Arduinoのブートローダ書き込み

AVRライタがある場合はそれを使えば良いが、Arduinoから入門した人はあまり持っていないことが多いだろう。 FT232RLのBitBangモードによって書き込めるツールが開発されている(FT245R/FT232R で avrdude (2)/ avrdue-GUI)ので、それを使うのが比較的お手頃だろう。ボードだと、Uncompatinoであれば、2X4ピンつなげばこのモードで書き込める。

MISO-CTS MOSI-DCD SCK-DSR RESET-RIをそれぞれ接続した状態でFT232RL対応版avrdueを使用する。avrdue-GUIでavrdue.exeの場所を指定し、DeviceはATmega328Pに、 uncompatinoのタイプの接続の場合、ProgrammerはFT232R diecimilaを指定。

バージン(買ってきてすぐ)のICは、内蔵RC発振モードになっているので、高速書き込みモードは使用出来ない。ビットを書き換えてリセットした場合、水晶発振モードになっていると、水晶が接続されていないと動作しなくなるので注意する。Arduino互換ボードであれば、水晶は基本接続されているので、あまり心配はいらないと思われる。

1) Portは空欄で良い、コマンドラインオプションで-P ft0 -B 76800を追加して低速モードでFuseを読み込み・書き込みできる。ファームウエアは容量が大きいととても遅いので、水晶発振モードにしてからリセットして高速モードで書き込む方が良い。hFuse=D9 lFuse=62 eFuse=07が初期値。これをhFuse=DE lFuse=FF eFuse=05にして書き込み、いったん電源を落とすかリセット。

2) コマンドラインオプションを-P ft0 -B 115200に変更し高速モードにする。Flashにoptibootのhexファイルを指定し、Erase-Write-Verifyで書き込む。

If you go to see Silicon Valley, what you'll see are buildings. But it's the
people that make it Silicon Valley, not the buildings. I read occasionally
about attempts to set up "technology parks" in other places, as if the active
ingredient of Silicon Valley were the office space. An article about Sophia
Antipolis bragged that companies there included Cisco, Compaq, IBM, NCR, and
Nortel. Don't the French realize these aren't startups?

Building office buildings for technology companies won't get you a silicon
valley, because the key stage in the life of a startup happens before they
want that kind of space. The key stage is when they're three guys operating
out of an apartment. Wherever the startup is when it gets funded, it will
stay. The defining quality of Silicon Valley is not that Intel or Apple or
Google have offices there, but that they were started there.

So if you want to reproduce Silicon Valley, what you need to reproduce is
those two or three founders sitting around a kitchen table deciding to start a
company. And to reproduce that you need those people.

    -- Paul Graham
    -- How to Be Silicon Valley ( http://www.paulgraham.com/siliconvalley.html )

I sent them [= the Application Architecture group] a copy of my spec and went
to meet them, in case they had something interesting to say.

"Blah blah!" said one of them. "Blah blah blah, blah blah blah!" said another.
I don't think they quite had anything interesting to say. They were very
enamored of the idea of subclassing and sort of thought that people making
macros in Excel wanted to subclass a lot of things. In any case, one of the
fellows said, "Well, this is all very interesting. What's next? Who has to
approve your spec?"

I laughed. Even though I had only been at Microsoft for a few months, I knew
that there was no such thing as somebody approving my spec. Hell, nobody had
time to read my spec, let alone approve it. The programmers were bugging me
every day to get them more pages so that they could write more code. My boss
(and his boss) made it very clear to me that nobody else understood macros or
had time to work on macros, so whatever I did, it better be right. And here
this PhD working in a strange research group at Microsoft assumed that things
were a bit more formal than that.

    -- Joel Spolsky
    -- "Two Stories" ( http://www.joelonsoftware.com/articles/TwoStories.html )

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