Raspberry Pi Forums

What is going on?
The i2c table is full of addresses but I don't have any device connected.
Can anyone help me?

I'm trying to use a BPM085 device.
Raspberry pi 2
cat /etc/debian_version 8.0

pi@OM_Raspi ~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77

do you have appropriate pullups in place?

SDA is shorted to ground, so it is seeing an ack to everything.

Thanks guys for replying.
I'm still with the same trouble.
My setup of sensors:
3 DS18B20 (one wire) on gpio 24 with pullup resistor;
1 DHT22 on gpio 22 with pullup resistor;
Everything on 3.3v.
The BPM085 isn't pluggued.
SDA is disconnected. Not shorted to ground.
-------------------------------

The CONFIG.TXT:

pi@OM_Raspi ~ $ sudo cat /boot/config.txt
# For more options and information see
# http://www.raspberrypi.org/documentatio ... fig-txt.md
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
arm_freq=900

# Uncomment some or all of these to enable the optional hardware interfaces
dtparam=i2c1=on
dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=100000
dtparam=spi=on
dtoverlay=w1-gpio,gpiopin=24
dtparam=i2s=on
#enable_uart=1


# Uncomment this to enable the lirc-rpi module
#dtoverlay=lirc-rpi

# Additional overlays and parameters are documented /boot/overlays/README


# Enable audio (added by raspberrypi-sys-mods)
dtparam=audio=on

core_freq=500
sdram_freq=500
over_voltage=2

--------------------------------------------------------------
The file '/etc/modules' looks like this:

pi@OM_Raspi ~ $ cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.


i2c-bcm2708
i2c-dev

-----------------------------------------------------------------
Still showing the table full
I don't have any i2c device connected yet.


Last login: Wed Dec 14 11:02:41 2016
pi@OM_Raspi ~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77

Any advice?

Put a pull-up on SDA.
PeterO

It looks like you've got an I²C device on the bus that's permanently pulling SDA to GND. Check your wiring, have you got a device with SCL & SDA reversed.

Have you put your 1-wire device on the wrong pin (#5 rather than #7)?

http://pinout.xyz

/Etc/modules should NOT include i2c_bcm2708. Device tree should load that for you.

PeterO wrote:Put a pull-up on SDA.
PeterO

Its already done.

You have wired something incorrectly. Without a photo we can only guess at what.

DougieLawson wrote:It looks like you've got an I²C device on the bus that's permanently pulling SDA to GND. Check your wiring, have you got a device with SCL & SDA reversed.

Have you put your 1-wire device on the wrong pin (#5 rather than #7)?

http://pinout.xyz

Thanks for your suport.
The SDA and SCL isn't reverse and using a pullup resistor.
the 1-wire was on gpio 24 (pin 18) and I changed to gpio 26 (pin 17), using a pullup resistor too.

I run some test:
1) I disconnect all devices and the i2c table runs ok, complete empty. I connect the BPM085 and the table show up just with te address 77 (0x77 = BPM085) . Fine.
2) I connect the DHT22 on gpio 22 (pin 15), reboot the Rpi and the DHT22 looks like fine. But the Table of i2cdetect show up full again.
3) I disconnect the DHT, reboot, then the table show up fine, just with address 77 (0x77 = BMP085) again.
4) I connect the 3 BS18B20 (1-wire) gpio 24 (pin 18) , reboot, and the table i2c is full again.
5) I disconnect the 3 BS18B20 and conect a single led on gpio 5 (pin 29) restart the Pi and the table show up full again, and again and again and again.

Conclusion for me:
This device runs just lonely. They don't like companion. I guess...It's so sad...

Another one advice, please???

6by9 wrote:/Etc/modules should NOT include i2c_bcm2708. Device tree should load that for you.

Tanks for your suport.
I removed the i2c_bcm2708 from etc/modules.


pi@OM_Raspi ~ $ cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.

i2c-dev

But still with the same problem.

pi@OM_Raspi ~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77

Where's the photo of your wiring. Nobody can help without that.

DougieLawson wrote:Where's the photo of your wiring. Nobody can help without that.

Photos on http://www.omarinho.com.br/bpm085.html

Everything was double-checked . All single connection, condutivity etc.
photo #1
This photo is only with BPM085 connected.
SDA >> gpio 02 (pin 03) yelow wire.
SCL >> SCL gpio 03 (pin 05) orange wire.
Pullup resistor 10k btw SDA and 3.3v.
GND brown wire
and 3.3v red wire.

photo #2
Screen with Home Assistant running showing no devices connected and terminal shows that bpm085 shows up : address 77 (0x77)

photo #3
Devices connected : BPM085 and
DHT22: 3.3v, gnd, gpio22 (pin15)
DS18b20 (one wire): 3.3v, gnd, gpio 26 (pin37)

Photo #4
Screen showing Home Assistant with DHT working fine and Terminal showing i2c table full of address.

photo #5
Screen showing Home Assistant with DHT and 2 DS18b20 working fine and Terminal showing i2c full of address.

Can't see how that's wired to your RPi.

Its hard to make out any wiring details from those photos.

As a matter of interest could you enter the following commands when you see the full I2C table.

sudo pigpiod
pigs mg 2 mg 3

joan wrote:As a matter of interest could you enter the following commands when you see the full I2C table.

sudo pigpiod
pigs mg 2 mg 3

Thanks for your patience.

Last login: Thu Dec 15 09:10:19 2016
pi@OM_Raspi ~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77
pi@OM_Raspi ~ $ sudo pigpiod
pi@OM_Raspi ~ $ pigs mg 2 mg 3
1
4

Enter the following command and try the i2cdetect again.

pigs m 2 0 # zero

joan wrote:Enter the following command and try the i2cdetect again.

pigs m 2 0 # zero

0? That appears to set it to an input, when it needs to be ALT0 for I2C, which would be a value of 4.

6by9 wrote:

joan wrote:Enter the following command and try the i2cdetect again.

pigs m 2 0 # zero

0? That appears to set it to an input, when it needs to be ALT0 for I2C, which would be a value of 4.

The pigs m command uses r for input, w for output, 0-5 for ALT0 - ALT5.

joan wrote:Enter the following command and try the i2cdetect again.

pigs m 2 0 # zero

pi@OM_Raspi ~ $ pigs m 2 0 # zero
pi@OM_Raspi ~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- 77

It's Work! Great! Thank you so very much, joan .
What happened? Teach me, I'm an eternal apprentice.

@omarinho

I think our current guess would be your Home Assistant software is mucking up I2C by changing GPIO 2 (SDA) from mode ALT0 (I2C) to mode write.

You probably need to ask Home Assistant for a fix.

joan wrote:@omarinho

I think our current guess would be your Home Assistant software is mucking up I2C by changing GPIO 2 (SDA) from mode ALT0 (I2C) to mode write.

You probably need to ask Home Assistant for a fix.

Thank you again. Have a great nice day.

All of you who tried to help me . Thanks so much. Joan solved the problem.
Have all of you a nice day.