Recent content by Alan Sailer

That is an interesting scenario. And it makes sense. It's very unlikely in this situation though. The chips that died where in circuit, powered-up, connected to the laptop and working. I was programming them over several cycles and then I was unable to program them. This happened three times...

I would like to know what killed them also but short of trying to kill more is isn't going to happen. Since the chips still draw the rated current they are not dead from over-current. All the supplies are quality bench top style units that I have use for many projects. Cheers.

Thanks for all the replies. This forum has been very helpful. This silly project has endured many false starts and roadblocks. Some are my fault. The bottom line is that it is such a stupid project in the first place. I just want to hear frogs croaking when my timer is done. Through no ones...

No. They all test bad according to the serin/serout test and none respond to attempts to program them.

Hello, I am tapping into group wisdom to solve a problem. I am using an old 18A chip to make a timer. The output pins are all being used to send two BCD digits to the display. I need to somehow supply a signal when the count reaches zero to set off my MP3 player/speaker. One non-elegent idea...

inglewoodpete, Thanks. You seem to have supplied the acid test. I was looking for a black and white go/no-go. The fact that the chips are drawing the expected current leads me to believe that somehow the firmware was corrupted? Or is it more complicated than that? I did a non-definitive test...

inglewoodpete, So I got the scope out and ran the tests that you describe. With a good chip in the board, the following happens, SerIn Low initially, goes HIGH when the download button is pressed. SerOut Low initially then a series of pulses as the programming bar progresses. With...

inglewoodpete, I kind of figured 4Hz was a typo. I have been performing hard re-sets. I cannot think of a harder reset than physically shorting the power supply and then opening it after the download process has started. I am tired of doing this. I am officially insane at this point, by one...

kfjl, Sorry that I ignored your earlier post since it didn't make sense to me. The new post does. However, the board I made years ago (and that I am using now) has a 4.7kohm pull-up resistor attached to pin 4. The reset button grounds pin 4. Just like the manual specifies. Cheers.

So here is the code, warts and all. I was actively working on modifying the code to make a high/low/high pulse that will turn on a MP3 player to make my frog noises. I apologize if the formatting is screwy or any other coding faux-pas have been committed. The basic code was lifted from a...

erco, The board is etched at home. It is a single sided board and soldered on the back side. I have used this batch of PCBs on at least ten projects with no problem. The last one was about two months ago. Using the "new" USB programming cable. Shorts? Nothing is impossible. However the chip is...

premelec, I will look into that. I'm sure it's simple to do but so am I. I have done a hard reset several times. Since my supply is current limited it is no problem to physically short out the supply. I used a set of tweezers. The PC board that hold my chip has a small electrolytic bypass...

erco, I will look into that. I very seldom post pictures and have never posted software on forums and will have to figure out how to do this. Cheers.

Thanks all for the ideas of things to try. I will need a bit of time to try them out. Cheers.

erco, If a smoking gun means that I used the cable for two weeks without any problem...then suddenly it went crazy and sometimes kills chips and other times does not. Nothing is impossible but that seems unlikely. premlac, A battery will supply much more current than any supply that I am...