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Diffstat (limited to 'i2c/a0_dummy_write/README')
| -rw-r--r-- | i2c/a0_dummy_write/README | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/i2c/a0_dummy_write/README b/i2c/a0_dummy_write/README index 0683e8a..d7fe4e7 100644 --- a/i2c/a0_dummy_write/README +++ b/i2c/a0_dummy_write/README @@ -1,5 +1,36 @@ -This is a small chunk of I2C protocol data. +------------------------------------------------------------------------------- +Dummy I2C writes +------------------------------------------------------------------------------- -The master tries to talk to a slave device, but there is none on the bus, -no there are no answers. +This an example capture of some dummy I2C traffic, where the master writes +to a slave at address 0x51 (or 0x2a, if the read/write bit is included) +in an infinite loop. The slave does not respond. + + +Logic analyzer setup +-------------------- + +The logic analyzer used for capturing was a ChronoVu LA8 at a sample rate +of 1MHz. The logic analyzer probes were connected to the I2C pins like this: + + Probe RTC chip pin + ------------------------ + 0 (green) SCL + 1 (orange) SDA + GND GND + + +Data +---- + +This is what the decoded data should look like: + + - S Wr:0xa2 A 0x55 A 0x66 A P + + - The abbreviations used above: S = Start, Wr = Write, A = ACK, P = Stop + +The sigrok command line used was: + + sigrok-cli -d 0:samplerate=1mhz --samples 8388608 \ + -p '1=SCL,2=SDA' -o a2_dummy_write.sr |