Buying target boards alone?

lpcware · ‎06-15-2016

Content originally posted in LPCWare by akhilpo on Wed May 18 03:17:51 MST 2011
Is it possible to buy the 'target board' of the xpresso kit alone? If not is there any similar alternative? Something like a board with just a MCU and its pins mapped to headers. So that hobbyists like me can reduce the project cost to minimum.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by larryvc on Thu Jun 02 12:39:47 MST 2011

Quote: Rob65

I mean one of these boards with a lot of round holes and copper around each hole.

http://en.wikipedia.org/wiki/Perfboard

http://knowledgebase.nxp.com/showpost.php?p=8101&postcount=37

http://en.wikipedia.org/wiki/Breadboard

Quote: Rob65
I never throw away stuff. The copper wire is recycled from old small signal transformers. Enough to take me into the next century :D

The copper will probably fund most of your retirement too.:D

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Rob65 on Thu Jun 02 12:27:57 MST 2011

Quote: larryvc
Parallel rows of pins with different functions on adjacent pins on a breadboard?:confused:

This is where I have to admit that my english skills are lacking ...
I mean one of these boards with a lot of round holes and copper around each hole.

Together with thin enamel copper wire (I think it's not enamel anymore but some kind of resin/lacquer) these are the most versatile tools for creating a prototype: just solder the components on the board and then trace your circuit with the copper wire. The lacquer automagically disappears while soldering the wire.

I never throw away stuff. The copper wire is recycled from old small signal transformers. Enough to take me into the next century :D

Rob

lpcware · ‎06-15-2016

Content originally posted in LPCWare by rmteo on Thu Jun 02 11:50:02 MST 2011

Quote: Rob65
There is cheap stuff and there is good stuff.
You will not get a good TFT LCD for that price. They lack brightness, contrast, viewing angle, have too many bad pixels or something else. I have a whole moving box full of those cheap boards that I would happily swap for one or two proper boards :eek:

Rob

Really. Why would would one want to accumulate a whole box full of junk?

lpcware · ‎06-15-2016

Content originally posted in LPCWare by larryvc on Thu Jun 02 11:32:55 MST 2011

Quote: Rob65
all pin headers and holes on a 0.1" grid for easy mounting on a breadboard

Parallel rows of pins with different functions on adjacent pins on a breadboard?:confused:

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Rob65 on Thu Jun 02 11:16:12 MST 2011

Quote: rmteo
That should be easily doable. You can get similar stuff on the auction sites that include a 320x240 TFT LCD and touch screen for around US$40 (<28 Euro).

There is cheap stuff and there is good stuff.
You will not get a good TFT LCD for that price. They lack brightness, contrast, viewing angle, have too many bad pixels or something else. I have a whole moving box full of those cheap boards that I would happily swap for one or two proper boards :eek:
The question was for a board that enables you to create your own projects - not buy a complete subsystem that someone else created...

Start comparing prices and you will find that the boards you mention are almost as cheap/expensive as the minimalistic target boards.

I Just finished my board layout:
[IMG]http://bikealive.nl/img-for-others/LPCXpresso-forum/lpc1754-target-sm.png[/IMG]

[LIST]
[*]Board size 50x70 mm
[*]all pin headers and holes on a 0.1" grid for easy mounting on a breadboard
[*]micro SD slot and CR2032 battery holder on top side of the board
[*]option for mounting I2C EEPROM (24lc08 or 24lc32 style) with pull-up resistors.
Using 50 mil pitch and 0805 resistors so everyone can solder these by hand
[*]No LEDs, no switches, nothing else on the board.
when SD and USB are not used there is nothing connected to the IO pins.
[*]All IO pins named on the silk screen for easy prototyping.
[/LIST]
This makes it the ideal prototyping target board for me. USB and EEPROM are peripherals I make heavily use of in my applications and sometimes SD for storing large volumes of data. Having these on my target board allows me to use standard 100 mil breadboard PCBs and skip the difficult task of wiring those by hand.

Phew ... almost done checking the board, never trust libraries that you receive from others (I still found a few mistakes). Now it's time to ship the stuff to the PCB prototyper for the first 10 boards :D

Rob

lpcware · ‎06-15-2016

Content originally posted in LPCWare by rmteo on Wed Jun 01 17:09:42 MST 2011

Quote: Rob65
For the stripped down version with lpc1754.
So that's a bare minimum 'application board' with processor, crystals, 3.3V LDO, micro-SD, USB (mini-B) and a clip for a CR2032 battery.

Rob

That should be easily doable. You can get similar stuff on the auction sites that include a 320x240 TFT LCD and touch screen for around US$40 (<28 Euro).

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Rob65 on Wed Jun 01 16:27:19 MST 2011

Quote: rmteo
For the full or the stripped down version?

For the stripped down version with lpc1754.
So that's a bare minimum 'application board' with processor, crystals, 3.3V LDO, micro-SD, USB (mini-B) and a clip for a CR2032 battery.

Board dimensions are 70 x 43 mm (just a bit wider than the target section of an LPCXpresso board) but I need to see if that's big enough to still have enough space for labels with all the IOs.
Attached is a picture of the board in progress.

The lpc has decoupling caps on all power pins placed on the bottom of the board close to the Vdd pins. USB and micro-SD slot are placed on top of the board but this unfortunately leaves only room for the battery on the bottom of the board but since this battery holder is a through hole version I always have the option to leave it off and only mount it when needed.

I am still thinking of adding an I2C EEPROM (24LC08 / 24LC32), most of my design now include one of these to store parameter data.

Rob

lpcware · ‎06-15-2016

Content originally posted in LPCWare by rmteo on Wed Jun 01 08:42:08 MST 2011

Quote: Rob65
....I think a price of € 25,- is a fair price for which I could sell these board.

Rob

For the full or the stripped down version?

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Rob65 on Wed Jun 01 02:24:08 MST 2011

Quote: bgeci
2sq" SMT PCB
...
Is this possible ???

Yes, this is possible for a bare minimum design like this.
I'm currently working on an lpc1754 design:

[LIST]
[*]lpc1754
[*]mini USB with ESD protection
[*]Power supply with 5V regulator (the application uses a rechargeable, customer supplied, battery) and 3.3V LDO
[*]12 MHz xtal and 32 kHz xtal for RTC
[*]128x64 transflective LCD (44x22 mm viewing area)
[*]3 high power LED regulators (for 1/3/10W LED)
[*]4 mosfet open drain PWM outputs (used for 1W LEDs that are only used as indicators)
[*]Micro-SD connector or 32 Mbit on-board SPI Flash
[*]optional 1kBit/8kBit I2C EEPROM
[/LIST]

I have been thinking of creating a stripped down version to start development:

[LIST]
[*]lpc1754
[*]3.3V regulator on board
[*]mini USB with ESD protection
[*]micro SD connector (to be used for semi-fixed internal micro-SD, hinge type connector, like a SIM card in a mobile phone - see attached picture)
[*]battery holder for CR2032 to supply RTC
[*]SMD pads for 24LC08 or similar style I2C EEPROM
[*]all I/O accesible through 0.1" holes for mounting pin headers.
[*]low profile design, total height ~7mm max.
[/LIST]
I think a price of € 25,- is a fair price for which I could sell these board.
Please do remember that there is no LPC-Link or ISP port on board, you need a separate 3.3V/5V uart or jtag programmer.

As already stated: the price of the LPCXpresso boards is a very nice price that is hard to beat (but then, the target side has a fairly minimalistic design)

Rob

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Luis Digital on Tue May 31 19:44:04 MST 2011
Have you seen the shipping costs? It's huge!

lpcware · ‎06-15-2016

Content originally posted in LPCWare by bgeci on Tue May 31 17:34:04 MST 2011
2sq" SMT PCB
Soldered:
          ARM LPC1xxx
          XTAL 12 Mhz
          mini USB connector
          couple R,C SMDs
          Pow. supply
0.05" pads around board for SMT soldering (100 pads => 2" x 1" board)

option    jtag SMT 2x10pin 0.1"
          or some mini JTAG connector with extra adapter?

              < 2" 40pads >
   .............../   /.......
   |                          :
   | mini                     : ^
     USB ARM, XTAL, RCs, Pow ~ 1" 20 pads
   |                          :
   ............../   /........

Target price 10$/board in 100 boards order

Is this possible ???

http://www.aliexpress.com/product-fm/320694963-LPC1768-Mini-Board-wholesalers.html

lpcware · ‎06-15-2016

Content originally posted in LPCWare by larryvc on Mon May 23 11:12:56 MST 2011

Quote: jharwood

Position the chip accurately first by soldering just one corner pin. Make sure that it is in perfect register with the lands on all four sides. Don't worry if you hit a few pins in one corner.

I have used a very tiny amount of medium setting super glue in the center of the part to aid in registering the part leads on all the lands. The key is to use a very tiny amount and not get any on the part leads.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Ex-Zero on Mon May 23 01:47:07 MST 2011
There are a lot of informative videos:

http://www.youtube.com/watch?v=NALwJ6OnwNw&feature=related

http://www.youtube.com/watch?v=eg2hxpy--gg&feature=related

lpcware · ‎06-15-2016

Content originally posted in LPCWare by jharwood on Sun May 22 19:47:06 MST 2011

Quote: akhilpo
If I buy LQFP adapters and chip separately and solder it myself, is it possible to bring the price down to 10$?

Quite likely.

Quote:
How tough is soldering LQFP package? Anybody got experience? I haven't done such precise soldering job before.

It's not too difficult. You need soldering flux, desoldering braid (aka solder wick), perhaps a magnifying glass, and good lighting. Patience and a steady hand helps too.

Position the chip accurately first by soldering just one corner pin. Make sure that it is in perfect register with the lands on all four sides. Don't worry if you hit a few pins in one corner.

Apply some flux, then solder the rest of the pins. Don't worry if some of them get bridged with solder. Dip the braid/wick in flux and apply it with the iron onto the pins. It should soak up all the excess solder.

Finally clean the board of excess flux residue. If the flux is water soluble, just use clean warm water (no detergent) and a clean, short-bristle brush. Leave out in the sun to dry.

Otherwise, use 99% Iso-Propyl Alchohol and short-bristle brush and let air dry naturally.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by akhilpo on Sun May 22 19:06:46 MST 2011
If I buy LQFP adapters and chip separately and solder it myself, is it possible to bring the price down to 10$? How tough is soldering LQFP package? Anybody got experience? I haven't done such precise soldering job before. I think its time to learn and move on.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by larryvc on Sun May 22 16:29:21 MST 2011

Quote: jstratmann
I think the 20€ boards from EA are really great stuff also for interested students. Is it only a limited promotion action or is it a long term offer?

This price has been fairly stable and has actually gone down a bit if I recall correctly.

Quote: jstratmann
One disadvantage for semi professionals is the worse availability compared to Atmel components. But using the EA lpc boards look like a smart solution like a little bigger DIP uC.

Just slightly larger than one of these and a lot more capable:

lpcware · ‎06-15-2016

Content originally posted in LPCWare by JojoS on Sun May 22 14:41:30 MST 2011
I think the 20€ boards from EA are really great stuff also for interested students. Is it only a limited promotion action or is it a long term offer? One disadvantage for semi professionals is the worse availability compared to Atmel components. But using the EA lpc boards look like a smart solution like a little bigger DIP uC.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by larryvc on Sun May 22 08:06:18 MST 2011

Quote: Zero
Why not? I know a lot of hobbyists who can etch simple 2 layer PCBs with LQFP100 (LPC1769).

There are even descriptions on YouTube :eek:

Quote: Rob65

It is perfectly possible to create a PCB on which you can solder an lpc1114 or 1343 that works similar to the lqfp48 adapter - or just buy one of these adapter boards.

Quote: domen
I've used these lqfp48 adapters with success:
http://dipmicro.com/store/PCB-LQFP48-DIP48G

akhilpo,

OK, what you are looking for may not be manufactured by anybody yet. So like other hobbyists you will have to learn some more skills. eg. soldering, board design, etching of boards etc...

You need to step back for a moment and look at the costs of doing all these steps to produce a board. I think you will find that the cost is much higher than your initial estimate.

Perhaps domen could post a picture or two of his work with the adapter that he mentioned. That certainly is a feasible solution from a cost standpoint to start out with.

Complaining and arguing will get you nowhere, you have to do something to accomplish your goal or pay someone to do it for you.

That is the point.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Rob65 on Sun May 22 01:42:47 MST 2011

Quote: akhilpo
You missed the point...:(

Yup, never compare apples and oranges :rolleyes:

The point was to "reduce the project costs to a minimum".
The question is what kind of solution would work for you - and others.

[LIST]
[*]Would you be willing/able to spend an hour or so soldering the SMD components yourself?
[*]Do you want to select your own parts vendor or do you accept higher costs for a complete package deal (where one company would provide both the PCB and all the components for you to assemble) ?
[*]If you cannot/willnot assemble yourself, are you okay with a board that has just gone through basic testing (e.g. Blinky works) ?
Or do you want a fully tested board where all I/O signals are tested?
[*]What price level are you looking at?
I think it is almost impossible to deliver a complete solution below the € 15,- mark
[/LIST]
I even think the € 20,- price for the LPCXpresso board is a mega-deal.
You get a target board plus the LPC-Link debugger pod. A PICkit-3 is already € 35,-

But never ever try to compare an lpc1114 with 32 kB program memory and 8 kB RAM with a PIC16F84 with 1 kWords of program memory ...

Rob

lpcware · ‎06-15-2016

Content originally posted in LPCWare by akhilpo on Sun May 22 00:29:45 MST 2011

Quote:
Another interesting tidbit for you. Although APPLE is not the largest cell phone manufacturer - it shipped 18.8 million units in Q1 2011 compared to 108.5 million units shipped by Nokia - in terms of revenue it is bigger. For the same period, APPLE's revenues was US11.9b compared to US$9.4b for Nokia. This is due to the fact that APPLE's average wholesale handset price is US$638 vs. US$87 for Nokia.

You missed the point...:(