Atmega1284p wont reset for programming with FTDI module

Hi,

Ive been using the mighty core with atmega1284p chips for sometime now.
Lately it seems I am unable to reset the chip for programming though an FTDI USB to TTL module.
The DTR line of the module is connected to the reset pin of the CPU though a 100nF capacitor as always but the CPU simply wont reset and I have to manually press the reset button during sketch upload.

Any ideas why?

Is the DTR line going low? Is it high prior to attempting the upload?

If the answer to both is yes, assuming the laws of physics remained constant, there is a bad connection somewhere in your autoreset circuit...

DrAzzy:
Is the DTR line going low? Is it high prior to attempting the upload?

If the answer to both is yes, assuming the laws of physics remained constant, there is a bad connection somewhere in your autoreset circuit...

Yes and Yes! I have a 10k pull up resistor. Same circuit worked flowerlessly before.

I dont know about the "laws of Physics" but I can detect the reset signal going low on the reset pin of the MCU.

If the pin is going low but the processor is ignoring it, sounds like a fuse error where the pin has been set to be I/O rather than a reset. Not familiar enough with the 1284 to know for sure if that is possible and I’m too lazy to dig into the datasheet ATM.

Watcher:
Yes and Yes! I have a 10k pull up resistor. Same circuit worked flowerlessly before.

I dont know about the "laws of Physics" but I can detect the reset signal going low on the reset pin of the MCU.

The pin needs to go low and go back high again; does that indeed happen?

sterretje:
The pin needs to go low and go back high again; does that indeed happen?

Yes it does.

Used a scope to check it.

BTW, I am using an arduino as a programmer to program the chip as I ve always done.