Bug not fixed - Temperature below 0 deg C - shows as 4M Celcius

Help
1

So last Feburary I added the DS18b20 external sensor to three of my Raspberry Pies to monitior temps around the house etc. One of the sensors are in the loft area of the house and thus are exposed to outside temps. Today was the first day with around -8c here in my area. And now my Librenms is reporting 4.4 million Celcius and wrecked the rrd graphs. Since I am work right now I cannot post to much info as I cannot access the rpi’s remotely.

Anywas this issue was escalated to Net-snmp - but here we are again 10 months later with the same issue.

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2

We graph the data sent to us but without poller debug info we can’t really do much

3

Yeah sure, as soon as I can. But in the meantime…

4

Okay here we go:

hostname:  192.168.1.50  (unix)
ID:        6
OS:        linux
IP:        192.168.1.50
  
#### Load poller module core ####
  
Uptime: 1 week 1 day 22 hours 9 minutes 52 seconds  
  
>> SNMP: [3/0.12s] MySQL: [4/0.10s] RRD: [2/0.00s]  
>> Runtime for poller module 'core': 0.0953 seconds with 164056 bytes  
#### Unload poller module core ####
  
#### Load poller module os ####
  
Location: Oslo,Norway  
Hardware: Generic ARMv8 64-bit  
OS Version: 6.1.21-v8+  
OS Features:   
Serial:   
  
>> SNMP: [0/0.00s] MySQL: [1/0.01s] RRD: [1/0.00s]  
>> Runtime for poller module 'os': 0.0111 seconds with 101752 bytes  
#### Unload poller module os ####
  
#### Load poller module availability ####
  
1 day   : 100%  
1 week  : 100%  
1 month : 99.977%  
1 year  : 99.981%  
  
>> SNMP: [0/0.00s] MySQL: [13/0.18s] RRD: [5/0.00s]  
>> Runtime for poller module 'availability': 0.0429 seconds with 55416 bytes  
#### Unload poller module availability ####
  
#### Load poller module sensors ####
  
Checking (snmp) temperature temp1... 
Checking (snmp) temperature w1_slave_temp-virtual-0:temp1... 
31.154 C
4294966.421 C
  
>> SNMP: [1/0.83s] MySQL: [4/0.11s] RRD: [3/0.00s]  
>> Runtime for poller module 'sensors': 0.8416 seconds with 5072 bytes  
#### Unload poller module sensors ####
  
#### Load poller module processors ####
  
Processor: 32%
Processor: 34%
Processor: 26%
Processor: 17%
  
>> SNMP: [1/0.03s] MySQL: [5/0.14s] RRD: [5/0.00s]  
>> Runtime for poller module 'processors': 0.0525 seconds with 58552 bytes  
#### Unload poller module processors ####
  
#### Load poller module mempools ####
  
hrstorage [system]: Physical memory: 17%  656.66 MiB / 3.71 GiB  
hrstorage [virtual]: Virtual memory: 60%  2.28 GiB / 3.8 GiB  
hrstorage [buffers]: Memory buffers: 3%  103.64 MiB / 3.71 GiB  
hrstorage [cached]: Cached memory: 41%  1.53 GiB / 3.71 GiB  
hrstorage [shared]: Shared memory: 1%  51.41 MiB / 3.71 GiB  
hrstorage [swap]: Swap space: 0%  0 B / 100 MiB  
  
>> SNMP: [1/0.03s] MySQL: [6/0.19s] RRD: [7/0.00s]  
>> Runtime for poller module 'mempools': 0.0703 seconds with 92672 bytes  
#### Unload poller module mempools ####
  
#### Load poller module storage ####
  
Storage /: hrstorage



65% 
  
>> SNMP: [1/0.09s] MySQL: [2/0.05s] RRD: [2/0.00s]  
>> Runtime for poller module 'storage': 0.1011 seconds with 8192 bytes  
#### Unload poller module storage ####
  
#### Load poller module netstats ####
  
icmp   
ip   
ip_forward   
snmp   
udp   
tcp   
  
>> SNMP: [8/0.32s] MySQL: [0/0.00s] RRD: [6/0.00s]  
>> Runtime for poller module 'netstats': 0.3368 seconds with 24872 bytes  
#### Unload poller module netstats ####
  
#### Load poller module hr-mib ####
  
 Processes Users
  
>> SNMP: [1/0.05s] MySQL: [2/0.05s] RRD: [3/0.00s]  
>> Runtime for poller module 'hr-mib': 0.0660 seconds with 24216 bytes  
#### Unload poller module hr-mib ####
  
#### Load poller module ucd-mib ####
  
  
>> SNMP: [2/0.06s] MySQL: [0/0.00s] RRD: [19/0.01s]  
>> Runtime for poller module 'ucd-mib': 0.0742 seconds with 8520 bytes  
#### Unload poller module ucd-mib ####
  
#### Load poller module ipSystemStats ####
  
ipv4 ipv6 
  
>> SNMP: [1/0.04s] MySQL: [0/0.00s] RRD: [3/0.00s]  
>> Runtime for poller module 'ipSystemStats': 0.0496 seconds with 3280 bytes  
#### Unload poller module ipSystemStats ####
  
#### Load poller module ports ####
  
Caching Oids: Full ports polling ifDescr ifAdminStatus ifOperStatus ifLastChange ifType ifPhysAddress ifMtu ifInErrors ifOutErrors ifInDiscards ifOutDiscards dot3StatsDuplexStatus
Port lo: lo (1 / #24) disabled.
Port eth0: eth0 (2 / #27) dot3Duplex VLAN = ? eth0bps(0 bps/12.52 Mbps)bytes(0 B/101.48 MiB)pkts(1.5 kpps/1.54 kpps)
Port wlan0: Device 02d0:a9a6 (3 / #30) disabled.
  
>> SNMP: [14/0.47s] MySQL: [4/0.11s] RRD: [2/0.00s]  
>> Runtime for poller module 'ports': 0.5112 seconds with 50032 bytes  
#### Unload poller module ports ####
  
#### Load poller module customoid ####
  
  
>> SNMP: [0/0.00s] MySQL: [1/0.02s] RRD: [1/0.00s]  
>> Runtime for poller module 'customoid': 0.0060 seconds with 2512 bytes  
#### Unload poller module customoid ####
  
#### Load poller module ucd-diskio ####
  
mmcblk0 mmcblk0p1 mmcblk0p2 
  
>> SNMP: [1/0.04s] MySQL: [1/0.01s] RRD: [4/0.00s]  
>> Runtime for poller module 'ucd-diskio': 0.0540 seconds with 13168 bytes  
#### Unload poller module ucd-diskio ####
  
#### Load poller module entity-physical ####
  
  
>> SNMP: [0/0.00s] MySQL: [0/0.00s] RRD: [1/0.00s]  
>> Runtime for poller module 'entity-physical': 0.0029 seconds with 6832 bytes  
#### Unload poller module entity-physical ####
  
#### Load poller module applications ####
  
Application: portactivity, app_id=14: ..........................................

  
>> SNMP: [1/0.11s] MySQL: [4/0.09s] RRD: [2/0.00s]  
>> Runtime for poller module 'applications': 0.1264 seconds with 146624 bytes  
#### Unload poller module applications ####
  
#### Load poller module ntp ####
  
  
>> SNMP: [0/0.00s] MySQL: [0/0.00s] RRD: [1/0.00s]  
>> Runtime for poller module 'ntp': 0.0018 seconds with 1768 bytes  
#### Unload poller module ntp ####
  
Enabled graphs (27): poller_perf ping_perf poller_modules_perf uptime availability netstat_icmp netstat_icmp_info netstat_ip netstat_ip_frag netstat_snmp netstat_snmp_pkt netstat_udp netstat_tcp hr_processes hr_users ucd_cpu ucd_swap_io ucd_io ucd_contexts ucd_interrupts ucd_io_wait ucd_cpu_steal ucd_load ipsystemstats_ipv4 ipsystemstats_ipv4_frag ipsystemstats_ipv6 ipsystemstats_ipv6_frag

  

>>> Polled nms.gwdebian.net (6) in 3.605 seconds <<<  
#### Start Alerts ####  
Rule #3 (Syslog, Authentication failure on Device):   
Status: NOCHG  
Rule #4 (Space on / is >= 90%and < 95%in use):   
Status: NOCHG  
#### End Alerts (0.0408s) ####
  
### Start Device Groups ###  
### End Device Groups (0.0113s) ### 
  
SNMP [35/2.19s]: Snmpget[17/1.51s] Snmpwalk[18/0.68s]  
SQL [66/1.39s]: Select[41/0.67s] Update[24/0.71s] Delete[1/0.01s]  
RRD [69/0.04s]: Update[69/0.04s]

and the output of a python script quering the same sensor:

pi@librenms:~ $ python tempsensor.py 
22/11/24@07:54:14 - -1.0 C
22/11/24@07:54:17 - -0.9 C
22/11/24@07:54:20 - -0.9 C
22/11/24@07:54:23 - -1.0 C
22/11/24@07:54:26 - -1.0 C

And the source of said script:

#!/usr/bin/env python

import os
import glob
import time
import datetime

def read_temp(decimals = 1, sleeptime = 3):

    """Reads the temperature from a 1-wire device"""

    device = glob.glob("/sys/bus/w1/devices/" + "28*")[0] + "/w1_slave"
    while True:
        try:
            timepoint = datetime.datetime.now()
            with open(device, "r") as f:
                lines = f.readlines()
            while lines[0].strip()[-3:] != "YES":
                time.sleep(0.2)
                lines = read_temp_raw()
            timepassed = (datetime.datetime.now() - timepoint).total_seconds()
            equals_pos = lines[1].find("t=")
            if equals_pos != -1:
                temp_string = lines[1][equals_pos+2:]
                temp = round(float(temp_string) / 1000.0, decimals)
                print(time.strftime("%d/%m/%y@%H:%M:%S - ")+str(temp)+" C")
                time.sleep(sleeptime-timepassed)
                timepoint = datetime.datetime.now()
        except KeyboardInterrupt:
            break

if __name__ == "__main__":
    read_temp()

The script has nothing to do with LibreNMS - just providing data before I hit the sack!

And about Librenms:

|Version |24.11.0 - Thu Nov 21 2024 00:15:08 GMT+0100|
|---|---|
|Database Schema |2024_10_13_162920_add_custom_map_nodeimage_column (307)|
|Web Server |Apache/2.4.62 (Raspbian)|
|PHP |8.3.10|
|Python |3.9.2|
|Database |MariaDB 10.5.26-MariaDB-0+deb11u2|
|Laravel |10.48.23|
|RRDtool |1.7.2|