Atmega64 upgrade daughterboard

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guest
 
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Re: Atmega64 upgrade daughterboard

Post by guest »

i havent looked at the brd file yet
as i need to download eagle to do that
but here are the special function pins
and what they need to be mapped to

atmega162 -> atmega64
pb2 -> pd2 (rx1)
pb3 -> pd3 (tx1)
pb5 -> pb2 (mosi)
pb6 -> pb3 (miso)
pb7 -> pb1 (sck)
rset -> rset (rset)
pd0 -> pe0 (rx0)
pd1 -> pe1 (tx0)
xtl2 -> xtl2 (xtl2)
xtl1 -> xtl1 (xtl1)

it also looks like AVCC might not be connected
its probably worth doing so just in case someone wants to use
the adc section in the future
im also not sure what it does when its not connected

are both VCCs and the three GNDs connected as well

and can you use the spi programming interface
when the chip is connected in the circuit
as there are other bits on the spi pins
Last edited by guest on Sat Dec 06, 2008 8:27 am, edited 1 time in total.

guest
 
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Re: Atmega64 upgrade daughterboard

Post by guest »

does the pen pin have to go the spi interface
or is that an optional thing

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

atmega162 -> atmega64
pb2 -> pd2 (rx1)
pb3 -> pd3 (tx1)
pb5 -> pb2 (mosi)
pb6 -> pb3 (miso)
pb7 -> pb1 (sck)
rset -> rset (rset)
pd0 -> pe0 (rx0)
pd1 -> pe1 (tx0)
xtl2 -> xtl2 (xtl2)
xtl1 -> xtl1 (xtl1)
these are all correct with the exception of PD0 & PD1.I'll re-route those.

All gnds are connected.
AVcc is not connected. easy to do.
does the pen pin have to go the spi interface
or is that an optional thing
I think it's optional I'll take a look.
and can you use the spi programming interface
when the chip is connected in the circuit
as there are other bits on the spi pins
I thought the stuff on PB5-PB7 on the mega162 were just general I/O's so I routed them one-to-one. SPI functions for mega64 are on PB1-PB3 so I just used those. Someone please confirm if PB5-PB7 on the x0xb0x are using speciial functions or just general I/O.

Hazard
 
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Re: Atmega64 upgrade daughterboard

Post by Hazard »

bcbox wrote:
AVcc is not connected. easy to do.
Don't forget ARef and AGnd
bcbox wrote:
does the pen pin have to go the spi interface
or is that an optional thing
I think it's optional I'll take a look.
It is used for memories, along with ale and address pins, x0x doesn't need it.
bcbox wrote:
and can you use the spi programming interface
when the chip is connected in the circuit
as there are other bits on the spi pins
I thought the stuff on PB5-PB7 on the mega162 were just general I/O's so I routed them one-to-one. SPI functions for mega64 are on PB1-PB3 so I just used those. Someone please confirm if PB5-PB7 on the x0xb0x are using speciial functions or just general I/O.
[/quote]
Yes they are, SPI is used to send leds and receive buttons and for the eeprom.
For using the same pins for ICSP and IO, I think it needs resistors in series, with the connection of ISP header directly to the uC pin.

I think you should drop the Xtal on the x0x and place one in the board.
From the brd file I can see at least Vcc pin not connected.

If there was a sch file, it would be easier to analyze the connections

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

Don't forget ARef and AGnd
ok.
PEN...It is used for memories, along with ale and address pins, x0x doesn't need it.
ok.
Yes they are, SPI is used to send leds and receive buttons and for the eeprom.
For using the same pins for ICSP and IO, I think it needs resistors in series, with the connection of ISP header directly to the uC pin.
ok.
I think you should drop the Xtal on the x0x and place one in the board.
I did a version with the xtal on the new board - there's a spot for it just at the bottom right area.
From the brd file I can see at least Vcc pin not connected.
ok
If there was a sch file, it would be easier to analyze the connections
There's no schematic - sketched by hand - but the traces are named to help.

Thanks for the input, these are all the answers I was hoping you guys wouldrespond with.
I will update the pcb later tonight and reply again.

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

I've made the changes so far. I'm heading out for now. The only remaining question I have is if Gate (PE1) and Note Latch (PE2) need to be routed to specific I/O's.

guest
 
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Re: Atmega64 upgrade daughterboard

Post by guest »

im pretty sure that pe1 and pe2
are just regular i/o

Aref may not need to be connected
as i think you can do that internally

the miso line could also use a jumper instead of a resistor
that would help keep the edges sharp
although it would be more of a pain to use

you could make the onboard crystal an option
it might work ok with the long traces

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

All changes are complete

- connected all Vcc, AVcc, Gnd
- re-routed all ports correctly
- added resistors in series with SCK, MOSI, MISO, & RESET to x0x (SPI header goes direct)
- added jumper option for MISO (so can be used instead of resistor)
- added place for xtal as option

I'll post file and pic tomorrow.
Last edited by bcbox on Sun Dec 07, 2008 9:10 am, edited 1 time in total.

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phono
 
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Re: Atmega64 upgrade daughterboard

Post by phono »

this is looking interesting, what sort of advantages can we expect from the daughterboard?

guest
 
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Re: Atmega64 upgrade daughterboard

Post by guest »

you shouldnt need resistors for anything but miso and reset
everything else is an input and doesnt mind being driven

make sure the surface mount sip header
is the lowest profile one you can find

im interested in seeing this thing work

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

download the v3 .brd file here
This has all changes up to this point.

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

this is looking interesting, what sort of advantages can we expect from the daughterboard?
The simple advantage for a stock x0xb0x is more flash, so the firmware can be expanded. I know the sokkOS firmware is at 100% capacity so anytime you want to add a simple function you have to delete something else, etc. As far as modding the x0x further it has more flash and more I/O's so you can add any features you can dream up. The atmega128 has 8x more flash than the current atmega162, and has about 16 more I/O's. I'm thinking about using some additional outputs to send to a simple D/A for dynamic CV control of the filter. Hazard mentioned he was thinking about adding an LCD. Also there is an SPI header so that you have the option to use an AVR programmer like the USBtinyISP to upload firmware. For some reason a lot of people have problems with the USB interface that's designed into the x0xb0x.

bcbox
 
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Re: Atmega64 upgrade daughterboard

Post by bcbox »

Here is the latest board file
I'm going to have some pcb's made. I'll need some people to test them so let me know if you're interested so I can send pcb's when they come in.

Image

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phono
 
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Re: Atmega64 upgrade daughterboard

Post by phono »

bcbox wrote:Here is the latest board file
I'm going to have some pcb's made. I'll need some people to test them so let me know if you're interested so I can send pcb's when they come in.

Image
im interested

guest
 
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Re: Atmega64 upgrade daughterboard

Post by guest »

unfortunately my programming skills arent that sharp
but if you post things to the forum that are being buggy
ill have a look and see what i can come up with

one thing i noticed about the code
is that there are some variables which are defined in multiple places
so be sure to check all files when changing the ports and such

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