jkwilborn

Where's the QRP rig stuff? 73s :)

I saw no indication that you could hook these up in parallel in the data sheet, if so, please point that out to me. Most things like this you can't parallel because the small differences in voltage when they switch is a problem. When you do attempt this, at minimum you need some kind of resistance to allow the load to balance. That is usually what you don't want to do as you want it to switch with the lowest on resistance. So adding resistance is futile ^-^ ...IgorS32 pointed this out to everybody in his note about the bad practice of tying different power supply outputs together. Same game...It indicated (to me, the datasheet) that you can pull 4 amps through one side or the other (only one motor port can be used.) Or something like 3.25 amps on one motor and 750 milliamps on the othe…

I saw no indication that you could hook these up in parallel in the data sheet, if so, please point that out to me. Most things like this you can't parallel because the small differences in voltage when they switch is a problem. When you do attempt this, at minimum you need some kind of resistance to allow the load to balance. That is usually what you don't want to do as you want it to switch with the lowest on resistance. So adding resistance is futile ^-^ ...IgorS32 pointed this out to everybody in his note about the bad practice of tying different power supply outputs together. Same game...It indicated (to me, the datasheet) that you can pull 4 amps through one side or the other (only one motor port can be used.) Or something like 3.25 amps on one motor and 750 milliamps on the other, adding up to 4 amps total. This makes sense since the heat dissipation (heat sink) is probably connected to both controllers and if one is unused it will change the others thermal characteristics, as far as how much heat (amps) it can tolerate.Half (or more) of these questions would not be asked if they would use the thing their hands are on. I googled "l298n current limit", scrolled down and found the following entry"Motor driver: L298N. Motor channels: 2. Maximum operating voltage: 46 V. Peak output current per channel: 2 A. Minimum logic voltage: 4.5 V. Maximum logic ..." Took me less than 30 seconds... This is not demeaning but it is stress the education of the possibilities of these search engines and their incredible caches of data. It is only to help them learn what a great tool it is and how under. used. it is.Probably found their way here with a search engine anyway. Putting the load on people like Reichenstein7, who did such a great article!... ;p}If you require 50% more than the devices' limit (not only in amps, but anything else), forget that part and move on. By this description it's 300% more power than possible with this device.IMHO :-OThe dumbest person can ask the smartest man questions he cannot answer.P.S. Sorry it was so long...

Check the Wiki here:https://en.wikipedia.org/wiki/Transistor_countJust curious so I took a couple of minutes. One engineer estimated the AVR 8 bit processors have around 10,000 transistors. Never found a statement from Atmel.One of the micro processor engineers stated something like "we don't start with 500,000 transistors and then figure out how to wire them together."I know it's been a while for this thread, but this Wiki's a good reference.Good luck... :-)

When I'm talking about PIND = _BV(PD7) code, the PIND is usually used to read the port, but if the pin is an OUTPUT pin it will flip it on a write. Typo... thanks

N8DAH de KA7CMF bkMost of the boards today are very complex and are multi layered. I worked for a manufacturer here and they spent over a 1/2 million for a machine to do the remove and install on our boards which had 6 layers. All of us were very good at soldering, but none of us could change out a chip without damage. This was twenty + years ago, now it's norm in mainstream electronics. I'm sure many of the problems on this are directly related to too much heat or mechanical energy, incorrectly applied. Think of a iPhone, do you think you could solder and unsolder stuff on it. It's the normal today. The best tip, if you can, is to use a solder wick, put electrical flux on it (the wick) and heat as little as possible as quick as possible. Don't use short touches with the iron, as yo…

N8DAH de KA7CMF bkMost of the boards today are very complex and are multi layered. I worked for a manufacturer here and they spent over a 1/2 million for a machine to do the remove and install on our boards which had 6 layers. All of us were very good at soldering, but none of us could change out a chip without damage. This was twenty + years ago, now it's norm in mainstream electronics. I'm sure many of the problems on this are directly related to too much heat or mechanical energy, incorrectly applied. Think of a iPhone, do you think you could solder and unsolder stuff on it. It's the normal today. The best tip, if you can, is to use a solder wick, put electrical flux on it (the wick) and heat as little as possible as quick as possible. Don't use short touches with the iron, as you will overheat it. These surface mounts make it even worse, as you used to be able to clip a heat sink or something on the legs. You touch anything today, it might not survive even the slightest modification. You pay your money and take your chances....73'sJack

Thanks so much. I have just gotten a pair of UNO's and a display. Just curious as I've not found mention of the sd card on the display. Is it like the others I've seen where you can only use if for program data storage or something...Thanks Very much.....JackArizona