I hope someday one will benefit from those projects :)

Also the blink(1) project collected 130k for an Attiny85 + RGB led :) It is cool and somewhat sad as well. Yes i'm overly simplifying his project by saying that but one should get the idea :) By the way i expect Digispark to reach 100k at the end of the month if he goes with this speed.

For the compatibility part, as far as i tell it isn't %100 pin compatible with the Little Wire but he might try to port it.

I saw the discussion on the Hackaday but i haven't enough energy to write a comprehensive comparison post there. Also i don't know if it is necessary or not.

On the other hand, as we talked about here, edge connector thing is not robust enough to put in a commercial product unless you take some strong precautions. Also V-USB based serial interface will consume much of the CPU time and the code space and also it has to be polled with strict timing requirements. He might implement timer based solution for this but i don't know ... There is too much pain to create something "just works out of the box" for his case.

I wish him the best luck :)

ihsan.

[hahihula]

Hi,
I just have finished my one. ;-) Maybe later I can post pictures of it. But I must say it was a pain to get it working. First what I have to mention is that for me it was not working under 64bit linux system (tried opensuse, debian and ubuntu ) I compiled the examples run them as root but even then i get "Little Wire could not be found!" message.
After that I tried 32bit Linux and Windows under Oracle VirtualBox enviroment. Also getting only "Little Wire could not be found!" (but i've seen it with lsusb ). This is strange because I normally use my usbtinny programmer under virtualbox without any problem (and without need for root privileges).
Finally I boot from ubuntu live-cd 32bit and get it working. Examples working as expected (I just tested GPIO and ADC, but I will test the rest).

I am running the 1.0 version, and was trying only the C examples. Is it better in v1.1 ? Or will it be better? Or I am just doing it wrong?

[Adam]

Hi Ihsan and others,

I've just finished porting the littleWire library to Python - I was surprised that no-one had already done it... (maybe they have and I just didn't find it?)

I haven't tested it 100% yet, but I thought it would be nice to get it out there into the wild as early as possible. I'd like to contribute it back to the main project so please feel free to take it and package it with the project. Also, please email any bug reports to apjohnson@gmail.com and I'll do my best to fix them ASAP

https://sites.google.com/site/something ... on-library

Regards
AJ

[Squonk]

Thank you Adam!

It is a very good thing indeed!

[kehribar]

@Adam

Thanks for the library!

I suggest you to open up a GitHub repo and continue your work from there. It will be much easier to work collaboratively and track issues.

On the other hand, it seems that you are using V1.0 C library but this version ,especially the firmware itself, has lots of bugs. You may want to take the V1.1 library as a base when creating your library. https://github.com/littlewire/Little-Wi ... nterface/C

You can look at this newly released Ruby library for the littlewire: https://github.com/littlewire/littlewire.rb Here my blog post about using this library on Windows: http://blog.kehribar.me/?p=226

@hahihula

V1.1 is defiantly better than previous version. Especially the SPI and I2C interfaces were a bit buggy. Also very nice features have come with the new release. You can find the changelog here: http://blog.kehribar.me/?p=139

ihsan.

[Adam]

Hi Ihsan,

As requested, I have hosted this at github. You are right, it probably is the easiest way.
http://github.com/adajoh99/VeryLittleWire

I have made it more clear that the library is based on the v1.0 code. I will have a look into the v1.1 code as well when time permits. At the moment I am trying to get a prototype up and running to log some data from an I2C sensor to support the mechanical boys at work. This seemed like the ideal way to do it.

Thank you for sharing this project with us, it has certainly proven to be a useful tool already!

AJ

[kehribar]

Hi,

Thanks for the kind approach! :) I'm going to fork this repo to the main organization account soon.

And by the way, you can move the Wiki page to the main Readme.md. Github Wikis are generally not very useful and very hidden under the menus. Using the Readme.md at the main directory is the best way to write a introductory message.

Also,

If you aim to use I2C, i suggest you to use V1.1 , you might have hard time to implement a robust system if you use V1.0 firmware.

Best,
ihsan.