Re: [flashrom] Some troubles connecting a W25X40ALSNIG flash chip to raspberry pi (v3 model B)
Hi,
On 06.03.2018 00:20, Jesse Li wrote:
Hey,
I'm trying to read from and flash to a W25X40ALSNIG [0] that's still mounted to its hard drive PCB. Following the table from the raspberry pi wiki page [1], and assuming the raspberry pi pin numbers it mentions are physical pin numbers (and not the pi's strange GPIO numbering scheme) I connected the legs of the flash chip to the raspberry pi's GPIO pins. However, when the two are attached, the pi won't boot (it'll show the three raspberries in the corner, then it shuts off). I've isolated this to the VCC (connected to header 17, 3v3) and GND (connected to header 25, GND) , where having all of the legs of the flash chip detached from the pi except for those two will reproduce my problem (I hope testing that didn't actually kill the chip). What am I missing?
the circuitry of your hard drive is most likely not prepared for powe- ring the flash chip directly at its VCC pin. You probably power all 3V3 parts on that PCB which is too much for your RPi's PSU / voltage conver- ter.
Killing the SPI flash is unlikely. I can't say the same about other chips on the board, though. Reading the flash while the hard drive is up and running, probably also isn't a good idea. You could desolder the flash chip, or try a stronger PSU, both ways have chances to break some- thing.
Nico
Thank you! I swapped out my phone charger for my iPad's wall wart to power the raspberry pi, and I did some power-saving stuff like installing raspbian lite, disabling LEDs and radios, and accessing the pi via SSH rather than a monitor and HDMI. And it worked! The drive seems to be functioning perfectly fine even after doing some reads/writes on the chip.
On Tue, Mar 6, 2018 at 3:42 PM, Nico Huber nico.h@gmx.de wrote:
Hi,
On 06.03.2018 00:20, Jesse Li wrote:
Hey,
I'm trying to read from and flash to a W25X40ALSNIG [0] that's still mounted to its hard drive PCB. Following the table from the raspberry pi wiki page [1], and assuming the raspberry pi pin numbers it mentions are physical pin numbers (and not the pi's strange GPIO numbering scheme) I connected the legs of the flash chip to the raspberry pi's GPIO pins. However, when the two are attached, the pi won't boot (it'll show the
three
raspberries in the corner, then it shuts off). I've isolated this to the VCC (connected to header 17, 3v3) and GND (connected to header 25, GND) , where having all of the legs of the flash chip detached from the pi
except
for those two will reproduce my problem (I hope testing that didn't actually kill the chip). What am I missing?
the circuitry of your hard drive is most likely not prepared for powe- ring the flash chip directly at its VCC pin. You probably power all 3V3 parts on that PCB which is too much for your RPi's PSU / voltage conver- ter.
Killing the SPI flash is unlikely. I can't say the same about other chips on the board, though. Reading the flash while the hard drive is up and running, probably also isn't a good idea. You could desolder the flash chip, or try a stronger PSU, both ways have chances to break some- thing.
Nico
-
Jesse Li -
Nico Huber