-1

Welcome, i've got a question that is bugging me for quite some time lately. I've got RaspberryPi zeroW with ZeroCam camera module (without IR filter). To get it to work in dark I bought IR LED modules as seen here:

https://www.amazon.com/Infrared-Illuminator-Adjustable-Resistor-Raspberry/dp/B07FM6LL3V

I know they can be powered by screwing them to dedicated camera, and then the will draw current from CSI interface which is also 3.3v. My question is, can i safely power this IR light modules (or at least one of them) from 3.3v GPIO (1 or 17). My power supply is 2.1A.

Thank you in advance for any clue.

edit 24.10.2019

After quite a while of waiting i've received a clue from local reseller. They said that 3W is a power of pair of modules, meaning one of them will be 1.5W

Improve this question
6
  • Ah, let me see. Your IR LED module spec says this: "3W high-power 850 infrared LED,designed to work for Raspberry Pi camera". (1) This module is "independent" of Rpi + camera, in the sense that there need NOT to be any power connection or signal transfer. (2) In other words, you can just use 1.5V x 2 = 3V to supply power to this module. (3) If you use 3V battery bank as (2) above, the current is Power / Voltage = 3W / 3V = 1A. Rpi's 5V (pin 1) or 3V3 (pin 17) power rail can barely supply 1A max, but that might be heat up things and NOT recommended. – tlfong01 Oct 23 '19 at 13:25
  • @tlfong01 Thank you for quick answer. Producer of this module recommends using heat sinks because "it can heat raspberry". But... they are used in pairs and both get power from CSI interface, meaning they would be using 2A via CSI. Would'nt it fry rpi, or at least make it unstable then by just connecting them? Maybe 3W is combined power of 2 modules, which will make one of them barely use 500 mA? – user2872173 Oct 23 '19 at 13:57
  • Well, I think 3W is for one LED module only. In other words, 6W total for two modules. Anyway, I think even drawing 1A from Rpi's 5V or 3V rail (pin 1 and pin 17) is very bad practice, even by my hobbyist's standards. So I strongly recommend not to draw power from Rpi's 5V or 3V3 rails. And for Rpi4B, which is itself rather hot already. So use a Lipo 18650 3.7V in my opinion is the best option for lazy hobbyists. – tlfong01 Oct 23 '19 at 14:28
  • @tlfong01 i suppose that i will firstly use mutimeter to measure this module, that i will be certain. I'm thinking about using one of them and it should be sufficient. I was hoping to make something like baby cam, so battery wouldn't be an option if i want it to run 24/7. – user2872173 Oct 23 '19 at 14:38
  • 1
    There is a chance of low power outage – Sohan Arafat Oct 24 '19 at 6:20
1

I presume by context you mean the 3V3 power rail pins (pin 1 and pin 17). They are NOT GPIO.

On the recent Pi models you can draw about an amp from the 3V3 power rail. On the earlier Pi models you can draw about 100 milliamps.

As an aside you can only safely draw about 20 milliamps from a single GPIO and about 50 milliamps in total from the GPIO.

Improve this answer
1
  • Pi from B+ to Pi3 have 1A regulator, so cannot provide 1A because some is required for 3.3V devices (SD Card, SOC etc). I have used up to 800mA. The PMIC on the Pi3B/A+, Pi4 can supply 1.5A. – Milliways Oct 23 '19 at 22:33
0

For anyone with similar problem: I've mesured the current, used by that module with multimeter and it showed no more than 200mA (i know there is photoresistor, so i measured everything in dark room with that photoresistor covered with black tape). So i soldered it with wires to Rpi ZeroW 3.3v power rail (than you @joan for clarification) to see if anything will blow up. After few days of testing i can say that my RaspberryPi ZeroW still lives. Temperature (vcgencmd measure_temp) was always around 50 degrees Celsius during streaming.

Disclaimer: I do not state it is fully safe, or at least done properly, i just want to say it works on my end and nothing bursted into flames... for now.

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.