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1  Topics / E-Textiles and Craft / Re: Flexible displays? on: October 15, 2014, 12:44:09 am
Its been a while.

LG Flex is out there, but ... the display is fused to the plastic, which is not all that flexible.

I tried removing it and failed.

Has anyone else had more luck? Anyone stumbled across any new modules? I found this here:

considering testing it, but actually interested in something bigger.

2  Using Arduino / Microcontrollers / Re: Uploading code to multiple microcontrollers simultaniously on: September 07, 2014, 06:20:02 pm
haha ... NOW we're talking :-)
3  Using Arduino / Microcontrollers / Re: Uploading code to multiple microcontrollers simultaniously on: September 07, 2014, 03:58:45 pm
Ha. Thanks for the Transputer link. I did not know about it. Reading up on xCore and XMOS now.
4  Using Arduino / Microcontrollers / Re: Uploading code to multiple micro-controllers simultaniously on: September 06, 2014, 05:54:05 pm
Thanks Rob

I'll take some time to look into your suggestion in more detail.
5  Using Arduino / Microcontrollers / Re: Uploading code to multiple micro-controllers simultaniously on: September 06, 2014, 05:42:52 pm
@ Paul__B
Your post confuses me - you say that I "still did not address a question" which never was asked and you are telling me things I *must* do. ... to clarify. I am simply brainstorming here. I am just curious to hear some of the thought from people in this forum.


- I understand that the Atmega328p is quite average in regards to its functions.  I am wondering if there might be other devices designed specifically for this type of scenario. I am not expecting the perfect microcontroller, I realize that most of the heavy lifting will have to happen on the software side, I am just curious if someone might know of a microcontroller which is better suited for this type of task.

- What makes you think I misunderstood Graynomads question? I am aware of the limitations of i2c, but thanks for pointing it out.

- To answer your question explicitly:
 The topology of the nodes is arbitrary, which is the entire point of the exercise in the first place.

EDIT: However because the topology is arbitrary they could be reconfigured for programming, though I would prefer to avoid that. Also, even though the physical topology is arbitrary, I could still have them electrically be connected in parallel.
6  Using Arduino / Microcontrollers / Re: Uploading code to multiple micro-controllers simultaniously on: September 06, 2014, 04:09:18 pm
@everyone - thanks for your input. as often is the case, I probably should have provided a bit more context to start out with:

I would like to design a series of 'processor nodes' which can execute parallel algorithms. The reason to have physical elements is in order to have a fast and intuitive way of exploring interactions between the algorithm chosen and the topology of the nodes.

e.g. "it works when arranged in a square, what happens if I arrange them in a triangle shape?" imagine being able to prune a neural network by physically removing nodes and seeing the effect of the pruning in real time...

The goal is to create a tool which helps visualize and better understand parallel algorithms.

In the end, I do not need to actually 'reprogram' the individual nodes. Each node will be continuously executing a function - in order to do the type of rapid iterations I have in mind, I need students to be able to tinker with that function. Changing details of the code has to be effortless enough for this to retain some element of fun and exploration.


you are taking me a bit too literal. I do not necessarily mean 'program them all at once'. I mean 'program them all in a single step':
I want to be able to edit my code and then click 'upload' without having to repeat the process for each and every node.
having said that, simply by connecting the signal lines, there is no reason not to talk to multiple nodes simultaneously (I have done this both intentionally and by accident in the past by writing super sloppy i2c code using the wiring library)

the nodes would be 'all in the same box'.

you are suggesting that I use a separate eeprom chip for storing code? would that not simply defer my problem? i.e. instead of talking with an arbitrary number of controllers I now communicate with an arbitrary numer of eeprom chips? Would you mind elaborating on your suggestion? I am not sure I fully understand it.

Thanks PeterN for digging up those threads and Crossroads for the suggestion. I had seen those earlyer, but they feel a bit too much like a 'hack' to me. I am hoping to hand over this plattform to software guys and I am hoping for the platform to be stable enough, so whoever is using this to experiment can focus on the algorithms. I will try doing it this way, but somehow that feels like a solution prone to cause problems somewhere further down the line.


Right now I am tending towards the idea of not actually reprogramming them, but rather changing parameters via i2c. But I am curious in other solutions - maybe there are other microcontrollers which would be better at this thing, or maybe I am not thinking about this in the right way. I don't have any formal training in any of this, so sometimes I miss the obvious.

Thanks & Regards

7  Using Arduino / Microcontrollers / Uploading code to multiple microcontrollers simultaniously on: September 04, 2014, 02:41:27 pm
Hi everyone

I am looking into a project which will require a way of uploading code to an arbitrary number of microcontrollers.

Ideally I would want to upload the code simultaneously.

EDIT: This is not a 'one shot' reprogramming. I need to be able to reprogram them frequently, so pre-ordering them programmed is not an option. Also the number of micro-controllers is (as stated) arbitrary (between 6 and ~144) so multiplexing them is not practical (though possible).


At this point there are basically no constraints yet - nothing has been decided upon yet, so I could be using any type of controller; I could potentially even write my own bootloader. Having said that, ideally I would want to work with the atmega328p and the Arduino bootloader.

I have read that simply wiring them in parallel is prone to errors if they do not synchronize properly. Has anyone actually *tried* this?

How would you go about doing that? I'm open for any suggestions (mechanical/electrical/software solutions etc.).


8  Using Arduino / Project Guidance / Re: eye blink sensor on: September 02, 2014, 11:11:30 pm
EDIT: just realized this is an old thread which sort of got derailed :-/ gonna pm the OP, but leave this here for posterity

I only skimmed the thread, so apologies if it was already mentioned.

IMO this project is *exactly* what you need:
Its an eye-tracking system designed to help an artist with ALS be able to draw again

Here is a tutorial on how to build it:

Assuming you have some basic tools you can build the eye-writer for under ~75$

9  International / Deutsch / Re: Arduino Stromversorgung on: August 24, 2014, 01:11:28 pm

Also, vom Datenblatt:

– ATmega164P/324P/644PV: 0 - 4 MHz @ 1.8V - 5.5V, 0 - 10 MHz @ 2.7V - 5.5V
– ATmega164P/324P/644P: 0 - 10 MHz @ 2.7V - 5.5V, 0 - 20 MHz @ 4.5V - 5.5V

Du siehst, theoretisch kannst du den controller mit 1.8V bis 5.5V versorgen, je nach der geschwindigkeit von dem resonator/crystal.

Ich benutze oft eine LiPo-Batterie direkt mit dem Atmega Chip (also 3.6 bis 4.2v) allerdings laeuft der mit 8Mhz (nicht die 16, wie die meisten Arduinos)

Wenn du dir unsicher bist was die toleranzen von deinem system sind und wenn du die option hast einen voltage regulator (also den Vin pin) zu benutzen, wuerd ichs tun. Aber wie gesagt, es ist nicht notwendig.

(ahhh. das war schmerzhaft. ich hab noch nie auf Deutsch ueber elektronik gesprochen. Es ist gar nicht so einfach - mir fehlt das komplette vokabular dafuer.)
10  Community / Products and Services / Re: IO Visualizer for Arduino on: August 24, 2014, 12:32:11 pm
I like this, but I probably would not buy i

- I can't justify the price (it takes me about 5 minutes to write the code)
- I am not sure how it will interact with other serial I/O which might be going on and
- As I don't have the source code, I can't fix in any potential issues myself. Also, I don't trust a company I don't know to provide continued support on software like this :-/

Anyway, I do really like this, if it were a simple library i'd be using it a lot I think.
11  Community / Bar Sport / Re: How many times is someone not replying after asking question ? on: August 23, 2014, 04:36:58 pm
the 'my latest post' and 'unread replies' buttons are quite useful ... maybe they should be pointed out a bit more explicitly. They could be pointed out on Nick Gammon's 'how to use this forum' thread... though I doubt the people who *should* read that thread actually read it...
12  Community / Bar Sport / Re: connectors on SMD modules [follow up: do elecrow, itead or seed do half vias?] on: August 23, 2014, 04:29:41 pm
@Rob - Ah. Makes sense now. Probably won't be able to try this though ... I guess 4 layers is the new 2 layers. But at the same time the price of 2 layers has dropped so far that it would be unreasonable to use 4 layers unless its absolutely necessary.


I got my order from itead back within 10 days. They also through in an additional circuit-board (I payed for 10, they delivered 11). Overall very uncomplicated and positive experience.


I need to play around with the pads a bit and there are a bunch of details I got wrong, but, in general I am very happy with how it turned out. I am attaching images of the pcbs and a screenshot of my eagle file.

The PCBs are basically Arduini pro mini clones. The main purpose of this board was just to test my design, see how castellations work and check if the pin sizes really are what I want.

The larger castellations are 2mm pitch, the smaller one 0.05". I'll probably stick with the 0.05" cause they seem easy enough to soldier.
13  Using Arduino / Interfacing w/ Software on the Computer / Re: Easy to get started with freeware programing language for windows on: August 17, 2014, 11:23:58 pm

I use
14  Using Arduino / Sensors / Re: need sensor which can detect human presence on: August 17, 2014, 11:22:05 pm
You need to tell us a bit more about your project.

I'd probably try webcam, capacitive sensing or pressure sensors (under the floor), depending on what the application is.

15  Community / Bar Sport / Re: connectors on SMD modules [follow up: do elecrow, itead or seed do half vias?] on: August 16, 2014, 10:32:37 pm
@ SirNickity - Please share some pictures if you do :-)

@Rob - I don't understand what you mean by this
One thing you should do is connect them to internal layers with pads, this helps save them from being ripped off by the router.

Would you mind elaborating?
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