I've made some shields for the mega that worked out well and would like to put the microcontroller on-board in the next revision. This would be my first gig at removing the arduino from the equation. I've googled around for some pcb/eagle examples but havent found any. Short of reading the 2560 microcontroller data sheets, is there anyone who has done this before or could point me in the right direction? I'm looking for the bare minimum specs to support the 2560 at 5v with only programming pins exposed (usb isn't necessary.)
codlink:
Schematic attached. It includes pin headers, but if you don't need them, you can take them out. This only has the breakout ISCP for programming.
Thanks! It will take me some time to figure out but I think this will do the trick!
I have a question but it's more related to schematic connections in eagle. I've read a bunch and watched several youtube videos but I'm still not getting it right.
I'd like to connect leads from a simple connector (PAD in the attached graphic) to the microcontroller. I'm creating a line using NET and then using LABEL to define it as part of a NET, in this case PF3 (Digital pin 5). When I define the label Net name as PF3 I receive the error "Net name 'PF3' already exists. Use the NAME command to combine nets." So then I use the NAME command and I name it PF3, it then asks me something like 'Connect N$1 and PF3?' and I say yes. Everything looks fine, but when I switch to the board view I see the PAD connector but the line from PF3 doesn't appear.
Delete the Nets and try it again. I have had the problem where the Nets look connected on the schematic but not connected on the PCB. I have to delete the Nets and re-draw them. Somehow, they're really not connected..
Oh, and make sure that both Nets that you want connected have the same name..
Okay, I've moved the connector to find that the NET lines weren't connected to it, now they are. When I go the see the board I get a consistency error which I can see through the ERC error window "Different connections on PAD pin 1 and pad 1 (PF3 / none)"
You can Name a net line, but you need to use the ABC button to actually make it appear, otherwise it is hidden.
I usually go and use ABC on all the lines, so they show up with N$1, N$2, type names, and then right-click & Name them.
codlink:
Schematic attached. It includes pin headers, but if you don't need them, you can take them out. This only has the breakout ISCP for programming.
If you post an image rather than an eagle file then more people will be able to look at your schematic... I've got Eagle but an older version
so I can't see it either!
MarkT:
If you post an image rather than an eagle file then more people will be able to look at your schematic... I've got Eagle but an older version
so I can't see it either!
I don't know why you would want to see mine.. But ok.
Depends on current draw. If really high, may impact the programmer.
Program directly from ICSP. File:Upload Using Programmer (results in no bootloader).
Atmel AVR ISP MKii, $36 at mouser.com. Board must be powered, MKii only monitors the power (unless you hack it to supply power from USB port - I have used just a AA battery pack).
I'll be replacing the 7805 with a more efficient DC-DC boost / step-up circuit. The power will be a pair of AA or AAA batteries. I've looked at the LT1308 (7 parts + IC), as well as the MAX179X series (6 parts + IC) - any recommendations for a high-efficiency low-heat equivalent that uses a minimal amount of parts?
