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31  Using Arduino / General Electronics / Re: how to do 6 to 9volts to 360 to 400v step up Dc? on: January 04, 2012, 11:16:54 am
You might want to look at some proven circuits. Geiger counter HV circuits are all over now.
Sparkfun has a simple one with a transformer (see schematic) . . .

But one I really like that uses a 555 and a small inductor is here.
It provides an adjustable and regulated 200-500V.

32  Using Arduino / Project Guidance / Re: 9v to HV supply for Geiger counter on: December 11, 2011, 02:52:04 pm
You might check this circuit out. (credit to Tom Napier for the original)

It supplies a regulated 200-610V without using a transformer and only draws a few mA.
BTW, I wouldn't suggest the SI-3BG tube. It is one of the least sensitive.
I have a comparison and sources of GM tubes here.
33  Using Arduino / Programming Questions / Re: Switch to Optiboot Causes Sketch to No Longer Compile on: October 07, 2011, 12:25:00 pm
Just to say thanks for your work and clarification, and also to point out what lead to my confusion, in case it helps.

The search took me to the bootloader with the core, along with your beta testing thread. "Naturally" I picked the bootloader with core. ;-).

This gave me "[optiboot] xxx" lines in the boards menu. So I assumed you needed a different boards setting to load a sketch to a chip with optiboot. (Even though this didn't make sense considering that optiboot is now being sold with pre-loaded ATmega328s.)

However, it did make some sense, because it wasn't obvious from what I read that you just use the Uno as the target. (I have an old Diecimila). So I thought I did need a boards entry to get the higher baud for uploads. It wasn't until CodingBadly mentioned the Uno that the light went on, and it's all good.

So that's my tale of woe (whoa!). Not complaining, but if I had read something like a "How To use Optiboot" it would have saved a lot of, well, woe. (It does fit in with my tag line, however.)

34  Using Arduino / Programming Questions / Re: Switch to Optiboot Causes Sketch to No Longer Compile on: October 03, 2011, 01:36:48 pm
Yea, or moths in the tubes!
Great news, thanks!
35  Using Arduino / Programming Questions / Re: Switch to Optiboot Causes Sketch to No Longer Compile on: October 03, 2011, 01:11:35 pm
I'm under the impression that once I have an ATmega loaded with optiboot, I still need a boards.txt for optiboot in order to download a sketch to the chip.

If I have the wrong impression, and you can just use the stock IDE that would be great!
(The gremlin on my basement machine may have been hiding this fact.)

I've tried the OptiLoader program and it's lightning fast, just couldn't load a sketch with my funky machine.
36  Using Arduino / Programming Questions / Re: Switch to Optiboot Causes Sketch to No Longer Compile on: October 03, 2011, 10:16:35 am
I didn't realize there were two versions of this, and that one was so old.
I downloaded westfw's branch, but I'm not clear on what I must do to integrate it into the IDE. I take it that it must be compiled?

I have another issue as well. It seems my "basement machine" won't load the sketch at that speed. (My other PC's do.) Not sure where the problem is - USB? Serial? I installed the latest FTDI drivers with no joy. It's the same issue I posted where 1 out of 10 new ATmega328's wouldn't take a sketch on that machine. (You posted a nice picture of a gremlin regarding that problem.) I'm not asking for a solution to this unless someone has an idea.

Regarding a switch to optiboot, if I understand correctly, the two current options are; use one that's easy to install but is based on Rel 0018, or learn how to install westfw's beta. However with as many vendors selling chips pre-loaded with optiboot, it seems I must be missing something. If not, I think I'll have to wait until it's ready for prime time, as I have users that would have to deal with adding it.
37  Using Arduino / Programming Questions / Re: Switch to Optiboot Causes Sketch to No Longer Compile on: October 01, 2011, 11:11:33 am
Same issue as the OP with SPI.cpp. Got v3 optiboot from as I assume the OP did.

Here is another example:
SD lib - ReadWrite example - ReadWrite:47: error: 'class File' has no member named 'println'

Wasn't sure if it was something about my configuration, or if it's an an issue with the optiboot package.

Replacing . . . hardware\optiboot\cores\arduino with  hardware\cores\arduino from Arduino-0022 allows the sketches to compile.
(Stream.h, WCharacter.h, WString.h, WString.cpp are not included in the optiboot cores)

(Reading the response to the OPs bug report, it sounds like String won't be supported, but I wasn't clear on what the rest of the response meant.)
38  Using Arduino / Displays / Re: Is there a HD44780 compatible 16 x2 OLED out there? on: September 17, 2011, 03:39:28 pm
Same situation with the "confused line numbers" and other annoyances with that display. I first described them here.

Some observations that may help:
- For me, the problem 'almost only' happens on reset. If the display is powered down, it's almost always OK.
- lcd.clear() often doesn't reset the cursor to 0,0. (Made a clear function that adds that.)
- FWIW, the LiquidCrystal_I2C lib runs that display without the mods needed for 4 bit in the LiquidCrystal lib.

Too bad! Other than that it's a great display - bright and sharp. It's the only character based OLED I know of. The graphic OLED displays I've seen require a software character set, which is fine if you have the memory and a decent sized set.

39  Using Arduino / Networking, Protocols, and Devices / Re: Blocking Blues: TWI, Serial and SPI together on: August 10, 2011, 12:52:50 pm
What I'm thinking is that every second a GPS sends a torrent of data.

If that's part of your problem, shut off the constant data from the GPS and only request the sentence when you need a fix (so to speak). i.e.
// send the GPS these strings on init . . .
#define GGA_OFF  "$PSRF103,00,00,00,01*24\r\n"
#define GLL_OFF  "$PSRF103,01,00,00,01*27\r\n"
#define GSA_OFF  "$PSRF103,02,00,00,01*26\r\n"
#define GSV_OFF  "$PSRF103,03,00,00,01*27\r\n"
#define RMC_OFF  "$PSRF103,04,00,00,01*20\r\n"

// send this just before you check for a read . . .
#define RMC_READ  "$PSRF103,04,01,00,01*21\r\n" //  used to REQUEST a RMC sentance

40  Community / Exhibition / Gallery / Arduino B/W TV (w/ accelerometer & compass) on: July 17, 2011, 09:36:08 pm
I only get VHF channels 2-13 so far - working on UHF.

Sorry, couldn't resist.
It does have a compass and accelerometer in it.
The idea was a gizmo for the car.
The case is made from copper clad PCB board.
Details on my blog.
41  Community / Gigs and Collaborations / Re: Company Looking to Hire Arduino Uno Software Developer on: July 11, 2011, 03:33:16 pm
Really? And this would be PCI compliant?
I'm sure your company has thought this through, but to some people it might sound like you want to build an RF skimmer.
42  Using Arduino / Sensors / Re: Geiger counter datalogger w/RTC for Chernobyl on: July 07, 2011, 03:14:41 pm
I have Geiger logging sketch for the Adafruit data logging shield, that you might find useful . . .

It's not "Chernobyl certified", so take appropriate cautions with anything you will bring there.

43  Topics / Home Automation and Networked Objects / Re: Noob question about X10 on: July 06, 2011, 03:44:27 pm

Why not?
- 1) The dependability varies with the environment. If something noisy is plugged in near a module it may not work.
- 2) It has limitations that some might not like - delay, no confirmation the command was received.
- 3) The sense I get from other peoples complaints.
If you're asking technically why not, I don't have the time nor the details to go into that.

I don't get what does "1/2 house" means for you. Can you describe that problem?
It's not an issue for you. It has to do with how US houses are wired with 2 phases of 115VAC.

What can you advice me for 220V countries?
Personally, I have no good advice for you. I'm sure other will.
44  Topics / Home Automation and Networked Objects / Re: Noob question about X10 on: July 06, 2011, 03:19:32 pm
I control my whole house through X10 with Arduino and it works fine - for me. I would never consider it "rock solid" however, but I don't need it to be.

The "1/2 house" problem was solved for me with a $14 repeater/phase coupler. As for dimmable CFLs I've yet to find a decent CFL that works with any standard dimmer.

Having said this, I never recommend X10 to 220V countries. The modules are 4X more expensive, so the "not rock solid but cheep" rule doesn't apply.
45  Using Arduino / Displays / Re: OLED 16x2 character display on: June 26, 2011, 05:00:33 pm
"Plugh" worked pretty well, although I'm still in a maze of twisty little passages.

You can make the following mod to the "begin" function in LiquidCrystal.cpp (libraries folder) . . .
void LiquidCrystal::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
  if (lines > 1) {
    _displayfunction |= LCD_2LINE;
  _numlines = lines;
  _currline = 0;

  // for some 1 line displays you can select a 10 pixel high font
  if ((dotsize != 0) && (lines == 1)) {
    _displayfunction |= LCD_5x10DOTS;

  // according to datasheet, we need at least 40ms after power rises above 2.7V
  // before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
  // Now we pull both RS and R/W low to begin commands
  digitalWrite(_rs_pin, LOW);
  digitalWrite(_enable_pin, LOW);
  if (_rw_pin != 255) {
    digitalWrite(_rw_pin, LOW);
  //put the LCD into 4 bit or 8 bit mode
  if (! (_displayfunction & LCD_8BITMODE)) {
    // this is according to the hitachi HD44780 datasheet
    // figure 24, pg 46

// FOR OLED INIT - Runs before regular init - does not affect non-OLED
    delayMicroseconds(4500); // wait min 4.1ms
    delayMicroseconds(4500); // wait min 4.1ms
    delayMicroseconds(4500); // wait min 4.1ms
    delayMicroseconds(4500); // wait min 4.1ms
    delayMicroseconds(4500); // wait min 4.1ms

// FOR OLED INIT - must comment out the 3 0x03 commands . . .
    // we start in 8bit mode, try to set 4 bit mode
    //delayMicroseconds(4500); // wait min 4.1ms

    // second try
    //delayMicroseconds(4500); // wait min 4.1ms
    // third go!

    // finally, set to 4-bit interface
  } else {
    // this is according to the hitachi HD44780 datasheet
    // page 45 figure 23

    // Send function set command sequence
    command(LCD_FUNCTIONSET | _displayfunction);
    delayMicroseconds(4500);  // wait more than 4.1ms

    // second try
    command(LCD_FUNCTIONSET | _displayfunction);

    // third go
    command(LCD_FUNCTIONSET | _displayfunction);

  // finally, set # lines, font size, etc.
  command(LCD_FUNCTIONSET | _displayfunction);  

  // turn the display on with no cursor or blinking default

  // clear it off

  // Initialize to default text direction (for romance languages)
  // set the entry mode
  command(LCD_ENTRYMODESET | _displaymode);


Basically you send 5 (0x00) commands before the standard init and comment out the 3 (0x03) commands.

It needs work however. I see the following issues . . .
  • reset doesn't always work correctly
  • sometimes the line numbers get mixed up
  • the "createChar" function is not working and stops the display from working
I got the above info from NKC, and also a data sheet (attached). The data sheet also has a description of 4 bit init, but I've had no luck with it.

It's a gorgeous display. Highly visable, no contrast or backlight needed, low power.
I hope someone can get the kinks out.
(I was hoping to make an alternate init for this in the sketch and keep the LiquidCrystal lib in tact, but I had no luck with that approach.)

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