Hello everyone,
I'm working on a PCB which uses an Atmega2560.
I only have a ISP interface on my pcb ( MISO MOSI SCK ).
With this interface, do i have full acces to the microcontroller?
More specific, can i burn the bootloader over ISP and program the chip over ISP ( last question is yes as far as i know )
I hope to hear soon from you guys, thank you for your help.
You need access to reset also.
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larryd:
You need access to reset also..
So if i use a standard ICSP connection ( MISO MOSI SCK 5V RESET GND ) and a usb to ICSP convertor.
I can burn the bootloader an program the chip over ICSP? is this correct?
Yes, you can program anything, including fuses. An you won't need a bootloader if you always program via ICSP
You just won't have serial port access via USB for debugging.
Hello guys,
Thank you for your support. I'm aware of the fact i won't be able to use the serial monitor. This is no problem for my application ( 27 channel light controller ).
I thought i had to burn the bootloader and use an uno or mega as isp to download my program.
Now i hear i wouldn't need to burn the bootloader, could somebody give me more information about downloading a program to an IC without bootloader? I have neverd heard of something like this?
Thank you for the relpy guys!
Now i hear i wouldn't need to burn the bootloader, could somebody give me more information about downloading a program to an IC without bootloader?
You select "Upload using Programmer" rather than "Upload" in the Sketch menu...
No bootloader needed. The list of possible programmers is in the tools menu.
avr_fred:
You select "Upload using Programmer" rather than "Upload" in the Sketch menu...No bootloader needed. The list of possible programmers is in the tools menu.
Thank you for your input.
Say for instance i have an uno to program mu atmega2560 over ICSP. What settings do i need to use?
Arduino as isp programmer? This is not clear to me?
Select Arduino as ISP
larryd:
Select Arduino as ISP
and how will the programmer know if i'm using a 328p or an 2560?
larryd:
See
https://www.arduino.cc/en/hacking/programmer
Okay i understand most of it.
But this is unclear to me: However you must have in mind that the Upload Using Programmer procedure doesn't burn fuses so
What do they mean by this?
So i'm able to program the chip without bootloader? I think this is the most important to me.
I thought the bootloader was used to give the code a connection to the atmega pins.
So this is not true i guess? So what is the reason the tutorial is still telling me to install the bootloader?
As the bootloader is also loaded over ICSP, what would be the reason to not install the bootloader?
Burning the bootloader sets up the controller fuses, which sets up the controller internals.
Then when you use the upload using programmer, the bootloader is erased but the fuses stay intact.
.
Read this for info on fuses, if you are interested.
http://www.ladyada.net/learn/avr/fuses.html
larryd:
Burning the bootloader sets up the controller fuses, which sets up the controller internals.Then when you use the upload using programmer, the bootloader is erased but the fuses stay intact.
.
So as far as i understand this whole thing.
The fuses are the very basic parameters of the ic?
I guess it would be more easy for me, just to burn the atmega2560 bootloader over ICSP and than program the chip over ICSP? Since i used the same output ports in my PCB as the arduino Mega.
Am i correct on this point?
That's about it.
.
