I have read a few posts here on my issue, notably DS18B20 not detected by Raspberry Pi, but unfortunately none of the suggestions worked for my issue. I am seeking advice on additional troubleshooting measures that I can undertake.
I have used DS18B20 sensors for several years with Arduino & RPi boards. In one particular arrangement, I didn't pay attention to the data since I had a DHT11 and a BME680 to corroborate the readings. Unfortunately, I have a monthly SQL TRUNCATE table operation and I cannot provide a specific date when the DS18B20 (or RPi OS) stopped creating the corresponding folder in /sys/bus/w1/devices owing regularly scheduled unattended update/upgrade operations in my farm. These sensors (I have a dozen+ of these) work presently in Arduino boards without issues. The failures occur with RPi0W and RPi3B boards.
The corresponding /boot/config.txt file has the following entry:
I've used modprobe as follows:
$ sudo modprobe w1_gpio $ sudo modprobe w1_therm
I've confirmed that the corresponding processes are active by using the following command:
$ lsmod | grep w1 w1_therm 24576 0 w1_gpio 16384 0 wire 40960 2 w1_gpio,w1_therm $
When I explore /sys/bus/w1/devices, I do not find the folders with the 28- prefix for each DS18B20 sensor in the setup. I sometimes use multiple DS18B20 sensors in parallel and naturally when the solution was working each sensor had its unique 28- folder. The sensors are not in parasitic operation and there is a 4.7K resistor between data and 3.3VDC pins for the sensors. (Just to reiterate with due apologies for restating, the sensors were working previously on the same boards and are currently working with several different Arduino boards).
The RPi3 board is as follows:
$ uname -a Linux raspbari9 5.4.70-v7+ #1348 SMP Wed Oct 7 16:14:38 BST 2020 armv7l GNU/Linux $
I noticed that others had provided some boot messages. Here is one sample from my RPi3 board:
$ sudo vcdbg log msg 001530.977: brfs: File read: /mfs/sd/config.txt 001532.132: brfs: File read: 1823 bytes 001581.356: HDMI:EDID error reading EDID block 0 attempt 0 001582.618: HDMI:EDID error reading EDID block 0 attempt 1 001583.878: HDMI:EDID error reading EDID block 0 attempt 2 001585.139: HDMI:EDID error reading EDID block 0 attempt 3 001586.399: HDMI:EDID error reading EDID block 0 attempt 4 001587.660: HDMI:EDID error reading EDID block 0 attempt 5 001588.919: HDMI:EDID error reading EDID block 0 attempt 6 001590.180: HDMI:EDID error reading EDID block 0 attempt 7 001591.440: HDMI:EDID error reading EDID block 0 attempt 8 001592.700: HDMI:EDID error reading EDID block 0 attempt 9 001593.718: HDMI:EDID giving up on reading EDID block 0 001596.151: brfs: File read: /mfs/sd/config.txt 001597.199: gpioman: gpioman_get_pin_num: pin LEDS_PWR_OK not defined 001615.644: brfs: File read: 1823 bytes 001620.795: gpioman: gpioman_get_pin_num: pin WL_LPO_CLK not defined 001620.819: gpioman: gpioman_get_pin_num: pin BT_ON not defined 001620.838: gpioman: gpioman_get_pin_num: pin WL_ON not defined 001795.608: gpioman: gpioman_get_pin_num: pin DISPLAY_DSI_PORT not defined 001796.854: gpioman: gpioman_get_pin_num: pin LEDS_PWR_OK not defined 001796.918: *** Restart logging ... <N.B. removed several lines related to HDMI messages; I used headless mode of operation> 001833.789: dtb_file 'bcm2709-rpi-2-b.dtb' 001838.362: brfs: File read: /mfs/sd/bcm2709-rpi-2-b.dtb 001838.386: Loading 'bcm2709-rpi-2-b.dtb' to 0x100 size 0x66dd 001851.027: brfs: File read: 26333 bytes 001869.401: brfs: File read: /mfs/sd/overlays/overlay_map.dtb 001938.351: brfs: File read: 1463 bytes 001942.056: brfs: File read: /mfs/sd/config.txt 001942.603: dtparam: i2c_arm=on 001950.328: dtparam: spi=on 001957.160: dtparam: audio=on 001967.404: brfs: File read: 1823 bytes 001990.603: brfs: File read: /mfs/sd/overlays/w1-gpio-pullup.dtbo 001996.328: Loaded overlay 'w1-gpio-pullup' 001996.345: dtparam: gpiopin=4 001997.649: dtparam: pullup=1 002024.368: brfs: File read: 1171 bytes 002027.223: brfs: File read: /mfs/sd/cmdline.txt 002027.283: Read command line from file 'cmdline.txt': 002027.307: 'console=serial0,115200 console=tty1 root=PARTUUID=5e3da3da-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles' 003961.076: gpioman: gpioman_get_pin_num: pin EMMC_ENABLE not defined 004007.597: gpioman: gpioman_get_pin_num: pin WL_ON not defined 004011.483: brfs: File read: 166 bytes 004414.835: brfs: File read: /mfs/sd/kernel7.img 004414.859: Loading 'kernel7.img' to 0x8000 size 0x581110 004414.891: Device tree loaded to 0x2eff9400 (size 0x6be9) 004420.495: gpioman: gpioman_get_pin_num: pin SDCARD_CONTROL_POWER not defined 007492.364: vchiq_core: vchiq_init_state: slot_zero = 0xf7580000, is_master = 1 007496.776: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state instead 007502.305: TV service:host side not connected, dropping notification 0x00000002, 0x00000002, 0x00000023 $
Obviously, this is some self-inflicted operator/user error. All suggestions are welcome since I would like to get more usage out of the many DS18B20 sensors that I have. Many thanks.