I'm trying to have a DS18B20 working with my Raspberry Pi Model B Revision 1.0, and it doesn't work.
No matter what I try I still see nothing in /sys/bus/w1/devices/ besides:
pi@raspberrypi ~ $ ls /sys/bus/w1/devices/
00-280000000000  00-c80000000000  w1_bus_master1
The 00-xxx are changing every once in a while.
- I have tried with dtoverlay=w1-gpio in /boot/config.txt (with pullup, without, with gpiopin without...).
 - I've tried to disable DT but no luck.
 - I've also tried to go back to an old kernel using rpi-update ba43047bec24d5f0a4150f09a37884240f8926d2 no luck either (and it breaks my wifi dongle).
 - I've tried to use port 4 (default) and port 5.
 - I've tried one 2 metter sensor waterproof sensor from aliexpress and a 1 metter waterproof sensor from amazon.
 
FYI, I'm able to switch on and off leds from port 4 and 5 if I switch them in out mode (and disable the w1-gpio).
Interesting parts of dmesg:
[   17.175551] Driver for 1-wire Dallas network protocol.
[   17.207547] w1-gpio onewire@0: gpio pin 4, external pullup pin -1, parasitic power 0
[   17.207613] w1_add_master_device: set_pullup requires write_byte or touch_bit, disabling
[...]
[   68.290649] w1_master_driver w1_bus_master1: Family 0 for 00.800000000000.8c is not registered.
[  127.602306] w1_master_driver w1_bus_master1: Family 0 for 00.400000000000.46 is not registered.
[  174.963571] w1_master_driver w1_bus_master1: Family 0 for 00.c00000000000.ca is not registered.
[  246.225280] w1_master_driver w1_bus_master1: Family 0 for 00.200000000000.23 is not registered.
[  305.536334] w1_master_driver w1_bus_master1: Family 0 for 00.a00000000000.af is not registered.
and so on.
Some details:
pi@raspberrypi ~ $ lsmod | grep w1
w1_gpio                 4295  0
wire                   31227  1 w1_gpio
pi@raspberrypi ~ $ cat /boot/config.txt | grep -v ^# | grep -v ^$
arm_freq=700
dtoverlay=w1-gpio
core_freq=250
sdram_freq=400
over_voltage=0
dtparam=spi=off
dtparam=i2c_arm=off
The breakboard I use: http://fr.aliexpress.com/item/1Set-Raspberry-PI-GPIO-Extension-Board-26-Pin-Cobbler-Extension-Flat-Ribbon-Cable-Wire-400pt-Breadboard/32341989972.html?isOrigTitle=true
With this wiring I can see that GPIO4 has power coming in, when I unplug it goes back to 0.
pi@raspberrypi ~ $ gpio readall
 +-----+-----+---------+------+---+-Model B1-+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   0 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5V      |     |     |
 |   1 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 0 |  7 || 8  | 1 | ALT0 | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
 |  21 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 1 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+-Model B1-+---+------+---------+-----+-----+
my linux version:
pi@raspberrypi ~ $ uname -a
Linux raspberrypi 4.1.13+ #826 PREEMPT Fri Nov 13 20:13:22 GMT 2015 armv6l GNU/Linux
For what it's worth, here's the output of the debug when adding:
dtoverlay=w1-gpio 
dtdebug=on
in the /boot/config.txt
$ sudo vcdbg log msg
000935.684: HDMI:EDID error reading EDID block 0 attempt 0
000936.947: HDMI:EDID error reading EDID block 0 attempt 1
000938.206: HDMI:EDID error reading EDID block 0 attempt 2
000939.464: HDMI:EDID error reading EDID block 0 attempt 3
000940.722: HDMI:EDID error reading EDID block 0 attempt 4
000941.981: HDMI:EDID error reading EDID block 0 attempt 5
000943.239: HDMI:EDID error reading EDID block 0 attempt 6
000944.498: HDMI:EDID error reading EDID block 0 attempt 7
000945.757: HDMI:EDID error reading EDID block 0 attempt 8
000947.014: HDMI:EDID error reading EDID block 0 attempt 9
000948.037: HDMI:EDID giving up on reading EDID block 0
000951.077: HDMI:Setting property pixel encoding to Default
000951.097: HDMI:Setting property pixel clock type to PAL
000951.117: HDMI:Setting property content type flag to No data
000951.137: HDMI:Setting property fuzzy format match to enabled
000966.166: gpioman: gpioman_get_pin_num: pin LEDS_RUNNING not defined
000966.190: gpioman: gpioman_get_pin_num: pin LEDS_NAND_ACTIVITY not defined
000966.212: gpioman: gpioman_get_pin_num: pin LEDS_USB_ACTIVITY not defined
000966.232: gpioman: gpioman_get_pin_num: pin LEDS_FATAL_ERROR not defined
000966.254: gpioman: gpioman_get_pin_num: pin LEDS_APP_OK not defined
000966.276: gpioman: gpioman_get_pin_num: pin LEDS_APP_FAILED not defined
000966.296: gpioman: gpioman_get_pin_num: pin LEDS_HDCP_AUTH not defined
000966.319: gpioman: gpioman_get_pin_num: pin LEDS_HDCP_UNAUTH not defined
000966.341: gpioman: gpioman_get_pin_num: pin LEDS_HDMI_ON not defined
000966.363: gpioman: gpioman_get_pin_num: pin LEDS_DVI_ON not defined
000966.385: gpioman: gpioman_get_pin_num: pin LEDS_HDMI_HPD_UP not defined
000966.406: gpioman: gpioman_get_pin_num: pin LEDS_REMOTE_CONTROL not defined
000966.427: gpioman: gpioman_get_pin_num: pin LEDS_ARM_CONTROLLED not defined
001120.885: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state                                                                                         instead
001120.912: hdmi: HDMI:>>>>>>>>>>>>>Rx sensed, reading EDID<<<<<<<<<<<<<
001121.321: hdmi: HDMI:EDID error reading EDID block 0 attempt 0
001122.588: hdmi: HDMI:EDID error reading EDID block 0 attempt 1
001123.851: hdmi: HDMI:EDID error reading EDID block 0 attempt 2
001125.114: hdmi: HDMI:EDID error reading EDID block 0 attempt 3
001126.377: hdmi: HDMI:EDID error reading EDID block 0 attempt 4
001127.640: hdmi: HDMI:EDID error reading EDID block 0 attempt 5
001128.903: hdmi: HDMI:EDID error reading EDID block 0 attempt 6
001130.166: hdmi: HDMI:EDID error reading EDID block 0 attempt 7
001131.429: hdmi: HDMI:EDID error reading EDID block 0 attempt 8
001132.692: hdmi: HDMI:EDID error reading EDID block 0 attempt 9
001133.718: hdmi: HDMI:EDID giving up on reading EDID block 0
001133.752: hdmi: HDMI: No lookup table for resolution group 0
001133.769: hdmi: HDMI: hotplug attached with DVI support
001133.829: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state                                                                                         instead
001134.205: hdmi: HDMI:EDID error reading EDID block 0 attempt 0
001135.466: hdmi: HDMI:EDID error reading EDID block 0 attempt 1
001136.727: hdmi: HDMI:EDID error reading EDID block 0 attempt 2
001137.988: hdmi: HDMI:EDID error reading EDID block 0 attempt 3
001139.249: hdmi: HDMI:EDID error reading EDID block 0 attempt 4
001140.510: hdmi: HDMI:EDID error reading EDID block 0 attempt 5
001141.771: hdmi: HDMI:EDID error reading EDID block 0 attempt 6
001143.032: hdmi: HDMI:EDID error reading EDID block 0 attempt 7
001144.293: hdmi: HDMI:EDID error reading EDID block 0 attempt 8
001145.554: hdmi: HDMI:EDID error reading EDID block 0 attempt 9
001146.578: hdmi: HDMI:EDID giving up on reading EDID block 0
001146.643: hdmi: HDMI: hotplug deassert
001146.658: hdmi: HDMI: HDMI is currently off
001146.672: hdmi: HDMI: changing mode to unplugged
001146.694: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state                                                                                         instead
001147.475: *** Restart logging
001148.429: Read command line from file 'cmdline.txt'
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=d                                                                                        eadline fsck.repair=yes rootwait
001149.206: Loading 'kernel.img' from SD card
001389.282: Kernel trailer DTOK property says yes
001389.378: Loading 'bcm2708-rpi-b.dtb' from SD card
001433.252: Loaded overlay 'w1-gpio'
001433.343: dtparam: spi=off
001436.617: dtparam: i2c_arm=off
001453.269: dtparam: arm_freq=700000000
001454.497: Unknown dtparam 'arm_freq' - ignored
001454.534: dtparam: core_freq=250000000
001458.959: dtparam: uart1_clkrate=500000000
001460.189: Unknown dtparam 'uart1_clkrate' - ignored
001460.207: dtparam: cache_line_size=32
001493.081: gpioman: gpioman_get_pin_num: pin SDCARD_CONTROL_POWER not defined
002439.176: vchiq_core: vchiq_init_state: slot_zero = 0x4bc80000, is_master = 1
002443.373: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state                                                                                         instead
002448.004: gpioman: gpioman_get_pin_num: pin LEDS_RUNNING not defined
002448.031: gpioman: gpioman_get_pin_num: pin LEDS_NAND_ACTIVITY not defined
002448.056: gpioman: gpioman_get_pin_num: pin LEDS_USB_ACTIVITY not defined
002448.079: gpioman: gpioman_get_pin_num: pin LEDS_FATAL_ERROR not defined
002448.100: gpioman: gpioman_get_pin_num: pin LEDS_APP_OK not defined
002448.120: gpioman: gpioman_get_pin_num: pin LEDS_APP_FAILED not defined
002448.142: gpioman: gpioman_get_pin_num: pin LEDS_HDCP_AUTH not defined
002448.163: gpioman: gpioman_get_pin_num: pin LEDS_HDCP_UNAUTH not defined
002448.184: gpioman: gpioman_get_pin_num: pin LEDS_HDMI_ON not defined
002448.204: gpioman: gpioman_get_pin_num: pin LEDS_DVI_ON not defined
002448.225: gpioman: gpioman_get_pin_num: pin LEDS_HDMI_HPD_UP not defined
002448.248: gpioman: gpioman_get_pin_num: pin LEDS_REMOTE_CONTROL not defined
002448.271: gpioman: gpioman_get_pin_num: pin LEDS_ARM_CONTROLLED not defined
Please help!!!

gpio read 1I get 1 when wired and 0 when not). – benbbh Nov 26 '15 at 20:21