Pages: 1 [2]   Go Down
Author Topic: So what's up with those folks trying to use LCDs and just don't want to use pot?  (Read 1714 times)
0 Members and 1 Guest are viewing this topic.
IRL
Offline Offline
Full Member
***
Karma: 0
Posts: 146
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

What is worst are the morons that think resistors on LEDs are unnecessary.

Resistors aren't really much used for power LEDs.
If a component is neccessary isn't defined by what someone thinks, but by the circuit, and the component specifications.
Logged

I also have PIC related web domain.

ਪੰਜਾਬ
Offline Offline
Edison Member
*
Karma: 12
Posts: 1601
Another year! Alone! :(
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

@ liudr , i was thinking another addition, I think there must be or can be a Beginner's list of getting them started in each case that the starting people take up like:

> getting started with motor's?--> Yes--> OK then get these ingredients! in your lab
> getting started with LED's/DC lighting --> Yes--> OK then get all this stuff
> getting started with External Programmer--> Yes --> OK start learning this way.
> getting started with Wireless(Bluetooth)--> Yes--> OK get these ingredients.
> getting started with Wireless(RF)--> Yes --> OK get these ingredients.

in addition to "get these ingredients" we can also add-up some guidelines and anyother additional stuff that we think might provide an Helping hand and lower the forum cluttering with redundancy.

also, i think these days some experts are fed up of answering the very often/very monotonous/very repetitive same questions of the ever entering newbies into forum and their(newbies) not clarifying with the basics which are already available if a bit search is done saving their and other people's time.
Logged

"Real Men can Accomplish  Anything"
-  Website  
- skype : nishants5  

ਫ਼ਤੇਹ ਕਰੂਂ !

Central MN, USA
Offline Offline
Tesla Member
***
Karma: 73
Posts: 7197
Phi_prompt, phi_interfaces, phi-2 shields, phi-panels
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

What is worst are the morons that think resistors on LEDs are unnecessary.

Resistors aren't really much used for power LEDs.
If a component is neccessary isn't defined by what someone thinks, but by the circuit, and the component specifications.

If arduino has constant current supply it would not need a resistor either but it has a constant (to certain limit) voltage supply instead. You are totally mixing up these two situations. The arduino is the constant voltage situation and a resistor is always needed.

Good idea NI$HANT, the more specific hardware will depend on local suppliers too so I wish there were lists for parts suggestions say USA/UK/Australia/India/... where lots are playing with Arduino.
Logged


CO, USA
Offline Offline
God Member
*****
Karma: 5
Posts: 711
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Saying "RTFM" seems like hitting zombies with a bat.

I believe that zombies are vulnerable to blunt impact trauma, provided it is directed at the cranium, and delivered with sufficient force. smiley

I might be mistaken, but I get the impression that there a lot of people who buy just an Arduino, and not one of the starter kits. And it seems that this occurs before doing much reading on the various forums and vendors' websites. That seems the biggest challenge -- to get people to do some reading first, before buying just an Arduino and then asking, "How do I do X?". Alas, liudr, this is the way of things in many areas, not just Arduino, and if you spend enough time on any topic-specific boards, you'll see that this pattern repeats ad nausem whether the topic is Arduino, the AR-15, electronic cigarettes, or any other thing that has a forum associated with it. One thing I notice is that other forums almost always have a 'Getting Started' or 'newbie' sub-forum, with stickied topics covering the essentials. We don't have that here. Anytime I hit a new forum, that's always what I look for.

I wonder how many newbies read the Getting Started pages before posting. Might be interesting to see some site statistics on what pages here, other than the forum, get the most traffic.
Logged

... it is poor civic hygiene to install technologies that could someday
facilitate a police state. -- Bruce Schneier

ਪੰਜਾਬ
Offline Offline
Edison Member
*
Karma: 12
Posts: 1601
Another year! Alone! :(
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I believe that zombies are vulnerable to blunt impact trauma, provided it is directed at the cranium, and delivered with sufficient force.

The information backed by Day of the Dead ,Dawn of the Dead, Land of the Dead, Night of the Dead......Endless other classis American Zombie movies i have watched.

Quote
Good idea NI$HANT, the more specific hardware will depend on local suppliers too so I wish there were lists for parts suggestions say USA/UK/Australia/India/... where lots are playing with Arduino.

 smiley In places like India the main big distributors are not only distributing Arduino but also distributing stuff after importing from SparkFun so in nutshell everything is in reality American ,USA made or made on the same platform of the US developers, Hardly things are unique.
Logged

"Real Men can Accomplish  Anything"
-  Website  
- skype : nishants5  

ਫ਼ਤੇਹ ਕਰੂਂ !

Global Moderator
Offline Offline
Brattain Member
*****
Karma: 485
Posts: 18806
Lua rocks!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

It would be useful to indicate what is the best way though. For example, in Australia we can order direct from the USA, and it arrives reasonably quickly. But sometimes the minimum shipping charge is something like $35. Now we might order from an Australia supplier for more per item but a lower shipping charge.

I think the "worst" suppliers are those that refuse to use the mail, and opt for "courier" shipping. That can make a difference between $10 for a parcel, sent airmail, and $30 to $40. And when you want a $20 device, $40 shipping makes it pretty expensive.
Logged


ਪੰਜਾਬ
Offline Offline
Edison Member
*
Karma: 12
Posts: 1601
Another year! Alone! :(
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
That can make a difference between $10 for a parcel, sent airmail, and $30 to $40. And when you want a $20 device, $40 shipping makes it pretty expensive.

That is true for me, The distributors here can't be expected to have each and every item that sparkFun may make and sell.

However Seeedunio people are good in this case just order above $50 USD and get all stuff that you may want.no shipping there.
Logged

"Real Men can Accomplish  Anything"
-  Website  
- skype : nishants5  

ਫ਼ਤੇਹ ਕਰੂਂ !

IRL
Offline Offline
Full Member
***
Karma: 0
Posts: 146
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

What is worst are the morons that think resistors on LEDs are unnecessary.

Resistors aren't really much used for power LEDs.
If a component is neccessary isn't defined by what someone thinks, but by the circuit, and the component specifications.

If arduino has constant current supply it would not need a resistor either but it has a constant (to certain limit) voltage supply instead. You are totally mixing up these two situations. The arduino is the constant voltage situation and a resistor is always needed.

Good idea NI$HANT, the more specific hardware will depend on local suppliers too so I wish there were lists for parts suggestions say USA/UK/Australia/India/... where lots are playing with Arduino.

I did not write "resistors are not needed", or, "resistors are not needed for connecting LEDs to Arduino". I wrote it's defined by the component specification/circuit.

Actually, I will try now, connect one LED without resistor (to ATMega328), and measure the current. Of course using precaution, at first setting the port bit high, then carefully tapping the LED lead to the PCB.
Logged

I also have PIC related web domain.

Central MN, USA
Offline Offline
Tesla Member
***
Karma: 73
Posts: 7197
Phi_prompt, phi_interfaces, phi-2 shields, phi-panels
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

You are only getting one data point. I think it's safer to have that LED on a variable power supply that displays both voltage and current. We call that I-V characteristic lab smiley
Logged


Pages: 1 [2]   Go Up
Jump to: