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91  Using Arduino / General Electronics / Sourcing soft headphone cable on: July 16, 2013, 09:25:03 am
Does anyone knows where I can get same kind of cable that's used in headphones, i.e. very easy to bend?  With 2 or more stranded conductors inside, doesn't have to be shielded...  Appreciate any suggestions smiley
92  Using Arduino / Project Guidance / Re: Best 1+ Watt amp IC that can run from 9 Volt battery? on: July 14, 2013, 04:22:41 pm
Wow, that's awesome amp! Anything similar in DIP package? 5v is also ok...
93  Using Arduino / Project Guidance / Best 1+ Watt amp IC that can run from 9 Volt battery? on: July 14, 2013, 03:38:51 pm
LM386 can only do 1/2Watt. Is there another IC that will let me amplify mono signal to 1 or more Watt (on 8ohm Speaker) while being powered by 9 Volt battery?
94  Using Arduino / Microcontrollers / Re: How to enable BOD fuse? on: July 03, 2013, 08:28:05 pm
Sorry, it was not clear you were using the bootloader to upload the sketch, since you had to use an ISP programmer to change the fuse bits.

For clarification are you using a custom bootloader to upload at 19200 baud?
Sorry I'm fairly new to AVRs... Are you saying that baud rate depends on type of Bootloader?
I'm using standard Sanguino bootloader with ATMega644p chip. It's a custom board I made so it doesn't have USB onboard. There are basically two ways I upload sketches to it, either by connecting FTDI adapter or uploading sketch to the 644p chip directly with my "Rapid bootloader shield" which basically sits on top Uno R3 and uses it as ISP programmer.  I found 19200 baud option in one example posted on Sparkfun so I'm using it and it works great.
I just find it quicker to upload a chipInfo sketch using Arduino as ISP (right after I burn bootloader), however I want to preserv ability to later upload sketches via FTDI.
I've programmed about ten 644p chips using avrdude with "-e" switch and while all of them appeared to be working, week later I found out that I cannot upload anything via FTID, which almost caused me to loose my mind smiley Then I realized problem was in the method that I was using to upload "test" sketch, it was erasing Bootloader in the process. I experimented with different avrdude switches. Only when I added -D switch I was able to upload sketch via ArduinoISP and keep bootloader intact. It didn't make a lot of sense to me first (since it "disables Erasing before programing"), but after your post I now closer to understanding why it works.
Anyway I got pretty far from my original post about fuses, but I just wanted to give warning to other newcomers who might stumble on this thread in search for answers smiley
I didn't test if setting fuse works with "-D" command, only did hex program upload.
95  Using Arduino / Microcontrollers / Re: How to enable BOD fuse? on: July 03, 2013, 07:44:40 pm

No this will not work correctly from ISP programming.  You will see it will not work once you change your program.  Try adding a line to you code and then re-upload it with that command again.  It will probably not work anymore.

The flash memory cannot be programmed to back to a "1" once it is programmed to a "0" unless you erase it.  The -D option only works with a bootloader because it does a page erase at a time instead to reprogram.  If you reprogram via ISP then the only way is to erase all flash first.


That was my point, this is supposed to work with Bootloader.
96  Using Arduino / Microcontrollers / Re: How to enable BOD fuse? on: July 03, 2013, 02:44:02 pm
I just realized that I can just use Arduino as ISP to program Fuses smiley
Since I created Rapid BootLoader shield, it's pretty easy to do it with that...
In case someone finds this useful:
Code:
avrdude -C S:\programs\arduino\hardware\tools\avr\etc\avrdude.conf -P COM11 -b 19200 -c avrisp -p atmega644p -v -e -U efuse:w:0xfd:m
I verified it works great. Just replace path to avrdude.conf and COM number to your environment smiley
HUGE WARNING to anyone who uses above command to actually upload HEX sketch to the chip!!!!
As I just discovered it erases Bootloader!  Apparently because of the "-e" switch and lack of "-D" switch.
If you interested in uploading sketch without loosing Bootloader use this command:
Code:
avrdude -C c:\programs\arduino\hardware\tools\avr\etc\avrdude.conf -patmega644p -cavrisp -P\\.\COM5 -b 19200 -D -Uflash:w:yourhexfile.hex:i
97  Using Arduino / General Electronics / Re: micro SD Card capacity variance on: June 30, 2013, 08:14:43 am
Thank you all!
BTW these cards format as FAT (I guess it's = FAT16) with SDFormatter utility.

Also I found out how to open these cards, all you need is some nitric acid smiley This is how it's done:
http://www.bunniestudios.com/blog/?p=918
98  Using Arduino / General Electronics / Re: micro SD Card capacity variance on: June 28, 2013, 05:03:12 pm
Heh, how do you open micro SD?  It's as thin as paper :-)
99  Topics / E-Textiles and Craft / Which hot glue gun do you use/recommend? on: June 28, 2013, 02:28:24 pm
I'm using hot glue gun a lot lately, and it's a cheapo one. I'd like to upgrade to something better w/ features like on/off switch, very quick initial heating up and drip protection (if there's such thing). Any recommendations?
100  Using Arduino / General Electronics / micro SD Card capacity variance on: June 28, 2013, 12:43:53 pm
I'm very curious about something. I just bought 120 micro SD cards in size of 256Mb for my project. They are from various manufacturers. What is strange to me is that capacity varies from 240 to 243. How is this possible?  Some show up as 240, some 241, 242 or even 243 smiley
Dead cells?  Cards supposed to be new, and they look but I can't really tell for sure smiley
101  Using Arduino / Microcontrollers / Re: How to enable BOD fuse? on: June 22, 2013, 06:03:33 am
"efuse:w:0xff:m"

Only the lower 3 bits are programmable in the '328P extended fuse byte.
111 = no brownout detection (0xFF, or 0x07)
110 = 1.8V (0xFE or 0x06)
101 = 2.7V (0xFD or 0x05)
100 =  4.3V (0xFC of 0x04)
Oops it supposed to be "efuse:w:0xfd:m"
102  Using Arduino / Microcontrollers / Re: How to enable BOD fuse? on: June 21, 2013, 01:19:00 pm
I just realized that I can just use Arduino as ISP to program Fuses smiley
Since I created Rapid BootLoader shield, it's pretty easy to do it with that...
In case someone finds this useful:
Code:
avrdude -C S:\programs\arduino\hardware\tools\avr\etc\avrdude.conf -P COM11 -b 19200 -c avrisp -p atmega644p -v -e -U efuse:w:0xfd:m
I verified it works great. Just replace path to avrdude.conf and COM number to your environment smiley
103  Using Arduino / General Electronics / Re: Battery life with step-up converter on: June 21, 2013, 10:01:43 am
Speaking of art of electronics I have cheap Atomic clock with wireless external temperature sensor. That sensor sits outside my window and runs of 2 AA.  Besides transmitting temperature it has built in small LCD display and LED. It's there in freezing winter temperatures or hot summer days, yet it works on same set of batteries for 2-3 years.  I don't know how the heck they managed to achieve such crazy efficiency (magic?), but I'm really tempted to take it apart smiley
104  Using Arduino / Project Guidance / Re: Laser interrupt sensor on: June 20, 2013, 03:55:37 pm
Quote
what happens when the led/diode stops working.
The in-built self-test detects it?
Ah yes, excellent idea!
I've used more than 1,000 led's , and even though they have 100,000 Hours , some have only lasted for 2 days. Which one will last the 100K Hours probably 5% or 95% or none.

The best led's were the original Gallium Arsenide, and thats what everyone sees in the 90's devices. Unknown that these new led/diode are safer for the (GREEN) environment. hmmmm!
Hmm interesting. Perhaps pulsing laser beam will extend diod's life...  I know they use them in the banks, museums, just don't know what kinds smiley
105  Using Arduino / Project Guidance / Re: Laser interrupt sensor on: June 20, 2013, 03:50:43 pm

I like the diode/led , but.. , what happens when the led/diode stops working.

What happens to the user?
Is this a serious question? smiley-grin
I guess depends on the person.  If it's a sane person, he'll contact me for repair exchange it, or just go on with his/her life smiley  We are not talking about life support system here, just an alarm clock smiley
BTW I currently make these clocks, and it just happened that because of the large display, easy to press buttons and vocal announcements of time/date/temperature/alarm settings I was approached by a physically disabled person, so I had few ides on how to modify them to make even more convenient for such people.
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