[quote author="TomKeddie"]Now that taobao accepts foreign credit cards there is no need to use an agent. [/quote]
I buy about US $250 per month from Taobao plus shipping, that's a sizeable box every month (stock for resale locally), I've been doing this for quite some time now (my spreadsheets say I'm waiting on my 27th order to arrive currently).
I still use an Agent to do it even though here in NZ and AU we've had the ability to buy directly for about a year.
Why do I use an agent? Because of the service, a good agent will communicate with you, and the seller, they will check the items are correct, and deal with getting them corrected if not etc etc.. it's more than just slapping things in a box and shipping them out.
Just got back my first order of dirty pcbs, all up excellent. Anyway, plenty of others have espoused the greatness of dirtypcbs so I won't go into depth, but I haven't previously seen mention of how minimum the silkscreen text sizes can get.
I made some text on my pcbs really quite small, fully expecting it to be a miserable mess, but in fact it's beautifully sharp.
In the text sparks.gogo.co.nz shown below, the width of the lines in the characters is approx 6 mil (approx 0.15mm), this is a "Vector Font Size 4 with Normal line width" in Diptrace. The total height of the letter k is approx 46mil (approx 1.15mm). It is very clear and readable, and looks roughly the same or a bit smaller as the ID number printed by the board house.
FWIW, 5x5 protopack, I lucked out and got 12 boards, all look good, only thing I noticed was a very slight difference in registration between sides (that is, drill hits on one side are perfectly centered by mk 1 eyeball, on the other they are slightly off center, nothing major).
[quote author="ian"]Sometimes the board house only sends 9 (rarely 8) PCBs. Instead of fighting with them and delaying orders, I decided to rename it "protopack +/-10", so you get about ten boards. For twice as much we'll guarantee 10 with a better board house :)[/quote]
Did you know the price for 10, 20 and 30 is all $50?
[quote author="sparkybg"]Soon there will be a new version. The most universal I can think of. [/quote]
Very nice
I don't know that the tab for the USB is a good idea. If it were me, I'd make the board purely rectangular, so that it can just have V grooves to break apart a panel, also mechanically stronger and easier to fit in an enclosure. In fact, I'd look into making the USB just a pcb header connection so you can put a panel mounted USB socket wherever.
I'd advise to test the ADC's independent of other pins, that is, don't feed your ADC from another pin, feed it through a potentiometer and a limiting resistor on the wiper (in case you accidentally put the pin into output low and shove 5v up it with the wiper to the top :-)) and output the values for each pin as you twiddle the pot.
[quote author="Philip"]It seems that not everything on the board/chip works! or i might did something wrong wrong.[/quote]
What doesn't work? If it's brand new, it's VERY unlikely that you have a problem with the device.
That said, when I buy in raw atmega's from China I test a couple at random from the batch for all these functions just using an Arduino sketch, just in case one day I get sent dodgy scraping off the floor of the atmel factory or something :-)
Digital output - check all pins can write high/low Digital input - check all pins can read high/low, both with and without internal pullup active PWM - check all pwm pins can be pwm'd from 0 to 255 and back Analog input - check all analog pins can read a variable voltage (twiddle a pot, check value changes as expected) EEPROM read & write
[quote author="ian"] Not sure how to divide this[/quote]
Passives - resistors, caps. Different packs for each size you will stock.
Discretes - transistors, diodes, mosfets, regulators, polyfuse. A single selection pack, think about the quantities to get a useful mix, somebody does not need as many polyfuses as they do NPNs.
Hardware - plugs, sockets, wires, etc. Perhaps a selection pack. I don't know I'd bother with Mini B and Micro B, just pick one of the other and standardise (Mini B is probably easier to solder).
For what it's worth, you might want to skim this document, it's for a discrete pack I put togethor (and I will say, not a big seller, probably won't be bothering once my last have gone, way too much work assembling each pack): http://283.mytrademe.info/assets/_site_ ... ybeans.pdf
No mosfets? There are a number of SMD logic level mosfets out there for cheap, SI2302DS, AP2305 and of course the 2N7002, SOT-23 fets are almost as cheap as bjt
If you just rack up the reels on a bar fixed to the wall, and have a measuring stick, it would be pretty quick to slice off the appropriate measured length of tape for each reel.
If t'were me, I'd make it a DIY kit, send the tapes, the folder, and printed value stickers, let the customer file the tapes into the folder and stick on the stickers themselves, that's the very time consuming part, cutting the tapes would be a 5 minute job if you've got it setup.
FWIW, I made up my own resistor series (for my own use, I don't bother selling resistors, too much work cutting strips, too little profit).
Anyway, because I'm cheapo, I didn't want a full series, and equally I wanted to choose my own values that would be most useful for hobby purposes, I don't mind using 2-3 resistors to get a close value, or just using the closest one I have.
I also put thought into "useful" values, especially for LED current limiting.
I also don't really like fiddling with strips, so I didn't want a folder of strips.
So anyway, these are the values I came up with: 6 decades each of 1, 1.5, 2.2, 2.7, 3.3, 3.9, 4.7, 5.1 and some extra specific values 120R, 180R, 240R, 300R, 360R, 430R, 1M total 55 values, and I stocked with 100 of each.
I store them in two pill boxes as in the attached. I have 1 compartment left over, 10M might be good there.
Of course, most of the common values are there, 4.7, 2.2... but I use this set along with my resistor paralleler if I need to get something close to a calculated value, generally 2-3 resistors parallel gets well within a percent. I started off with a smaller set (basically skipping out every other value-series) but that made it too difficult to get close values a lot of the time.
[quote author="Sleepwalker3"] Presumably the link I mentioned above is the agent? [/quote]
Navigation on taobao is something of a maze of various domains (not helped by not reading Chinese), here is a link to a decent category listing of the type of stuff we are interested in.
So for example if you wanted to buy an item you found there, you'd copy the URL of the item details page (for example), and paste it into the "Taobao Link / Keywords" field on Bhiner.com (or your other choice of agent), from where you can select quantity, add to cart (for example)....
[quote author="Sleepwalker3"]Presumably Chrome would just use Google translate automatically?[/quote]
Yes, Chrome translates the pages automatically. Chrome doesn't translate what you type into the search fields, you need to do that first (hence using Google Translate from English to Chinese).
[quote author="Sleepwalker3"]You don't actually know how much you are going to pay for freight until after you bought it. [/quote]
The agents have shipping estimators you can use on their sites. From experience, my rule of thumb to NZ (AU would probably be the same) by EMS or Airmail HK is a shipping cost of $0.04 USD per gram of actual product weight. Example if I bought 1 kilogram of 5mm LEDs (which would be about 3300 leds if you wanted to know) I'd budget on paying total about $40 USD international shipping.
[quote author="Sleepwalker3"]BTW, didn't realise you were from CC, hope things are starting to settle and gradually get back to 'normal' over there.[/quote]
Lucky for us we were in a more geologically stable part of the city so was just cosmetic damage for us mostly. One day the insurers will get around to fixing it, or coughing up the money, one day, talk about blood from a stone.
[quote author="Sleepwalker3"]I'm still trying to get my head around how this stuff works, as I understand it, you're paying somebody to act as an agent to go and get this stuff from sellers they deal with in the markets, is that about it? A few people have mentioned paying in two lots which confuses me,[/quote]
Taobao for Dummies 0. Browse Taobao using Google Chrome so it can translate everything for you, use Google Translate to translate your search keywords into simplified chinese, copy and paste into taobao search field. 1. Copy url for the item you want on taobao 2. Paste into agent's website cart system and chooose option, quantity... 3. Repeat as necessary 4. Agent confirms availability of items with the seller, they don't physically go anywhere they just contact the seller in chinese using email, phone, QQ chat.. (not all agents do this step here) 5. You pay the first amount for the products and the domestic shipping from seller to the agent's warehouse, agent buys the goods and has them shipped to their warehouse 6. Agent waits for everything to arrive, some take photos as they do fr you to check online 7. Agent packages everything into a box and weighs it to get the international price for shipping depending on your preferred shipping method 8. You pay the amount for international shipping from agent to you 9. A week or 2 later you receive the package.
The OP appears to have just ripped a bunch of my descriptions of the agents from my original post in March ( viewtopic.php?f=2&t=5278#p51235 ) to up thier post count probably but since it seems to have started some discussion anyway I guess that's OK. The DP forums (and DP in general, A New Open Source Hardware Project Every Month...) is not exactly a hive of activity lately [China seems to have swallowed Ian whole?].
FWIW, I am still currently using Bhiner, on the whole, the service is acceptable, they do have reasonable English (esp if you email), the cart system works most of the time (and works the most correctly of any of the agents), they are fairly quick to quote and buy. However, they can be very slow lately to pack orders once they arrive, your goods might sit in their warehouse for a week or even 2 before they get around to packing them.
They also tried on some funny charges with my last order 2 weeks after it was paid claiming the cart system added wrong, but an email with screenshots I had taken (I take screenshots of all steps in the order process!) showing the cart was correct was enough to get that put right again; so I'll give benefit of the doubt there that they just made a mistake.
I've considered trying a different agent (specifically taobaotrends due to some good reviews about them) because of the recent problems, but..... better the devil you know really, plus they take personal paypal without fees.
Just submitted my latest few hundred bucks worth on Saturday, Taobao order #12, 1 a month.
Another good place to get info about taobao agents is, of all places, 4chan, specifically the "cgl" board (I'm not not into cgl, but those who are buy lots of their stuff from taobao), they call agents "Shopping Services" over there.
[quote author="spanner888"]A few minutes later got a phone call [/quote]
Are you using an agent or dealing direct? I've yet to find an agent that actually up-front gives any current promotional price, most seem to just give you the normal retail price and I assume pocket the difference. Not that most promotional prices on TB are any great discount.
