PDA

View Full Version : problem in avr isp



ashish_agarwal123456
11-24-2008, 03:34 PM
i connected the l293d with atmega8 such that the enable pin of l293d is connected with PB5/SCK pin of atmega8 through 20ohm resistor. now when i try to program it, it is showing error. i have checked the problem is in this connection only. i tried it without 20ohm, with 220ohm, with 1k, with pull down resistor but its still showing error. any suggestion other than using a toggle switch???

i have no other i/o pin left. one more querry... if i program the reset pin as i.o pin using fuse settings then will i be able to program it again using isp?? i mean will reset function work during programming??

ankitmutha
11-25-2008, 09:46 PM
I would like to know how ur trying to program it...
BTW normally u can deal with this situation if u keep the reset switch on.. i mean put GND on reset while programming it.. Resting the mcu protects its ISP pins to be busy in any other work.

ashish_agarwal123456
11-25-2008, 10:17 PM
i am using serial port isp programmer. shorting ground and reset wont solve my problem because it also need a toggle switch. actually i have already find an alternative by using a switch. i asked this question just to find some other solutions. i mean avr support isp. now there can be some discretes attached to those 4 pins used in programming such that they hampers the signal during programming. is there any other solution other than thinking before designing the pcb.