4 ms·

Wonder why they went with the barrel jack for power over USB, as the latter seems more prevalent...?

by donw 6y ago

Havoc 6y ago
I'm guessing to side-step the issues the raspberries are having. USB-C can carry enough juice but there are just so many crap cables out there & then the device gets blamed by the user because it's such a subtle failure mode
- Roritharr 6y ago
  I'd second this. I tried yesterday using the brand new cable supplied with my Google Stadia Controller to use to connect my Phone to my car. It worked! Android Auto showed up - only to fail after 20 seconds. No turning around and reseating helped although the connection was physically better than the cable I was trying to replace. USB-C cables are just a mess.
wyldfire 6y ago
Keeping a cheap BOM, I'd bet. No licensing fees, conformance tests, etc.
nfriedly 6y ago
Micro usb would have trouble delivering enough power because of its limitation to 5 volts. USB type-c could do higher voltage, but it requires power delivery circuitry which adds to the cost and complexity. Well I still prefer USBC, I can understand the choice of a barrel jack here: it's simple, reliable, and less expensive.
- AstroJetson 6y ago
  I agree with the issue, but I'm sad since there isn't a "standard" size, so I'm back to collecting wall warts to power things again.
  - imtringued 6y ago
    You're not supposed to use a random USB charger with SBCs. Always use the manufacturer provided PSU even if it is just a USB PSU. Random chargers tend to be of inferior quality because the devices they are charging have an integrated battery that filters any noise and prevents shutdowns from temporary spikes. The usb power source being unreliable is basically the biggest reason why SD cards get corrupted in raspberry pis. There is also the obvious problem the initial batch of the Raspberry Pi 4 suffered from. The Raspberry Pi foundation does not test their SBCs with anything other than the official PSU.
  - nfriedly 6y ago
    My dad had a really cool "universal laptop charger". It had a dial on the brick that set the voltage from like 3 to 30 volts, and then it had about 20 different tips, so it could power just about anything.
numpad0 6y ago
Using USB plug for power makes sense so long as cables and power sources for other device can be reused. I suppose they don’t expect that to be the case.
analog31 6y ago
The current that can be drawn by a fully loaded machine can overcome what's reasonable via a mainstream USB cable. Even on the RPi, I've had to bring power in via the GPIO in order to run a USB powered hard drive on the other side. An amusing but possibly obscure benefit of higher voltage is being able to run a mainstream audio amplifier from the same power supply. My "home stereo" presently requires two power supplies for this reason.

Wonder why they went with the barrel jack for power over USB, as the latter seems more prevalent...?

by donw 6y ago

Wonder why they went with the barrel jack for power over USB, as the latter seems more prevalent...?

I'm guessing to side-step the issues the raspberries are having. USB-C can carry enough juice but there are just so many crap cables out there & then the device gets blamed by the user because it's such a subtle failure mode

Roritharr 6y ago
I'd second this. I tried yesterday using the brand new cable supplied with my Google Stadia Controller to use to connect my Phone to my car. It worked! Android Auto showed up - only to fail after 20 seconds. No turning around and reseating helped although the connection was physically better than the cable I was trying to replace. USB-C cables are just a mess.

wyldfire 6y ago

Keeping a cheap BOM, I'd bet. No licensing fees, conformance tests, etc.

nfriedly 6y ago

Micro usb would have trouble delivering enough power because of its limitation to 5 volts. USB type-c could do higher voltage, but it requires power delivery circuitry which adds to the cost and complexity. Well I still prefer USBC, I can understand the choice of a barrel jack here: it's simple, reliable, and less expensive.

AstroJetson 6y ago
I agree with the issue, but I'm sad since there isn't a "standard" size, so I'm back to collecting wall warts to power things again.
- imtringued 6y ago
  You're not supposed to use a random USB charger with SBCs. Always use the manufacturer provided PSU even if it is just a USB PSU. Random chargers tend to be of inferior quality because the devices they are charging have an integrated battery that filters any noise and prevents shutdowns from temporary spikes. The usb power source being unreliable is basically the biggest reason why SD cards get corrupted in raspberry pis. There is also the obvious problem the initial batch of the Raspberry Pi 4 suffered from. The Raspberry Pi foundation does not test their SBCs with anything other than the official PSU.
- nfriedly 6y ago
  My dad had a really cool "universal laptop charger". It had a dial on the brick that set the voltage from like 3 to 30 volts, and then it had about 20 different tips, so it could power just about anything.

numpad0 6y ago

Using USB plug for power makes sense so long as cables and power sources for other device can be reused. I suppose they don’t expect that to be the case.

analog31 6y ago

The current that can be drawn by a fully loaded machine can overcome what's reasonable via a mainstream USB cable. Even on the RPi, I've had to bring power in via the GPIO in order to run a USB powered hard drive on the other side. An amusing but possibly obscure benefit of higher voltage is being able to run a mainstream audio amplifier from the same power supply. My "home stereo" presently requires two power supplies for this reason.