Freitag, 23. November 2012

Programming an ATtiny85


I recently decided that I wanted to use an ATtiny85 for a small project I have in mind. So I ordered a couple from DigiKey. Once I got them I realized that I only had a very vague Idea on how to go about programming them. 
I ended up following instruction from the brilliant people of the High-Low Tech group at MIT: http://hlt.media.mit.edu/?p=1695 

Some things I noticed:
- Their instructions do *not* work with Arduino 1.0.2.
- Dont forget to select the correct board *and* the correct programmer (selecting a programmer was new to me, its in the "tools" menu)
- Yes, the Capacitor is essential. I didn't have 10uF capacitor around the first time I tried it. I tried various wrok-arounds (multiple capacitors in paralel, larger values, smaller values) and nothing worked. (In retrospect, at one point I did get it to work without the suggested capacitor, however there was a different problem, but I was unable to fix it, as I assumed it was the cap. So my recommendation: Just get the capacitor and it'll save you trouble.

Also, use the suggested debugging LEDs. It makes it a lot easyer to understand what is happening.

Here is my setup:


Green LED tells me the ATmega is talking to the ATtiny:


Once I finally got it running I basically fell in love. This thing is sooo simple. It works like magic. No external oscillator, no nothing. It just works. I think in many situations, once you have the initial setup its easier to use than the Arduino. I realized I will want to program ATtinies more often, so I decided to make myself an ATtiny programming shield:


I used a protoshield which I piked up from the METALAB at some point and had lying around. I connected everything like so: 



In addition I added a yellow LED + Resistor on pin 9 (Heartbeat - tells me the programmer is working OK). I also added a red LED on pin 8 (Error) and a green one on pin 7 (communication). The small green LED you see next to the ATtiny is for double-checking if everythng works. Its connected to pin 0 of the ATtiny and is executing the 'blink' sketch which I just uploaded to the ATtiny.


Sorry about the shoddy fotography. If I find a decent camera I might upload some nicer images.

This was a fun project and well worth the time :-)


Donnerstag, 1. November 2012

Kickstarter - A recap of my campaign


I recently successfully funded a project of mine via Kickstarter (link: http://www.kickstarter.com/projects/808216251/mediated-touch-a-telepresence-study). People have been curios about how the process went, so I decided to quickly recapitulate my experience. 

First of all, there is lots of stuff on how to run a Kickstarter campagin and stats about Kickstarter out there. I personally found this website the most helpfull while running the campaign: http://www.kicktraq.com/


So lets take a look at my project:

How did it go?




I marked some interesting points on this graph. 
(1) Begin. This was awesome. I basically clicked submit on the Kickstarter page - just because I was curious *if* it would work. And it did. Then I thought "I should send out an e-mail to people, telling them about this". By the time I had finished that thought, I already had my first backer, a former lab-mate. I ended up opting for not spamming my entire e-mail contacts, but selected a few ~ 20 people who I sent a message to, asking them to forward it to people who might be interested. 

Within the first day, I was backed with over 400$, of which 65$ where from people I knew - the rest where strangers to me. This was quite a thrilling experience. I could not really understand it - it was only later that I realized Kickstarter had selected my project as a staff pick:

During the next couple of days, my project was plastered all over (my corner of) Facebook by me, friends, people I study with and, to my surprise, the odd person who was a stranger to me. Also, people continued backing, and very soon, I hit my goal of 950$

After that things started stagnating a bit. Then something even worse happened. I lost money. I was not even aware this could happen. What I learned is, you must not only convince people to back you, you must continously keep them convinced. Loosing backing was quite a blow to my moral. However, I guess its just one of those things which happen and should not be taken too seriously. I never found out why the two people who 'backed out' backed out.

Things changed half way (2). This was a strange day. I don't know if this is random, or if this is significant. It might also explain day one. What happened is this: My Grandmother, Mother and Aunt decided to back my project with 300$. (It was done from one account, so they do not appear as individual backers). Then all of a sudden, 3 more people backed it, with substantial amounts of money. Quite a day, I was really hyper.

However, as with day one, one of the backers rescinded their backing.

I really did not do much in form of marketing. Towards the end of my project (4) I sent a fb message to a couple of friends who I knew would most likely be happy to back my project, asking them to do so, and telling them not to worry about adding a large sum, I really am just interested to see if I can get more backers. Most of them backed it. On the last day (and some even within the last hour) a bunch of friends ended up making the effort to back my project (5). I would guess that I know around 30 of the 100+ people who backed my project in person. About half of those backed it in the last two days.

And then, of course as soon as the backing period was over (6), I got a bunch of messages by people apologizing for missing the time-window. I assume, if I had written to these people in person, they probably would have backed the project as well.


 Here some more statistics from Kicktraq

After a big backer backs out, things look sad:



It can be corrected though:



 Entire course of project, including trend at each day:



What did I learn


This is what I did right
- My project is very unique. I think this contributed to it being featured on Kickstarter. Without being featured, things would have been very different.
- My project was appropriate in scale to my network. Luckely things went well and I did not have to take any extreme measured, however, before starting I sort of considered which networks I have (family, university, former work, friends in Canada, friends in Austria, friends in the Netherlands) and estimated how much backing I could potentially get if I reached all of them. The project I intended to do, and the reach I thought I had aligned nicely, so I figured I might be able to do this.
- The presentation. I think people liked my video and the way I had things set up. I think it was professional enough for people to believe that I can pull off my project, while being honest and personal enough that people felt comfortable giving me money even tough my rewards where not the most tangible ones. (a lot more people than I would have anticipated opted for the "no reward" option.

This is what I did poorly
- My funding goal. After I had almost reached my goal of 950$, I realized that I had actually anticipated to overshoot that goal by ~ 600$. However all of a sudden I found it difficult to explain to people why I needed their backing, even though I already had 100%. The backing also stagnated once I had reached 100%. This was a huge mistake. I did this, as I was planning on doing my project anyway, and even the 950$ would have been valuable, however I learned this: Be bold. Ask for as much money as you need. If you don't ask for the right amount in the first place, it is hard to justify this later on
- The rewards. This was probably the weakest point of my project. I did not know how to do them, as, unlike most Kickstarter projects, I am not designing a product and I am *not* interested in distributing and selling things. Because of that I thought that I need not put so much focus on this. Well, I think now that I was wrong. For example, I ended up receiving additional backing from one person after some exchange, in which I asked him what type of reward he actually would like to see. After I introduced that reward, he almost doubled his pledge. I did this on the last day. For me it all worked out - I got what I needed and am happy with my project. Next project, first thing I will work on will be the rewards.


A word of warning:

Kickstarter does not initially mention, that you will pay additional fees on top of the 5% which Kickstarter keeps. When it does it says Amazon keeps between 3% and 5%. 

What it does not mention however is that Amazon does not apply this percentage equally to all transactions. For the 1$ pledges I ended up paying 11 cent to amazon. So from every 1% pledge I get to keep 0.84$. This is quite hefty in my opinion. From 5$ pledges Amazon keeps between 0.30$ and 0.35$. Thats 6% to 7%.

All in all, I ended up receiving 89% of the total amount pledged. That is, in my opinion, a lot of fees. I am happy paying Kickstarter these fees, as I feel like it was extremely beneficial that I could use their platform  however, I am not sure how I feel about the Amazon fees.


Some links:


I found following blogpost to be extremely interesting  especially interesting:  http://boardgamegeek.com/article/8849498#8849498

More interesting discussion can be found here: