Fixes for cheap AVR programmers

[trigger]

Since Admin had a hard time with his bit-banger (aka, cheap dongle programmer), I dug around and found this very informative post on the topic:

http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=36591

It appears that the problem with most bit-bangers is oscillations in the SCK line, and adding a low-pass filter on this SCK line reduces those pesky oscillations.  I'm just getting started with AVRs, so I don't have a programmer to try it out yet, but I'd be interested to hear if this solves the problem.

[knightimer]

hi, um no1 posted here for a while, i was wondering if people can actually post their results about this link if it really works to stop the lagging-ness of the programming?! thanks!

[ed1380]

just get teh $30 programmer. much better decision.
I learned teh hard way

[HDL_CinC_Dragon]

Yes knightimer, you can post your success(or failure or other thoughts) in this thread if you like about the topic.

[chyoo]

YO MAN HOW IS TI GOING! I NEED TO KNOW IF YOU COULD HELP ME OUT WITH THIS THING HERE, I HAVE BUILD THE CIRCUIT OK I REALY DONT KNOW IF THE LED SHOULD LIGHT AFTER YOU POWER IT OR AFTER YOU PROG IT I HAVE GOTTEN THIS FAR AND NEED SOME HELP TO COMPLEAT IT
THANS MAN

[ed1380]

no double posting

led will blink after you program it and turn it on

[HDL_CinC_Dragon]

no double posting

led will blink after you program it and turn it on

Mine doesnt


Yeah I dont know why but mine doesnt light up. I checked the LED and the resistor but got nothing but good results. I think there just isnt enough mA sinking though the MCU to power my LED or something... its a low watt LED too (1/4 watt I think?) Ill have to fiddle around with it some more.... I need more perf boards... and maybe a big bread board.... I have some internet shopping to do



Oh, and yes, everything else is working as it should on the robot.

[dunk]

YO MAN HOW IS TI GOING! I NEED TO KNOW IF YOU COULD HELP ME OUT WITH THIS THING HERE, I HAVE BUILD THE CIRCUIT OK I REALY DONT KNOW IF THE LED SHOULD LIGHT AFTER YOU POWER IT OR AFTER YOU PROG IT I HAVE GOTTEN THIS FAR AND NEED SOME HELP TO COMPLEAT IT
THANS MAN

it's been asked before on the forum if you search.
the LED does not light untill after you program the AVR.

Yeah I dont know why but mine doesnt light up.

you got the polarity of the LED round the right way?
what voltage do you measure across the LED with a multimeter?

dunk.

[cooldog]

did you accidentally buy a in-fared LED

[HDL_CinC_Dragon]

did you accidentally buy a in-fared LED

Id be pissed lol but no

you got the polarity of the LED round the right way?
what voltage do you measure across the LED with a multimeter?

Im pretty sure ive got the polarities right. The Positive terminal should be the one that runs to the resistor then to the MCU right? Since the current is supposed to be sinking to the MCU?
Im not too sure what voltage I used to test it but im assuming it was very very low voltage. I used my DMM on one of its resistance settings and touched the corresponding poles on the LED and it lit up red a little bit. Ill quadruple check again just to make sure.

[paulstreats]

its the other way around, the resistor should be connected to the cathode of the led, and then to the mcu by the looks of it.

An easy way to test, and also way for people to test the circuit for shorts who dont have a multimeter is to remove the mcu, attach the batteries then touch a spare piece of wire between an gnd terminal and the mcu pin that the resistor goes to. If the led lights up, then there arent any shorts on the basic power circuits.

[Ro-Bot-X]

Has any one of you worked with this programmer? Is it reliable, or not worth building?

[HDL_CinC_Dragon]

I did your idea with a half dead 9v

I put the positive wire in DIP pin 6 and then the negative wire in DIP pin 8(GND)... then I accidentally put it in pin 7(VCC) and it lit up with that too O_O... same for pins 21(AREF) and 22(GND)... im assuming thats a bad thing... Do I have a short? or is there another component on the board linking them? the vreg perhaps?... oh wait, i think its the ceramic capacitor... it also lights up whenever I touch it to a data pin that has a sensor or servo hooked up to it... hmm. peculiar....


Oh crap, I have to lave for work like right now lo

[pomprocker]

since I like to dig up old posts.....


I found that when using the cheap bit-banger programmer on an old laptop with a serial port directly connected to the programming pins on the $50 robot mcu that it programs and verifies instantly.

When I try to program on my newer laptop using an usb to serial converter with long serial cables then it takes hours!!

[HDL_CinC_Dragon]

When I try to program on my newer laptop using an usb to serial converter with long serial cables then it takes hours!!

apparently its the USB to Serial that causes this problem. Personally I havnt used that method and dont ever plan to