50 buck robot question

[Hermes Chen]

yes, another noob asking about the 50 buck robot
well, i am sorry if the question is a little noob, but since I am new to this and  I can't buy the 340ohm and 1.62K ohm resistor, can I replace them with the 330ohm resistor and the 1K ohm resistor?
thanks guys in advance, I really appreciate it.

[photomark]

I am not to familiar with the $50 robot but I am familiar with resistors , 340Ω to 330Ω is only a small difference and should be OK but 1.62kΩ to 1kΩ is a lot and this may cause problems in any circuit , would be better if you could get a 1.5KΩ or 2KΩ or a combination to get the original value   

[Elijah5647]

For that resistor you should go with a bigger resistor so the 2k ohm or something there about whatever you can find.

[VegaObscura]

The 330 ohm resistor should work fine in place of the 340 ohm resistor.  You can combine your 1k resistor and two 330ohm resistors to get 1.66k, which should be close enough to 1.62k.  It doesn't matter what order you put them in, as long as you connect them in series.

[Hermes Chen]

thanks guys, I've already solved the resistor problem by simply buy one (silly, yeh?)
however, I got another problem. Is there an alternative way to connect the atmega8 to the computer (like USB port or COM) since I can't buy the AVR ISP2 Programmer. Actually I can, but I live in Vietnam, where shipment can get really nasty. So anyone out there have a solution, please help me out. Thanks

[VegaObscura]

You can use any one of the three programmers listed.  The AVR ISP2 programmer is generally accepted as the highest quality, but the cheaper STK dongle programmer works fine for me, unless you need to program fuses (you shouldn't have to).  There's also the AVR Pocket Programmer, if that one seems to work for you in terms of price and shipping.

For most beginners, I recommend the STK dongle programmer.

[Hermes Chen]

thanks, anyway. but what I really need to know is, is there a way to connect the microcontroller to the computer using a different port by changing the microcontroller schematic? I heard of a bootloader called avr910, can I use that instead?

[voyager2]

thanks, anyway. but what I really need to know is, is there a way to connect the microcontroller to the computer using a different port by changing the microcontroller schematic? I heard of a bootloader called avr910, can I use that instead?

You need a programmer to transfer a boot loader to the chip.
Then you need an RS 232 or USB to TTL converter for the boot loader to communicate with the PC.

See the bootloader tutorial:
http://www.societyofrobots.com/bootloader_50_robot.shtml

and the UART tutorials (all about communication):
http://www.societyofrobots.com/microcontroller_uart_50_robot.shtml

http://www.societyofrobots.com/microcontroller_uart.shtml

[VegaObscura]

If you're trying not to buy a programmer at all, you can  buy an atmega8 with a bootloader preinstalled for a couple of bucks more.  Just search for it.

[Hermes Chen]

well I have bought the avr910 and I can't seem to load file .hex to the programmer.
the avrdude keep saying "error: selected device is not supported by programmer: m8"