Help on 1284p bootloader :(

Hi every one :slight_smile:
plz i need help to connect my ATmega1284p with FT232R
i make a board, and i cant connect it to the PC :frowning:
it was my job, i got this old board, and my job was make a new one,
so i got an old schematic and redesign it, like the original board, new processor mega1284p with the same pins like the original …
but i cant not connect it to the pc
i have connection to the board, com4 , but i cant install any program , i tried Arduino - Atmel Studio 7.0 - BASCOM-AVR ( like the original code on the old board was written by BASCOM) … but no connection , the pc can not define the micrcontroller so i cant not send code to it !
what is missing ? and this con7 on the schematic , i have no idea why is it here .
i am an electrical , i have not much info about microcontrollers .
the man who made it back on 2007 is dead, and i got this work to redesign it, but i need help .
thanks alot

Reset circuit is missing. It should be DTR from FT232RL. See original Arduino UNO R3 schematics.

but i cant not connect it to the pc

But you can see its COM port, can you? So, it is connected.

And if its a ‘new processor mega1284p’ you will need to burn the bootloader to load programs from the FT232.

And its often not helpful to only show part of a schemtic, there could be other parts of the circuit causing problems.

Budvar10:
Reset circuit is missing. It should be DTR from FT232RL. See original Arduino UNO R3 schematics.

But you can see its COM port, can you? So, it is connected.

ok i will take a look ... thanks

yes after installing FT232R-USB_Driver i got a connection on com4, but i dont know if that is enough to say the chip is right connected, i dont know this man how he did it like this ...

i will try, thanks

srnet:
And if its a 'new processor mega1284p' you will need to burn the bootloader to load programs from the FT232.

And its often not helpful to only show part of a schemtic, there could be other parts of the circuit causing problems.

yes, i made a new board, but the old chip atmegaXX i forget what it was, i could not find it, it is too old, i got a replacement with same pins mega1284p .
i thought it is just connect & run.
any way, thanks , i will try to do more research

FT232 is ATmega’s interconnect to PC.
ATmega needs:

  1. power
  2. clock/crystal
  3. reset circuit - missing
  4. a bootloader uploaded via ISP - ? (pointed by @srnet).

Budvar10:
FT232 is ATmega's interconnect to PC.
ATmega needs:

  1. power
  2. clock/crystal
  3. reset circuit - missing
  4. a bootloader uploaded via ISP - ? (pointed by @srnet).

1 - it is ok, runnig 5V
2- i have 16000Hz
3 - i fixed now, DTR to Rest with R 10k and 100nF this like this scheamtic


4- hmmm, so i have to look for a way to uploaded a bootloader on it ... still to be done

FT232R?
Maybe COM4 is for something else?
You’ll need to check which uart IC you’re using and install drivers for it.

Ok
i made like this
https://www.instructables.com/id/How-to-use-Arduino-Mega-2560-as-Arduino-isp/
because i have an Arduino-Mega-2560
i made the connection direct to my atmega1284p to the right contacts
mosi - miso - sick - rest
+ 5v power + 16000Hz crystal
but i keep gotting this error
Device signature = 0xffff00
Expected signature for ATmega1284P is 1E 97 05
what is missing here ? wrong connection some where ? i cheeked 100 times i correct it
before that i got other error , now this one
Device signature = 0xffff00
Expected signature for ATmega1284P is 1E 97 05
i dont know what is missing in my connection or i have to modfi the programmer Arduion as ISP
**thanks **

Some FF in response could be caused by shortage on wires.
Anyhow, post whole log include command at the top and check pins on 2560 according the sketch you've used.