EastRising LCD used for project

Hi,

I am attempting to create a standalone project using an atmega2560 and a board that uses an RA8875 graphics controller. I have successfully created a piece of working software and have tested it with my arduino mega. I know this code works and I have ripped it using avr studio and saved it to a hex file. When I burn it to a new atmega2560 chip and try to run the display using the SPI bus it does not work. I have ensured all of the fuses are set the way the arduino mega is supposed to be, and have verified that the hex file does indeed work. Is there something I am missing that is done with the mega in order to make the SPI bus function with a standalone chip?

Thanks.

codedsteele: Hi,

I am attempting to create a standalone project using an atmega2560 and a board that uses an RA8875 graphics controller. I have successfully created a piece of working software and have tested it with my arduino mega. I know this code works and I have ripped it using avr studio and saved it to a hex file. When I burn it to a new atmega2560 chip and try to run the display using the SPI bus it does not work. I have ensured all of the fuses are set the way the arduino mega is supposed to be, and have verified that the hex file does indeed work. Is there something I am missing that is done with the mega in order to make the SPI bus function with a standalone chip?

Thanks.

What is your clock, reset circuit?

I have only had one problem with a custom 2560 board, I had a sdcard attached to the SPI bus while programming, the SDcard caused a avrisp500v2 to hang based on the bit stream.

I have used both Arduino(processing) and 6.2 to generate hex files, both work.

Chuck.

I am programming this using a avr isp mkii and connecting to the chip using a zif socket. Atmel studio says the device programming is successful so it can read the chip. My clock circuit consists of a 16 MHZ crystal and 2 22 pf capacitors. All of the vcc pins and avcc pin are connected as well as all ground pins. The reset circuit has nothing attached as I am just programming and testing. I have no other capacitors connected other than the 2 22pf capacitors and also no 10k pull up on reset. From my experience these are recommended but not necessary (they are included on my pcb but not in my test and programming setup). I am confident adding that hardware will probably not fix my problem. There has got to be something obvious I am missing.

10K pullup resistor is needed 0.1uF cap on each VCC/AVCC pin is needed. How is the part powered? MKii only monitors power, it does not provide power unless you have hacked the MKii to do so.

I am using external power, if I wasn't I would not have even been able to program the chip, but I was successful in doing so. I will add the 10Ks and the 0.1 ufs and get back to you, but I am confident this will not fix my problem.

codedsteele:
I am programming this using a avr isp mkii and connecting to the chip using a zif socket. Atmel studio says the device programming is successful so it can read the chip. My clock circuit consists of a 16 MHZ crystal and 2 22 pf capacitors. All of the vcc pins and avcc pin are connected as well as all ground pins. The reset circuit has nothing attached as I am just programming and testing. I have no other capacitors connected other than the 2 22pf capacitors and also no 10k pull up on reset. From my experience these are recommended but not necessary (they are included on my pcb but not in my test and programming setup). I am confident adding that hardware will probably not fix my problem. There has got to be something obvious I am missing.

Do a voltage reading on the Reset pin, I have seen some on the 2560, at 3.1 v with a 5v Vcc. It has caused me problems.

Chuck.

Thanks for the input. I will check this out.

Added a 10uF cap and 0.1 uF cap and the 10K pullup resistor to the reset line. This had no effect. There seems to be no change on the SPI bus which is what the controller uses to communicate with the LCD board. This code works fine on the arduino mega board. The reset line was at 4.8 volts before i added the pullup. Still no activity that I can see.

I tried a blink sketch and this works fine on the chip but I can’t use SPI communication. I can only use it to upload the code for some reason.

Does anyone have any further information on why this is not working? I am thoroughly stumped.

codedsteele: Does anyone have any further information on why this is not working? I am thoroughly stumped.

Can you get any action out of the 2560? do you have an led you could flash?

Chuck.