James Moxham (Dr_Acula)
2013-12-11 12:06:45 UTC
Inspired by John Coffman's superb single board design, I thought I would
also delve into a 4 layer PCB. Initial research with Seeed Studios suggest
that a 4 layer PCB of 100x160mm is only $10 more than a 2 layer PCB (for 5
boards, so $2 extra per board), so I thought I would run a design through
Eagle PCB's autorouter and see how it went. The conclusion of the
experiment is that 4 layers routes much quicker than 2 layers, and that
there are significantly less vias on a typical board (150 vs 500). Also, it
is possible to place the chips much closer, and hence pack a lot more
components onto a board.
So the challenge was to take the Prop I/O board and the standard Z80 sbc v2
board and try to merge them together.
There were a few compromises. Sadly, there was not room for the 8255 PIO.
But on the other hand, so many more goodies on the board. These are the
specifications:
* On board switching regulators (3V and 5V)
* Run from a wall wart 9V to 20V with only a few hundred mA current
consumption - no special supply needed
* 74HC chips so all chips run cool/cold
* No EPROM - saves on having to buy a pre programmed chip or a programmer
* Serial port with baud rates up to 115200 and higher
* SD card - gigabytes of storage
* TV output or VGA output. Use small 7" 'car reversing' TV screens or a
standard VGA monitor
* Keyboard
* Audio output (play .WAV files directly from the SD card)
* 512k ram
* ECB bus interface
* header for I2C bus for RTC, analog/digitial I/O etc
* buffered Keyboard/Serial Port I/O so Z80 is not tied up polling for input
data
* Program the propeller with a standard USB to Serial cable
I think this may be a useful single board design and I'm thinking of
getting some boards made. Thoughts/criticisms/ideas would be most
appreciated.
Cheers, James Moxham
--
You received this message because you are subscribed to the Google Groups "N8VEM" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/***@public.gmane.org
To post to this group, send email to n8vem-/JYPxA39Uh5TLH3MbocFF+G/***@public.gmane.org
Visit this group at http://groups.google.com/group/n8vem.
For more options, visit https://groups.google.com/groups/opt_out.
also delve into a 4 layer PCB. Initial research with Seeed Studios suggest
that a 4 layer PCB of 100x160mm is only $10 more than a 2 layer PCB (for 5
boards, so $2 extra per board), so I thought I would run a design through
Eagle PCB's autorouter and see how it went. The conclusion of the
experiment is that 4 layers routes much quicker than 2 layers, and that
there are significantly less vias on a typical board (150 vs 500). Also, it
is possible to place the chips much closer, and hence pack a lot more
components onto a board.
So the challenge was to take the Prop I/O board and the standard Z80 sbc v2
board and try to merge them together.
There were a few compromises. Sadly, there was not room for the 8255 PIO.
But on the other hand, so many more goodies on the board. These are the
specifications:
* On board switching regulators (3V and 5V)
* Run from a wall wart 9V to 20V with only a few hundred mA current
consumption - no special supply needed
* 74HC chips so all chips run cool/cold
* No EPROM - saves on having to buy a pre programmed chip or a programmer
* Serial port with baud rates up to 115200 and higher
* SD card - gigabytes of storage
* TV output or VGA output. Use small 7" 'car reversing' TV screens or a
standard VGA monitor
* Keyboard
* Audio output (play .WAV files directly from the SD card)
* 512k ram
* ECB bus interface
* header for I2C bus for RTC, analog/digitial I/O etc
* buffered Keyboard/Serial Port I/O so Z80 is not tied up polling for input
data
* Program the propeller with a standard USB to Serial cable
I think this may be a useful single board design and I'm thinking of
getting some boards made. Thoughts/criticisms/ideas would be most
appreciated.
Cheers, James Moxham
--
You received this message because you are subscribed to the Google Groups "N8VEM" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/***@public.gmane.org
To post to this group, send email to n8vem-/JYPxA39Uh5TLH3MbocFF+G/***@public.gmane.org
Visit this group at http://groups.google.com/group/n8vem.
For more options, visit https://groups.google.com/groups/opt_out.