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I currently have Attiny85 , attiny45 , atmega328 , 8051 MCU . I want to program them in a chipless method ( which doesn't use any intermediate chips to burn program or bootloader ) - this is like a chicken egg problem

I have a VGA connector cable ( 3 row db15 ) , i have pcb perfboard , breadboard, and passive components (capacitors , transistors resistors ) , 12 volt battery , wires etc .

On my MACBOOK AIR i have attached a usb c type to usb 3.0 converter .

questions -

1.how can i build a serial avr programmer to program my MCU chips using ISP method from my MACBOOK.

  1. I have searched about Serial and parallel avr programming and most said that because of voltage levels , direct serial programming wont work for an avr , but is it possible to use serial network for data transfer while powering the setup up with an external voltage source , would that work the same as direct serial cable programming of AVR chips?
  1. i have a VGA cable , how do i configure it to use it like DB9 cable , is that a thing we can do ?
  1. Lastly any extra help provided with an updated Universal AVR serial programmer circuit schematic , which works with usb to serial converter cables or in general with non serial port laptops , would be great .
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  • \$\begingroup\$ Anything you could make yourself would be more difficult and more expensive than just buying a dedicated programmer. Pololu sells one for less than $8. \$\endgroup\$
    – Hearth
    May 18 at 4:00
  • \$\begingroup\$ arduino.cc/en/Hacking/ParallelProgrammer \$\endgroup\$
    – Juraj
    May 18 at 5:08
  • \$\begingroup\$ question 3 ... cut off the VGA connectors ... solder on DB9 connectors \$\endgroup\$
    – jsotola
    May 18 at 6:19
  • \$\begingroup\$ Ok I see, but why would you do that ? Is is for the challenge of it ? To avoid waiting for the delivery of the programmer you forgot to buy ? ;-) Or to spare a few $ ? \$\endgroup\$
    – Blup1980
    May 18 at 7:00
  • \$\begingroup\$ @Blup1980 i actually want to make this because i want to program my MCU fresh , and then make a USBASP programmer myself , only way i could find a way was bitbanging the MCU , which requires serial programming of MCUs , hence asking for help on that , and how i can do it if i dont have a dedicated rs232 port in my computer \$\endgroup\$ May 20 at 2:48
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I currently have Attiny85 , attiny45 , atmega328 , 8051 MCU. I want to program them in a chipless method ( which doesn't use any intermediate chips...

Sorry, that isn't possible. You need a USB interface, and this will need at least one chip.

I have searched about Serial and parallel avr programming and most said that because of voltage levels , direct serial programming wont work for an avr , but is it possible to use serial network for data transfer while powering the setup up with an external voltage source

It's not just voltage levels, the serial protocols of USB and ICSP are fundamentally incompatible. The USB port in your computer will only 'talk' to a device which has a USB interface, and you cannot build one using only a VGA connector cable, a few capacitors transistors and resistors, and a 12 volt battery.

You may have heard of programmers which connect to a computer's RS232 serial or parallel printer port that only need a few passive components. In the days when computers had such ports this was possible because they could be 'bit-banged' to directly control individual pins on the port, but this is not possible with USB.

i have a VGA cable , how do i configure it to use it like DB9 cable , is that a thing we can do ?

No, it's not a thing you can do.

Lastly any extra help provided with an updated Universal AVR serial programmer circuit schematic , which works with usb to serial converter cables or in general with non serial port laptops

There are circuits that purport to work with RS232 serial ports that may or may not work with a USB to serial converter. They are a disgusting hack and I don't recommend using any of them.

The obvious solution is to obtain a USB programming adapter compatible with your MCUs, eg. USBasp. These are available just about everywhere and only cost few dollars.

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  • \$\begingroup\$ sir then how do the chips used for usbasp are burnt with the bootloader ? I actually want to bitbang and not use any intermediate chip , you mentioned about serial programming using rs232 system , is that in any way replicable or could be simulated for programming avr mcus ? \$\endgroup\$ May 20 at 2:30
  • \$\begingroup\$ "sir then how do the chips used for usbasp are burnt with the bootloader ?" - a good question. Commercial devices are usually 'burnt' with a standalone production programmer. Microchip can supply AVR MCUs with your program 'burnt' into them for a fee. \$\endgroup\$ May 20 at 5:15
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    \$\begingroup\$ "you mentioned about serial programming using rs232 system , is that in any way replicable" - circuits like this may work with some USB to serial converters, or you could use a USB to GPIO adapter like the FT232H. But getting them them to work could be a frustrating exercise. USBasp's sell on eBay for ~US$3 and work 'out of the box', so why bother trying to make one yourself? \$\endgroup\$ May 20 at 5:27

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