Timeline for Light a led without GPIO board
Current License: CC BY-SA 3.0
17 events
| when toggle format | what | by | license | comment | |
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| S Aug 4, 2016 at 16:53 | history | suggested | Oliver | CC BY-SA 3.0 |
fixed some grammar issues
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| Aug 4, 2016 at 14:54 | review | Suggested edits | |||
| S Aug 4, 2016 at 16:53 | |||||
| Aug 4, 2016 at 11:39 | comment | added | HallMark | Yes, At last I suggest to go with 1K. | |
| Aug 4, 2016 at 11:16 | comment | added | goldilocks♦ | ...It could even be as little as half that with some LEDs but 120 is a safe starting point. You are also probably okay going with 20 mA current but do beware not to exceed ~80-90 mA total from all the GPIOs if you are connecting multiple LEDs to different pins. ledcalc.com | |
| Aug 4, 2016 at 11:15 | comment | added | goldilocks♦ | Actually the resistor in an LED circuit isn't there so much to protect the Pi as it is to protect the LED, which will probably burn out before anything else (although I can't promise that isn't risky for the pi either). Anyway, 330+ ohm's is probably massive overkill. You can find "led resistor calculators" online to confirm this, but the formula is a version of Ohm's law: resistance = voltage / current. The "voltage" in this case includes the forward drop of the LED, which might be -1.5 to -3 V; if we then assume 15 mA of current, that's (3.3 - 1.5) = 1.8 / 0.015 = 120 ohms. | |
| Aug 4, 2016 at 5:17 | comment | added | HallMark | Let us continue this discussion in chat. | |
| Aug 4, 2016 at 5:13 | comment | added | HallMark | Yes, We have to limit the current passing thru circuit to avoid damage to LED/Pins. You can use any resistor in between 330 ohm to 1 kohm. Let me know if you have any other doubt about hardware connection. | |
| Aug 4, 2016 at 5:11 | vote | accept | Ionică Bizău | ||
| Aug 4, 2016 at 5:11 | comment | added | Ionică Bizău | * Therefore putting the resistors in the circuit will ensure that only this small current will flow and the Pi will not be damaged.* – Actually looks like that's required. Thank you very much! | |
| Aug 4, 2016 at 5:10 | comment | added | Ionică Bizău | Yes, I think I have some wires around. :) Do I really need a resistor too? What is it for? | |
| Aug 4, 2016 at 5:02 | comment | added | HallMark | I have updated answer with LED Connection image you can connect something like that. | |
| Aug 4, 2016 at 5:01 | history | edited | HallMark | CC BY-SA 3.0 |
LED Connection image added
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| Aug 4, 2016 at 4:57 | comment | added | HallMark | That board helps you to avoid any false short circuit when connecting and if you really not want to use that one then get wires and connect same connection manually without board. | |
| Aug 4, 2016 at 4:49 | comment | added | Ionică Bizău | I have a Raspberry PI 2 B+. I don't have that kind of board with many holes in it, but I would like to use the pins from Raspberry Pi directly. Isn't that possible? How can I connect the LED to them? | |
| Aug 4, 2016 at 4:42 | comment | added | HallMark | Which Raspberry Pi model you have? Without connecting LED how can you turn ON LED? | |
| Aug 4, 2016 at 4:19 | comment | added | Ionică Bizău | The problem is that I don't have a breadboard. Let's assume I only have the Raspberry Pi accessible via wifi and an LED. Is it possible to turn on/off the LED this way? | |
| Aug 4, 2016 at 3:56 | history | answered | HallMark | CC BY-SA 3.0 |