Wednesday, September 25, 2019

Poor man's PoE for Raspberry pi-3/4 under ~$2


Warning: This blog is about powering your raspberry pi-3/4 over ethernet cable(length upto 100Meters), It uses Passive PoE mechanism where T568b wire colors are.. 
Blue/Blue-White         ==> +(positive) terminal of DC supply
Brown-White/Brown  ==> -(negetive) terminal of DC supply

If you dont know what is a passive PoE, then dont proceed!!!, instead buy a proper PoE Hat for Raspberry pi-3.

If you are a tinkerer/hw-enthusiest/diy-hobbyist(and you know what you are doing), here is what you need,

1)PoE Injector cable(costs less than 80cents)



2)DC-DC buck converter from aliexpress that costs less than 50cents(Look for Hesai brand, 12v-24v input and 5V/3A Output).


3)female-to-female jumper wire(cut into 4 pieces) and solder as shown in the picture



4)Cover DC-DC converter in a heatshrink sleev, and connect to raspi-3 as shown.

5)Feed 12v-DC and  Network-connection to the PoE Injector and connect CAT-5 cable(upto 100m) between Injector cable and Raspberry-Pi-3 as shown below



8 comments:

  1. Using a 1N4148 diode for reverse polarity protection might be a bit under-specced: the Pi-3 + peripherals can draw something near 800mA under heavy load and the 1N4148 is rated at 300mA max continuous current, 500mA max repetitive peak. Something like a 1N5817/1N5819 schottky diode would be better - and maybe a 3A 1N5822 if there's any power-hungry USB peripherals. That buck converter claims to be good up to 3A.

    Ref: https://raspberrypi.stackexchange.com/questions/43285/raspbe...

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  2. Reference was truncated - try:

    https://raspberrypi.stackexchange.com/questions/43285/raspberry-pi-3-vs-pi-2-power-consumption-and-heat-dissipation

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  3. Instead of soldering 9v then adjusting the pot, use the pcb/module as it was meant to be used. Cut the ADJ trace and solder the 5v.
    See the picture here https://www.electronics.com.bd/image/cache/catalog/module/new/Mini-DC-DC-12-24V-To-5V-3A-Step-Down-Power-Supply-Module-Voltage-Buck1-1000x1000.jpg
    Alternative instructions here https://i.pinimg.com/originals/e5/30/a7/e530a729067f0bd997f077ff53729f5f.jpg

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  4. Thanks NickG for the hint, i will update this blog.

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  5. Nice scheme, I'll try to create something similar

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  6. Hi thank you for the guide. I followed it religiously only to get to the last step where I opened up the case for my RPI3 model B v 1.2 and found out I did not have the PoE pins required.

    Turns out this capability was only added in the RPI3 model B+ (https://www.rs-online.com/designspark/raspberry-pi-3-model-b-vs-3-model-b).

    Still I got to learn a few things on the way and get frustrated at my soldering skills :)

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  7. A Poor Man's Raspberry Pi PoE HAT that You can Build on Your Own. Raspberry Pi-based systems require internet connectivity to work at full ...Warning: This blog is about powering your raspberry pi-3/4 over love language test ethernet cable(length upto 100Meters), It uses Passive PoE mechanism where T568 bWhen the Raspberry Pi 3 Model B+ was announced in March of 2018, ... out a solution he calls “poor man's PoE” together for about two buck Poor man's PoE for Raspberry pi-3/4 under ~$2. Sat Sep 28, 2019 10:09 am. Just thought of sharing this low cost Passive PoE hack:

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  8. Je tiens à vous remercier pour vos mots inspirants qui font une différence dans ma vie. J'utilise des CPS Click pour m'entraîner et améliorer ma rapidité de clic, c'est impressionnant de voir les progrès au fil du temps.

    ReplyDelete