[2024-feb-29] Sad news: Eric Layton aka Nocturnal Slacker aka vtel57 passed away on Feb 26th, shortly after hospitalization. He was one of our Wiki's most prominent admins. He will be missed.
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howtos:hardware:arm:interfacing_i2c_devices [2023/05/28 14:31 (UTC)] – [Hacking I2C in PC DIMM modules] louigi600 | howtos:hardware:arm:interfacing_i2c_devices [2023/05/28 14:46 (UTC)] (current) – [Hacking I2C in PC DIMM modules] louigi600 | ||
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and I double-checked that these pins are actually connected to the respective pins on the SO-DIMM module. | and I double-checked that these pins are actually connected to the respective pins on the SO-DIMM module. | ||
I was particularly lucky and this module has unused solder pads for a second eprom unit, making it super easy to solder some wires on the unused pats to hack another I2C device into the bus. | I was particularly lucky and this module has unused solder pads for a second eprom unit, making it super easy to solder some wires on the unused pats to hack another I2C device into the bus. | ||
+ | |||
+ | Next you will need to identify which bus is the one reading the eprom on the DIMM modules, there is another tool that is part of the i2ctool that comes in handy for this: decode-dimms. | ||
+ | At the beginning it will sit out a line like this | ||
+ | |||
+ | Decoding EEPROM: / | ||
+ | |||
+ | The last part 0-0050 identifies bus 0 address 50. | ||
+ | |||
+ | Looking at what devices are present on bus 0 | ||
+ | |||
+ | # i2cdetect -y 0 | ||
+ | | ||
+ | 00: 08 -- -- -- -- -- -- -- | ||
+ | 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- | ||
+ | 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- | ||
+ | 30: 30 -- -- -- -- 35 UU UU -- -- -- -- -- -- -- -- | ||
+ | 40: -- -- -- -- 44 -- -- -- -- -- -- -- -- -- -- -- | ||
+ | 50: UU -- 52 -- -- -- -- -- -- -- -- -- -- -- -- -- | ||
+ | 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- | ||
+ | 70: -- -- -- -- -- -- -- -- | ||
+ | |||
+ | So as long as whatever device I hack into this bus does not use address 8, | ||
+ | |||