General > General Technical Chat
Software guys, please, no.
Howardlong:
--- Quote from: thinkfat on September 19, 2022, 06:00:53 pm ---It's really hard to be an expert in all corners of such a broad playing field.
--- End quote ---
Indeed. Nowadays it's a mental impossibility to "know everything", and it's been like that for about three decades. Before then one could be equally at home designing & building computers, as writing the software that ran on them.
I'm a bare metal RF mixed signal guy, I design and manufacture those designs commercially, but I also have an active career in Fintech, in particular enterprise trading systems focussing on RDBMSs and the associated infrastructure. I've done both for decades. I'm also always learning.
I am, however, although I do partake in woodworking & metalwork, I'm a relative novice with no training, formal or otherwise, so I wouldn't consider pumping out a How-To video on it.
The way I put it was that hardware guys should be careful about recommending going against the grain such as, for example, the use of hard coded literals throughout their code "because it works for them", in the same way software guys should refrain from assuming that they know better when it comes to recommending no resistors.
Look at it this another way, when you're a noob at anything, a key to making progress is to remove as many uncertainties as possible. Let's say that the blinky doesn't work. It could be for many reasons, including, but not limited to, either the GPIO or the LED going bust. However, as a noob you don't know what the risk is. It might be low, but you don't know. So why introduce that uncertainty unnecessarily to begin with?
xrunner:
--- Quote from: eti on September 20, 2022, 03:34:52 pm ---A fact that seems to have escaped people here, due to being hyper-obsessed over his electronics theory... he's not claiming that this is an electronics tutorial - the LED is merely a means to and end, where that end is observing pin state.
--- End quote ---
LOL - no it hasn't "escaped people here", at least not me :-// -
https://www.eevblog.com/forum/chat/software-guys-please-no/msg4422553/#msg4422553
pcprogrammer:
--- Quote from: fourfathom on September 20, 2022, 03:44:49 pm ---That LED looks suspiciously like some I got via Amazon, an assortment of various colors, all with a series resistor buried under the heat-shrink.
Regardless, I can't believe (well, actually I can) that this conversation has gone on for so long. It's just about a software guy not using a series resistor!!! Or is it?
--- End quote ---
For me it is :)
But he uses two LED's. One that is placed in the breadboard. No extended wires, and it looks like just a standard green LED.
And the statement "No resistor for 3.3V" is challenging. Take a 3.3V power supply and hook the same LED on to it. My money is on bye bye LED. With a forward voltage of around 2V the current will go up and up.
eti:
--- Quote from: fourfathom on September 20, 2022, 03:44:49 pm ---
--- Quote from: pcprogrammer on September 20, 2022, 07:29:57 am ---
--- End quote ---
That LED looks suspiciously like some I got via Amazon, an assortment of various colors, all with a series resistor buried under the heat-shrink.
Regardless, I can't believe (well, actually I can) that this conversation has gone on for so long. It's just about a software guy not using a series resistor!!! Or is it?
--- End quote ---
Insecure engineers just like to be outraged at something ALL the time; that's what I pick up on A LOT on EEVblog forums. Perish the thought that someone be as clever as them, or even, <GASP> maybe MORE knowledgeable and experienced than them in their own field (and since no one here can prove to the contrary re Dave Plummer, it's best to show humility and end this idiotic thread)
tooki:
--- Quote from: pcprogrammer on September 20, 2022, 03:53:11 pm ---
--- Quote from: fourfathom on September 20, 2022, 03:44:49 pm ---That LED looks suspiciously like some I got via Amazon, an assortment of various colors, all with a series resistor buried under the heat-shrink.
Regardless, I can't believe (well, actually I can) that this conversation has gone on for so long. It's just about a software guy not using a series resistor!!! Or is it?
--- End quote ---
For me it is :)
But he uses two LED's. One that is placed in the breadboard. No wires, and it looks like just a standard green LED.
And the statement "No resistor for 3.3V" is challenging. Take a 3.3V power supply and hook the same LED on to it. My money is on bye bye LED. With a forward voltage of around 2V the current will go up and up.
--- End quote ---
That's clearly a modern emerald green (~520nm) LED, and those have significantly higher forward voltages (3-3.5V) than traditional lime green LEDs. So when connected to a 3.3V power source, many of them are right in their happy place, even without a current limiting resistor.
If we were talking about old-fashioned 1.7-2.2V LEDs, then it'd clearly be problematic. But with modern 3V+ green/blue/white LEDs, it's actually not preposterous.
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