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Pittsburgh, PA, USA
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Just got a partial shipment on what may be my last order from DX (DealeXtreme).
Got 50 40-pin header strips (steel, not brass pins), 10 keychain SD-micro/USB adapters and 3 IR signal receivers and a bag of jumpers. Still waiting on 10 2 mW laser modules (because at 45 cents ea, I'll make a use), 10 snap-in RJ-11 modular jacks, and 2 female-female 40 cm DuPont cables.

Well, I might order disc batteries from them but I can't say about that either.
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Left Coast, CA (USA)
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24, yes 24 bit ADC module for less then $10. Let me count the bits, 1,2,3...yes 24 bits in all. So no need to have to amplify externally how level Wheatstone bridge type sensors, just read the millivolts, hell microvolts directly and still have more resolution then arduino's wimpy 10 bit ADC has.

 We will have to see how the low noise performance of this module ends up with, as usually in the real world it's nearly impossible to actually be able to fully utilize 24 bits of resolution.

http://www.ebay.com/itm/121022291106?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Lefty
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Let me count the bits, 1,2,3...yes 24 bits in all.

Now count the possible combinations.  I will get you started...

00000000 00000000 00000000
00000000 00000000 00000001
00000000 00000000 00000010
00000000 00000000 00000011
00000000 00000000 00000100

Go!

 smiley-twist
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I ordered three boards from OSHPark.  Two are Silego breakout boards that I may or may not be able to solder, and one is an FTDI FT230x-based USB/Serial converter.

I'm also thinking about an FTDI VNC2-based "minishield" (USB Host), and an 8051 mini-system (But Why???), but those are aimed at Seeed/Itead (~50mm sq)
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Have you testrun your INO file today?
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http://dx.com/p/diy-10x120mm-3w-270lm-3200k-warm-white-rectangle-light-strip-white-orange-dc-12-13v-191321
http://dx.com/p/diy-5w-14v-3300k-475lm-warm-white-light-cob-led-rectangle-strip-white-yellow-186201
Just one of each, so I wont be making a LED cube of them smiley
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Got one of CrossRoads' ATMega1284P Duemilanova-style boards. Soldered the parts on yesterday (except the FTDI header because I've ordered a USB board to go there).

The SMD soldering is challenging (that fuse kept escaping!), and I had trouble getting the voltage regulators soldered onto the heat sinks. Still, looks good, works fine. smiley


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Got one of CrossRoads' ATMega1284P Duemilanova-style boards. Soldered the parts on yesterday (except the FTDI header because I've ordered a USB board to go there).

The SMD soldering is challenging (that fuse kept escaping!), and I had trouble getting the voltage regulators soldered onto the heat sinks. Still, looks good, works fine. smiley




Lookin' good. I bought two of those blank PCB when Bob made them available. Built just one up so far and real happy with it. I didn't mount any regulators to mine yet, just jumpered Vcc to the DC jack and plug a regulated +5vdc to it. I'm using one of those cheap Asian CP2101 serial cables and it works fine.

 Be sure to make the the small change to the bubuino variant file: pins_arduino.h or the pin mapping for the analog pins will be wrong:

Code:
// #define analogPinToChannel(p)    ( (p) < NUM_ANALOG_INPUTS ? NUM_ANALOG_INPUTS - (p) : -1 )
#define analogPinToChannel(p)       ( (p) < NUM_ANALOG_INPUTS ? (NUM_ANALOG_INPUTS-1) - (p) : -1 )

 Might be a few other changes to the maniac supplied files, I don't recall at the moment.

EDIT: Some people were having reliability problems with the serial port working on the 1284P DIP (but not on bobuino boards!) and lots of different fixes were tried to different effectiveness, but what seemed to nail it for experiencing such problems is changing the low fuse byte to use full swing oscillator: bobuino.bootloader.low_fuses=0xf7
So probably a good change to make on general purposes.

EDIT2: By the way getting a 644P working on this board is a piece of cake just add new board entry:

Quote
##############################################################


bobuino644.name=Bobuino 644P optiboot
bobuino644.upload.protocol=arduino
bobuino644.upload.maximum_size=63488
bobuino644.upload.speed=115200
bobuino644.bootloader.low_fuses=0xff
bobuino644.bootloader.high_fuses=0xdc
bobuino644.bootloader.extended_fuses=0xfd
bobuino644.bootloader.path=optiboot
bobuino644.bootloader.file=optiboot_atmega644p-4-5.hex
bobuino644.bootloader.unlock_bits=0x3F
bobuino644.bootloader.lock_bits=0x0F
bobuino644.build.mcu=atmega644p
bobuino644.build.f_cpu=16000000L
#bobuino644.build.core=arduino:arduino
bobuino644.build.core=standard
bobuino644.build.variant=bobuino

##############################################################

And here is a optibootloader setup for the 644P: optiboot_atmega644p-4-5.hex

Code:
:020000000504F5
:10FC0000112484B714BE81FFF2D085E08093810077
:10FC100082E08093C00088E18093C10086E08093F9
:10FC2000C20080E18093C4008EE0CBD0209A86E0B1
:10FC300020E33CEF91E0309385002093840096BB55
:10FC4000B09BFECF189AA8958150A9F7CC24DD244B
:10FC500088248394B5E0AB2EA1E19A2EF3E0BF2E69
:10FC6000A4D0813471F4A1D0082FB1D0023811F49E
:10FC700085E005C0013811F484E001C083E08DD037
:10FC800089C0823411F484E103C0853419F485E01D
:10FC9000A6D080C0853579F488D0E82EFF2485D0A1
:10FCA000082F10E0102F00270E291F29000F111F09
:10FCB0008ED068016FC0863521F484E090D080E05A
:10FCC000DECF843609F040C070D06FD0082F6DD0E1
:10FCD00080E0C81680EED80618F4F601B7BEE895A5
:10FCE000C0E0D1E062D089930C17E1F7F0E0CF16C5
:10FCF000F0EEDF0618F0F601B7BEE89568D007B65B
:10FD000000FCFDCFA601A0E0B1E02C9130E01196FF
:10FD10008C91119790E0982F8827822B932B129625
:10FD2000FA010C0187BEE89511244E5F5F4FF2E0A7
:10FD3000A030BF0751F7F601A7BEE89507B600FC53
:10FD4000FDCF97BEE89526C08437B1F42ED02DD0D4
:10FD5000F82E2BD03CD0F601EF2C8F010F5F1F4FF8
:10FD600084911BD0EA94F801C1F70894C11CD11CFE
:10FD7000FA94CF0CD11C0EC0853739F428D08EE10F
:10FD80000CD086E90AD08AE07ACF813511F488E078
:10FD900018D01DD080E101D063CF982F8091C00092
:10FDA00085FFFCCF9093C60008958091C00087FF27
:10FDB000FCCF8091C00084FD01C0A8958091C60051
:10FDC0000895E0E6F0E098E1908380830895EDDF08
:10FDD000803219F088E0F5DFFFCF84E1DECF1F939A
:10FDE000182FE3DF1150E9F7F2DF1F91089580E04B
:08FDF000E8DFEE27FF2709946C
:040000030000FC00FD
:00000001FF


Lefty
« Last Edit: March 12, 2013, 08:17:04 pm by retrolefty » Logged

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I bought a few of these for $8:

http://www.ebay.com.au/itm/261132296135

MAX7219 chip plus a 8x8 LED plus PCB (not assembled).



The MAX7219 alone is around $19 for one from Farnell. OK, it's $8 if you buy 100.

But this kit includes the 64-LED display as well! And the circuit board. And two capacitors and a resistor. And the edge connectors. And the chip socket. And socket strips for the LED display.

They are designed to be daisy-chained (haven't quite got that sorted yet).
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Be sure to make the the small change to the bubuino variant file: pins_arduino.h or the pin mapping for the analog pins will be wrong:

Code:
// #define analogPinToChannel(p)    ( (p) < NUM_ANALOG_INPUTS ? NUM_ANALOG_INPUTS - (p) : -1 )
#define analogPinToChannel(p)       ( (p) < NUM_ANALOG_INPUTS ? (NUM_ANALOG_INPUTS-1) - (p) : -1 )

 Might be a few other changes to the maniac supplied files, I don't recall at the moment.

EDIT: Some people were having reliability problems with the serial port working on the 1284P DIP (but not on bobuino boards!) and lots of different fixes were tried to different effectiveness, but what seemed to nail it for experiencing such problems is changing the low fuse byte to use full swing oscillator: bobuino.bootloader.low_fuses=0xf7
So probably a good change to make on general purposes.

Thanks for the suggestions.
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Over the past weekend I went to a local hamfest and picked up a Heathkit ET-3400; it's basically a small 8-bit (Motorola 6800) computer with 512 bytes of memory, some LEDs, a hex keyboard (and 7-segment hex display), ROM monitor software (so you can enter assembler opcodes, and debug, etc) - plus a breadboarding area (which a previous owner had set up a 6821 PIA interface). Also got the manuals for it...

I spent $50.00 for it; Yeah - I could've gotten a Raspberry Pi or a Mega for cheaper - but I can guarantee you neither would be as cool as this monstrosity...hehehe.

smiley-grin
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Quote
picked up a Heathkit ET-3400;

Back in the day I had a Micro Professor which was a similar thing for the Z80 (Z80-based CP/M machines were in vogue). I got a few extras for it, like a Tiny-Basic chip.

Bloody thing got stolen from my office while I was on leave...
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Look here http://electronicsclub.info/ for basic electronics

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The MAX7219 alone is around $19 for one from Farnell. OK, it's $8 if you buy 100.


http://www.ebay.com/itm/250828820487


10 pcs MAX7219CNG -                                                                            $4.80, free shipping.

Just sent an order to them, also got:

2PCS Arduino NRF24L01+ Wireless Transceiver Module                            $2.60
10PCS OPTOCOUPLERS FAIRCHILD/MOTOROLA DIP-6 MOC3041                 $3.79
1 Channel Isolated 5V Relay Module                                                        $2.18
1PCS IC ATMEL DIP-28 ATMEGA328-PU                                                     $3.99 (this is a little high)

and a couple other doodads.. however, when I saw that price you said for 7219's, I figured you may want to snap a few of these up!
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When the testing is complete there will be... cake.

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This is just getting insane. I wonder if they work?

Anyway just ordered 20 for under $10 including free shipping.
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I've ordered so-cheap-its-unbelievable chips from these China sellers. I got some MSGEQ7s

All of them have issues. Some do not work at all. Some work, then fail after some time. They seem like factory rejects... chips that fail QA testing, or not up to par with the published specs.

For personal use, I guess it's okay to gamble with chips from China ebay sellers. But if you're planning on selling your finished product to others, I'd avoid these chinese suppliers that sell chips lower than their retail prices.
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Well, I'm well-known for my bottom-feeding on ebay.. and if the device being made was critical in any way, I would use "real" parts purchased from a reputable retailer.. but in reality, almost none of my projects are something I would directly sell or depend upon for any real purpose.  I will buy "as-is" and "NOS" as a priority, knowing the risks.  The fact is, I feel more comfortable buying from a Shenzen seller with twenty thousand sales on ebay than I do with a Los Angeles seller with sixty sales.. I trust the Shenzen volume seller to care about their reputation more than the new account from California.

In the years I have been grabbing ebay dregs, I only once have gotten trash- a four pack of ATMEGA88's that wouldn't do a thing- and the seller refunded.  

"polida" (the vendor for this particular deal) is one that I have bought a number of things from- and if you don't need customer service (language barrier) I haven't had any problems with and tends to ship pretty quickly.  I think their angle is sheer volume, if you look at their total number of customers it's in the tens of thousands.  

Happily, most of these vendors seem to know their customers are going to be hobbyists and the like- they tend to have a lot of the stuff we tend to buy.  Modules of various types (sensors, voltage regulators, SD card, ethernet, etc) can be ridiculously cheap- I have gotten ethernet modules for $3, Bluetooth for $2, and stepper motor controller (ULN2003) plus stepper motor for $3.  Outside of the modules, you can always bottom feed on certain items- 2N3904/3906 transistors, ULN2003A Darlington Arrays, LED's of all types, MOSFET's, and a dozen different "uino" clones.  I had to dedicate my "real" Arduino Duemilanove to a project for a couple months, so I decided to give (reference to counterfeit product removed by moderator) a try.. they are one of the larger clone outfits.  Their prices are hard to beat also, I got a Uno clone, a Proto Shield with 65 jumpers and a mini breadboard, and an LCD keypad (looks suspiciously like liudr's design) shield... all of it for $39 shipped.  It's coming from California, so shipping isn't even the couple of weeks of waiting that ordering from China is.. it's just the normal 2-3 days for mail.  Today, I am making a 24-channel PWM controller (8 channels of RGB) using AT90S4414.. I bought two TUBES (twenty MCU's, 40-pin AVRs) for $7 TOTAL a while back (I just realized to myself that amounts to just over a penny per GPIO pin!).  I have been planning to using them to make  quick and dirty SPI-to-1602 LCD interfaces, should work great for the purpose.  I am still looking for a good use for the half tube of Dallas 12887+ clocks I bought for TWO BUCKS also.  Yes, I know all of these components are likely to be factory seconds or overstocks- but as I said- in several years and dozens of purchases, only ONE has ever been outright bad.  One thing is for sure-  the vendors take take "Feedback" very seriously and will bend over backwards even on a deal to avoid getting bad feedback, it seems.  I wouldn't try to "take advantage" of that, but it does seem they care about those stars a lot.  

I will give a report on the (reference to counterfeit product removed by moderator) "uino" when it arrives- but I see no reason for it to be anything other than a good ole basic Uno..
« Last Edit: March 13, 2013, 02:30:09 pm by focalist » Logged

When the testing is complete there will be... cake.

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