Just as an OT comment: I often wonder why NXP offers nothing but M0 chips in DIP or PLCC. The M3 family delivers remarkably better performance - so much so that I can't get enthused about the former. (Clock rates don't tell even half of the story.)
Just as an OT comment: I often wonder why NXP offers nothing but M0 chips in DIP or PLCC. The M3 family delivers remarkably better performance - so much so that I can't get enthused about the former. (Clock rates don't tell even half of the story.)
Good question. DIP packages have to be a niche, and not really that price sensitive, so sensible would be the 'largest die; in SDIP28 and another (larger?) sibling in DIP28 ( or even SO28) - M4 in SDIP28 anyone ?
There has been more than once I settled for a chip that I didn't want, just because it was not available in dip. Adapters can be very expensive, and just like shields, they waste too much space IMO. I have done some amazing things with no resources before, but I'm getting too old for this nonsense. I've been watching the PCB threads and wondering the best way for me to get printing. This is the ONLY way I'll be able to move into SMD like I desire..
The board looks very nice. The one thing I HAVE been wondering. How the heck do you guys do solder mask?
I don't bother with solder-mask. Some people do: film has to be applied and then the process is similar to the actual PCB production, with artwork, UV exposure, etc.
Today I received my order of Press-and-Peel sheets.
I just had to try this out, since the toner transfer from glossy photopaper did not work.
And the result after one hour of mucking about,
I found some etchant and silver plating liquid from about 30 years ago. Still did the job. Not perfect, but acceptable.
Now drilling all those holes should be fun.
@Wa_Mo, thats a really good Press n Peel result. I usually get more pits than that, though it generally works well enough, and its easy to fix any minor breaks.
I've never really optimized the temperature of the iron etc. Perhaps I should invest an hour like you and inject some science into the process...
I don't know if there are different types of Press and Peel available. The sheet which I used was Press and Peel Blue and I just followed the directions which came with the sheets. The important step seems to be the temperature of the iron (ca 300 deg F).
I wonder if the peeled sheet could be reused for a presensitized board.
Setting up my equipment takes about two minutes and involves:
Putting the UV exposure unit on the kitchen table, placing the transparency and sensitised laminate on the glass, plugging it in, and switching it on for the requisite time.
Pouring the developer into the container in the kitchen sink, and adding the exposed laminate.
Pouring very hot water into an old washing up bowl in the kitchen sink, adding the etchant container, pouring the etchant into the container, and adding the laminate.
Putting the equipment away takes about four minutes and involves:
Removing the UV exposure unit from the kitchen table and putting it away.
Pouring the developer back in the bottle and rinsing the container. Putting them away.
Pouring the etchant back in the bottle, rinsing the container and the old washing up bowl. Putting them away.
The developer, etchant, and two plastic containers are kept in the old washing up bowl, and take up very little space. The UV exposure is very compact, also.
The only item I built was the UV exposure unit, it took me about one hour. I could have purchased one quite cheaply.
Everything is done under normal lighting - daylight or artificial lighting. A special table isn't necessary with my process.
Here is my latest PCB, fully assembled. It's a simple prototyping board for the new NXP LPC1114 ARM Cortex-M0 in a DIP28 package. I can't test it properly because the device isn't supported yet by the Rowley CrossWorks ARM tools, and the loader won't work. They are working on it. I can access it via the ARM SWD debug interface, so there can't be anything wrong with the PCB design.
I extracted the chip ID from the LPC1114 using the debug I/F, and Rowley has used it to modify their loader. I was able to test my hardware properly with the new version.
/* Flasher.c
** LED flasher
** LED on PIO1_0 (pin 9)
**
*/
#include <LPC11xx.h>
void delay(void);
int main(void)
{
LPC_IOCON->R_PIO1_0 = 0x0041; // Select PIO1_0, Mode inactive, no hysteresis, ADmode digital, standard GPIO output
LPC_GPIO1->DIR = 0x00000001; // Make PIO1_0 output
LPC_GPIO1->DATA = 0x00000000; // Start with it low
while(1)
{
LPC_GPIO1->DATA = 0x00000000; // LED off
delay(); // Wait a while
LPC_GPIO1->DATA = 0x00000001; // LED on
delay(); // Wait a while
}
return 0;
}
// Delay routine
void delay(void)
{
volatile long i;
for (i = 0; i < 500000; i++)
;
}
ARM's CMSIS - Cortex Microcontroller Software Interface Standard - makes accessing peripheral registers quite straightforward. Cortex peripherals are rather complex, and would otherwise be rather difficult to use.
Comments
Good question. DIP packages have to be a niche, and not really that price sensitive, so sensible would be the 'largest die; in SDIP28 and another (larger?) sibling in DIP28 ( or even SO28) - M4 in SDIP28 anyone ?
Really ? Which 8 bit parts come in Wide Body DIP28 ?
The board looks very nice. The one thing I HAVE been wondering. How the heck do you guys do solder mask?
I just had to try this out, since the toner transfer from glossy photopaper did not work.
And the result after one hour of mucking about,
I found some etchant and silver plating liquid from about 30 years ago. Still did the job. Not perfect, but acceptable.
Now drilling all those holes should be fun.
I've just drilled lots of holes on my latest board.
I've never really optimized the temperature of the iron etc. Perhaps I should invest an hour like you and inject some science into the process...
I wonder if the peeled sheet could be reused for a presensitized board.
Putting the UV exposure unit on the kitchen table, placing the transparency and sensitised laminate on the glass, plugging it in, and switching it on for the requisite time.
Pouring the developer into the container in the kitchen sink, and adding the exposed laminate.
Pouring very hot water into an old washing up bowl in the kitchen sink, adding the etchant container, pouring the etchant into the container, and adding the laminate.
Putting the equipment away takes about four minutes and involves:
Removing the UV exposure unit from the kitchen table and putting it away.
Pouring the developer back in the bottle and rinsing the container. Putting them away.
Pouring the etchant back in the bottle, rinsing the container and the old washing up bowl. Putting them away.
The developer, etchant, and two plastic containers are kept in the old washing up bowl, and take up very little space. The UV exposure is very compact, also.
The only item I built was the UV exposure unit, it took me about one hour. I could have purchased one quite cheaply.
Everything is done under normal lighting - daylight or artificial lighting. A special table isn't necessary with my process.
I extracted the chip ID from the LPC1114 using the debug I/F, and Rowley has used it to modify their loader. I was able to test my hardware properly with the new version.
/* Flasher.c ** LED flasher ** LED on PIO1_0 (pin 9) ** */ #include <LPC11xx.h> void delay(void); int main(void) { LPC_IOCON->R_PIO1_0 = 0x0041; // Select PIO1_0, Mode inactive, no hysteresis, ADmode digital, standard GPIO output LPC_GPIO1->DIR = 0x00000001; // Make PIO1_0 output LPC_GPIO1->DATA = 0x00000000; // Start with it low while(1) { LPC_GPIO1->DATA = 0x00000000; // LED off delay(); // Wait a while LPC_GPIO1->DATA = 0x00000001; // LED on delay(); // Wait a while } return 0; } // Delay routine void delay(void) { volatile long i; for (i = 0; i < 500000; i++) ; }ARM's CMSIS - Cortex Microcontroller Software Interface Standard - makes accessing peripheral registers quite straightforward. Cortex peripherals are rather complex, and would otherwise be rather difficult to use.