Search found 1597 matches

by ahull
Tue Oct 17, 2017 10:28 pm
Forum: General discussion
Topic: Power Blue Pill and Maple Mini from external 3.3 source?
Replies: 5
Views: 153

Re: Power Blue Pill and Maple Mini from external 3.3 source?

If the datasheet mentions reverse protection, or shows some sort of schematic of the output stage, you might get some clues. I suspect, given how the output stages tend to work, it would care if you feed it 3.3V, but I'm no expert, so I'll throw that one open to anybody else that wants to chime in. ...
by ahull
Fri Oct 13, 2017 10:03 pm
Forum: General discussion
Topic: Power Blue Pill and Maple Mini from external 3.3 source?
Replies: 5
Views: 153

Re: Power Blue Pill and Maple Mini from external 3.3 source?

It probably is bad practice, but I have done this in the past. As to damaging the LDO, that would depend on which LDO is fitted, and whether the manufacturer allows for this mode of operation. Check the datasheet.
by ahull
Fri Oct 13, 2017 9:56 pm
Forum: General discussion
Topic: Power LED questions
Replies: 10
Views: 230

Re: Power LED questions

How about my thought about just taking flush cutters and cutting the LED in half? That shouldn't lead to any problems? (I've done it in the past with a Digispark LED, but some time later the Digispark blew. Presumably unrelated.) This would put a large mechanical load on the printed circuit traces,...
by ahull
Thu Oct 12, 2017 12:27 pm
Forum: General discussion
Topic: Power LED questions
Replies: 10
Views: 230

Re: Power LED questions

To put that in perspective, if the LED lights at 0.1mA, it will eat a CR2032 (nominal capacity of around 200mAh) in around 80 days. For every doubling of that LED current, you half the duration the battery will last. If you remove the LED, obviously your battery will last a lot longer. That same CR2...
by ahull
Thu Oct 12, 2017 7:48 am
Forum: General discussion
Topic: Power LED questions
Replies: 10
Views: 230

Re: Power LED questions

Andy I agree about removing the resistor, it would be my first option, as they remove very easily. I wasnt aware that the regulator drew current though its output, but I'm not surprised that it does, since its not its normal mode of operation. It very much depends on the regulator, but generally th...
by ahull
Wed Oct 11, 2017 9:11 pm
Forum: General discussion
Topic: Power LED questions
Replies: 10
Views: 230

Re: Power LED questions

Removing the power LED on the bluepill boards is relatively easy. You might also consider removing the current limiting resistor instead, if it is easier to access, or if you are feeling particularly brave, substituting it for a higher value, though this will require considerably more skill than sim...
by ahull
Wed Oct 11, 2017 8:52 pm
Forum: New users MUST post here first, and let us know a bit about you and your projects
Topic: Greetings from Seattle
Replies: 3
Views: 83

Re: Greetings from Seattle

If it is using anything other than the modes provided by STM, then it is probably bit banging the serial port rather than using the defined hardware options.... at least if I were set the challenge, that would be the method I would pursue. :D Having said that, the Arduino serial.begin() function pot...
by ahull
Tue Oct 10, 2017 12:12 am
Forum: Projects
Topic: F405 & F411 versions of the BluePill
Replies: 223
Views: 2574

Re: F405 & F411 versions of the BluePill

If the objective is to save space, with the BOOT jumpers, then don't forget that pin headers and jumpers also come in 1.0mm pitch (mostly smd) as well as the more common 2.54mm (mainly through hole, but occasionally smd). They will be slightly more expensive, and more difficult to source. They are p...
by ahull
Mon Oct 09, 2017 11:57 pm
Forum: New users MUST post here first, and let us know a bit about you and your projects
Topic: Hi from Bandar-e Anzali
Replies: 2
Views: 90

Re: Hi from Bandar-e Anzali

Hi Ahmad. The only thing I vaguely know about bandar-e Anzali is that it is famous for its caviar, but since the nearest I've been to bandar-e Anzali is flying past it over the Caspian sea at 37,000 feet, en route to India, I could be entirely wrong about that.
Either way, welcome :D