So we got a Powered USB Hub thinking we could use the Pi for a media share, but the HDD refuses to be detected. I saw this question asked countless times on Google and Stack Exchange, but they are all old threads or the people were just making rookie mistakes, we've been at this for a while now and we can't figure out the issue.
We checked the voltage and Amps (coming in the RPi power supply) with a USB meter and we have: 5.01V 0.825A
We tried with USB Flash drives = all good
We tried the HDD directly on the Pi = no good
We tried the HDD directly in the hub without power = no good
We tried the HDD directly in the hub with power = no good
We tried the hard drive in a laptop = all good, working
We tried several HDD sizes 1TB-4TB = no good
We tried FAT32 and HFS = no good
We tried unplugging everything except the screen = no good
Here's the output of
dmesg after plugging the HDD:
[ 58.311593] Voltage normalised (0x00000000) [ 60.391578] Under-voltage detected! (0x00050005) [ 64.551542] Voltage normalised (0x00000000) [ 71.756436] w1_master_driver w1_bus_master1: Attaching one wire slave 00.800000000000 crc 8c [ 71.763651] w1_master_driver w1_bus_master1: Family 0 for 00.800000000000.8c is not registered. [ 77.031561] Under-voltage detected! (0x00050005) [ 81.191562] Voltage normalised (0x00000000) [ 98.071507] usb 1-1.2: new high-speed USB device number 6 using dwc_otg [ 98.201860] usb 1-1.2: New USB device found, idVendor=1a40, idProduct=0101 [ 98.201875] usb 1-1.2: New USB device strings: Mfr=0, Product=1, SerialNumber=0 [ 98.201884] usb 1-1.2: Product: USB 2.0 Hub [ 98.202600] hub 1-1.2:1.0: USB hub found [ 98.202690] hub 1-1.2:1.0: 4 ports detected [ 100.071580] usb 1-1.2.3: new high-speed USB device number 7 using dwc_otg [ 100.213176] usb 1-1.2.3: New USB device found, idVendor=0bc2, idProduct=ab2a [ 100.213195] usb 1-1.2.3: New USB device strings: Mfr=2, Product=3, SerialNumber=1 [ 100.213204] usb 1-1.2.3: Product: BUP Fast HDD [ 100.213212] usb 1-1.2.3: Manufacturer: Seagate [ 100.213220] usb 1-1.2.3: SerialNumber: NA7F2Y8T [ 100.214038] usb-storage 1-1.2.3:1.0: USB Mass Storage device detected [ 100.214403] scsi host0: usb-storage 1-1.2.3:1.0 [ 101.272550] scsi 0:0:0:0: Direct-Access Seagate BUP Fast HDD 9408 PQ: 0 ANSI: 6 [ 101.274890] sd 0:0:0:0: [sda] Spinning up disk... [ 101.295262] sd 0:0:0:0: Attached scsi generic sg0 type 0 [ 101.991590] Under-voltage detected! (0x00050005) [ 102.311504] . [ 103.351513] . [ 104.391503] . [ 105.431514] . [ 106.471504] . [ 107.511496] . [ 108.551504] . [ 109.591499] . [ 110.631486] . [ 111.671505] . [ 112.711512] . [ 113.751497] . [ 114.791498] . [ 115.831499] . [ 116.871481] . [ 117.911516] . [ 118.631544] Voltage normalised (0x00000000) [ 118.951495] .
The screen we are using is the official RPi 7" HDMI screen and we unfortunately need to leave it plugged in the RPi to have display, even plugging the screen in an external USB power source still shows a blank screen. I'm wondering if the screen is drawing too much power but then again, we have a powered USB hub so it shouldn't be a problem.
UPDATE AND SOLUTION: Ater checking the current a hard drive gets from a computer or from the wall output (0.7A-1A) and comparing it with the powered USB hub on the RPi (0.3A-0.4A), we figured out the hub was probably crappy (even if we paid 20$) and might have a resistance in there to prevent too much power from getting in. So we built our own "redneck engineering" USB hub in the picture below, which is basically just the regular HDD black USB cable soldered to GND and VCC of the transparent dual USB cable from an old HDD (One would probably be enough). Then we plug the transparent cable in an external USB source.