Hi Phil,
Am 28.01.2016 um 23:49 schrieb Phil:
A few questions:
1) What has changed in your system? Have you ever been able to use the PiGlow?
please avoid top-posting. I'm using I2C just for a short time, so i
don't know if there was a different behavior before. I tested the PiGlow
with the following kernel versions:
Raspbian Wheezy 3.18
Raspbian Jessie 4.1.13
Mainline 4.5rc-1
All of them show the same detect behavior (see below).
Writing to the SN3218 works good, i can enable and disable the LEDs ...
But i can't read back any values.
I've replaced the PiGlow with a Adafruit Si1145. After that the chip is
detected in both cases, but the error messages (i2c transfer failed)
still appear.
2) What is the state of the GPIOs?
What do you mean? configuration of both I2C0 pins?
Do you want a register dump?
Thanks
Stefan
Phil
On 28 Jan 2016 9:43 p.m., Stefan Wahren <info@xxxxxxxxxxxxxx> wrote:
Hi,
i'm using a Raspberry Pi B (rev 1) and Linux kernel 4.5rc-1. I have
connected a PiGlow (SN3218 at address 0x54) to the P1 Header. The I2C
bus clock is set to 100 kHz. Every time i want to read data from i2c0
the following error appear:
[ 94.343612] i2c-bcm2835 20205000.i2c: i2c transfer failed: 100
According to the BCM2835 datasheet this should be an ERR ACK (Slave has
not acknowledged its address).
i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
i2cdetect -q -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- 54 -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Strangly writing data to the SN3218 works.
Does anyone have an explanation for this error?
Regards
Stefan
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