3 ms·

I'm very skeptical of PoE now after 3 PoE adapters killed 3 Raspberry Pis I have. I wouldn't want to risk something more expensive to that shit. At this point

by dheera 3y ago

I'm very skeptical of PoE now after 3 PoE adapters killed 3 Raspberry Pis I have. I wouldn't want to risk something more expensive to that shit. At this point I'd rather just have straight up 19V + and - cables bundled together with the Ethernet with some heatshrink around the whole thing to make it look like 1 cable.

CameronNemo 3y ago
You sure you want to blame poe as a whole instead of the RPI hat?
- dheera 3y ago
  Sure it could be the RPi hat, but it just means the standard is so complicated that people don't implement it correctly. I wouldn't trust the hat or whatever you call it for Mac Mini.
  - wolrah 3y ago
    > Sure it could be the RPi hat, but it just means the standard is so complicated that people don't implement it correctly. Or there are ways to cheap out on a PoE device that may work in some cases but don't fully and properly implement the standard. The standard is widely used in VoIP phones, wireless access points, security cameras, and all sorts of other networked devices that get installed in places that may not have nearby power outlets or where a single wire solution is beneficial. Personally I have three Pis that have been on PoE their entire lives and have had no problem, but I used a name brand PoE hat (the Waveshare hat with the OLED display) and am powering them from a mainstream PoE switch. If you're using some random AliExpress hat with janky injectors you get what you pay for. > I wouldn't trust the hat or whatever you call it for Mac Mini. Almost any large commercial building has had hardware running on PoE that costs more than the average Mac Mini for years. Most PTZ cameras for example, high-end directional wireless bridges, even some nicer wireless access points.
    - dheera 3y ago
      I mean, one of my hats that fried one of my Pis was a Waveshare hat. This one actually https://www.amazon.com/gp/product/B0974TK3KD/ https://www.amazon.com/gp/product/B0974TK3KD/ PoE operates at a pretty high voltage (almost half of line voltage!) and Waveshare products aren't UL listed.
      - NavinF 3y ago
        >PoE operates at a pretty high voltage No, it operates at ELV (extra-low voltage): https://en.wikipedia.org/wiki/Extra-low_voltage https://en.wikipedia.org/wiki/Extra-low_voltage The whole point of PoE, 48V PD USB-C, and similar tech is that they don't need to be UL listed. PoE is also electronically current limited unlike mains power so you can't pull 200A to start a motor nor can you start fires without a lot of effort. That's assuming you use a real PoE switch that negotiates power levels, not cheap passive injectors. Anyway that hat has some bad reviews claiming DoA, missing components, and dead Pis. Why not get the official hat? https://www.raspberrypi.com/products/poe-hat/ https://www.raspberrypi.com/products/poe-hat/
  - NovemberWhiskey 3y ago
    You're dealing with the same manufacturers that won't even bother to include the USB C termination resistors required to make "USB C" charging ports on their devices work with actual USB-compliant PD. You're talking about the kind of part that's so cheap that adding five of them is going to round down below a penny in your BOM. The kind of manufacturer that, if it had a motto, that motto would be "no corner too cheap to cut".
- SV_BubbleTime 3y ago
  It’s definitely that. PoE is fine and the issue surely lies on some $5 Chinese rasppi part with little buffering and protection circuitry.
haswell 3y ago
PoE is used extensively in network deployments involving rather expensive hardware. I understand the instinct to avoid it at this point, but I’m curious what happened in your case because I’ve never experienced issues. I did work somewhere where someone fried equipment by incorrectly terminating a batch of Ethernet cables thereby sending voltage to the wrong place.
- bob778 3y ago
  That should only be possible if using non-standard "passive" PoE? 802.3bt has negotiation specifically to prevent faulty cables/devices from being powered.
wil421 3y ago
I have 13-15 devices running over PoE at my house and all of them work just fine. Everything from the high end Ubiquiti gear to raspberry 3/4 PoE hats. It’s powered by a Unifi 24 port PoE switch. The only time I had issues was with a 2 mesh APs and sketchy power at a condo that has minor power outages due to thunderstorms. I brought the devices back home and they work fine, the new device doesn’t have an issue. I was curious if a UPS would’ve smoothed the power blips but the new AP restarts and connects just fine.
NavinF 3y ago
PoE switches and devices are widely used in industry. I suspect your 3 PoE adapters are "passive PoE" consumer crap that doesn't meet spec
Alupis 3y ago
What kind of PoE Adapter/Hat did you use? From memory, and it's been a few years/models... but the GPIO pins, including the 5V input pin bypassed all of the circuit protection fuses and what-not the normal barrel jack had. It wasn't uncommon for people to roast their RPi with incorrectly done, or poor quality GPIO powering devices.
- hnbad 3y ago
  This is still true. There are ample warnings to be careful when using the GPIO as input because of this. The hat probably passed on some variance that is supported by actual consumer devices and fried the RasPi because it has no protections.
epcoa 3y ago
Don’t buy eBay junk and blame it on the standard - which is used by tons of high end commercial equipment and is more appropriately a commercial feature - PoE isn’t cheap - if it is that probably explains your poor results.

by dheera 3y ago

CameronNemo 3y ago

You sure you want to blame poe as a whole instead of the RPI hat?

dheera 3y ago
Sure it could be the RPi hat, but it just means the standard is so complicated that people don't implement it correctly. I wouldn't trust the hat or whatever you call it for Mac Mini.
- wolrah 3y ago
  > Sure it could be the RPi hat, but it just means the standard is so complicated that people don't implement it correctly. Or there are ways to cheap out on a PoE device that may work in some cases but don't fully and properly implement the standard. The standard is widely used in VoIP phones, wireless access points, security cameras, and all sorts of other networked devices that get installed in places that may not have nearby power outlets or where a single wire solution is beneficial. Personally I have three Pis that have been on PoE their entire lives and have had no problem, but I used a name brand PoE hat (the Waveshare hat with the OLED display) and am powering them from a mainstream PoE switch. If you're using some random AliExpress hat with janky injectors you get what you pay for. > I wouldn't trust the hat or whatever you call it for Mac Mini. Almost any large commercial building has had hardware running on PoE that costs more than the average Mac Mini for years. Most PTZ cameras for example, high-end directional wireless bridges, even some nicer wireless access points.
  - dheera 3y ago
    I mean, one of my hats that fried one of my Pis was a Waveshare hat. This one actually https://www.amazon.com/gp/product/B0974TK3KD/ https://www.amazon.com/gp/product/B0974TK3KD/ PoE operates at a pretty high voltage (almost half of line voltage!) and Waveshare products aren't UL listed.
    - NavinF 3y ago
      >PoE operates at a pretty high voltage No, it operates at ELV (extra-low voltage): https://en.wikipedia.org/wiki/Extra-low_voltage https://en.wikipedia.org/wiki/Extra-low_voltage The whole point of PoE, 48V PD USB-C, and similar tech is that they don't need to be UL listed. PoE is also electronically current limited unlike mains power so you can't pull 200A to start a motor nor can you start fires without a lot of effort. That's assuming you use a real PoE switch that negotiates power levels, not cheap passive injectors. Anyway that hat has some bad reviews claiming DoA, missing components, and dead Pis. Why not get the official hat? https://www.raspberrypi.com/products/poe-hat/ https://www.raspberrypi.com/products/poe-hat/
- NovemberWhiskey 3y ago
  You're dealing with the same manufacturers that won't even bother to include the USB C termination resistors required to make "USB C" charging ports on their devices work with actual USB-compliant PD. You're talking about the kind of part that's so cheap that adding five of them is going to round down below a penny in your BOM. The kind of manufacturer that, if it had a motto, that motto would be "no corner too cheap to cut".
SV_BubbleTime 3y ago
It’s definitely that. PoE is fine and the issue surely lies on some $5 Chinese rasppi part with little buffering and protection circuitry.

haswell 3y ago

PoE is used extensively in network deployments involving rather expensive hardware. I understand the instinct to avoid it at this point, but I’m curious what happened in your case because I’ve never experienced issues. I did work somewhere where someone fried equipment by incorrectly terminating a batch of Ethernet cables thereby sending voltage to the wrong place.

bob778 3y ago
That should only be possible if using non-standard "passive" PoE? 802.3bt has negotiation specifically to prevent faulty cables/devices from being powered.

wil421 3y ago

I have 13-15 devices running over PoE at my house and all of them work just fine. Everything from the high end Ubiquiti gear to raspberry 3/4 PoE hats. It’s powered by a Unifi 24 port PoE switch. The only time I had issues was with a 2 mesh APs and sketchy power at a condo that has minor power outages due to thunderstorms. I brought the devices back home and they work fine, the new device doesn’t have an issue. I was curious if a UPS would’ve smoothed the power blips but the new AP restarts and connects just fine.

NavinF 3y ago

PoE switches and devices are widely used in industry. I suspect your 3 PoE adapters are "passive PoE" consumer crap that doesn't meet spec

Alupis 3y ago

What kind of PoE Adapter/Hat did you use? From memory, and it's been a few years/models... but the GPIO pins, including the 5V input pin bypassed all of the circuit protection fuses and what-not the normal barrel jack had. It wasn't uncommon for people to roast their RPi with incorrectly done, or poor quality GPIO powering devices.

hnbad 3y ago
This is still true. There are ample warnings to be careful when using the GPIO as input because of this. The hat probably passed on some variance that is supported by actual consumer devices and fried the RasPi because it has no protections.

epcoa 3y ago

Don’t buy eBay junk and blame it on the standard - which is used by tons of high end commercial equipment and is more appropriately a commercial feature - PoE isn’t cheap - if it is that probably explains your poor results.