fix: correct I2C address from 8-bit to 7-bit for periph.io#44
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ashitaka1 wants to merge 1 commit intoZaparooProject:mainfrom
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fix: correct I2C address from 8-bit to 7-bit for periph.io#44ashitaka1 wants to merge 1 commit intoZaparooProject:mainfrom
ashitaka1 wants to merge 1 commit intoZaparooProject:mainfrom
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The PN532 datasheet documents 0x48/0x49 as 8-bit addresses (including the R/W bit). periph.io and the Linux kernel expect 7-bit addresses, so the correct value is 0x24 (0x48 >> 1). Also add parseI2CPath() to handle composite detection paths (/dev/i2c-1:0x24) that the detection layer produces, and a hardware validation script for testing on Raspberry Pi.
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Summary
pn532WriteAddr = 0x48/pn532ReadAddr = 0x49) but periph.io'si2c.Dev.Addrexpects 7-bit addresses (passed directly to the LinuxI2C_SLAVEioctl). With0x48, the kernel puts0x90/0x91on the wire — an address nothing responds to.pn532Addr = 0x24(0x48 >> 1). periph.io handles the R/W bit automatically.parseI2CPath()to handle composite detection paths like/dev/i2c-1:0x24.scripts/i2c-validate.shfor hardware validation on Raspberry Pi.Testing
/dev/i2c-1i2cdetect -y 1shows device at0x24