In 2008 I tried som PIC16F assembler to read the DS18S20 temperature chip.
http://www.dougrice.plus.com/dev/sl004ds1820.asm
and using the program memory of the PIC16F88
http://www.dougrice.plus.com/dev/logger88/sl004ds1820.asm
I had brought one of these kits. https://quasarelectronics.co.uk/Item/3145-ds18s20-computer-serial-temperature-data-logger
It needs a computer with a serial port logging the output. I turn off my laptops and desktops.
Now the Raspberry Pi can be left powered up, and now I know how to use "crontab -e", or /etc/rc.local to start my logging script on reboot.
The Raspberry Pi One Wire interface simplifies reading a collections of DS18S20 or DS18B20.
http://www.dougrice.plus.com/dev/logger88/DS18S20.pdf - datasheet for Dallas DS18S20
I wrote a webpage about the crc calculation
http://www.dougrice.plus.com/dev/crc.htm
Early in 2026, I brought some little boards with the DS18B20 chips to measure temperature. They came with ESP01S
The ESP01S is just under the ESP01S and the little blue board provides a voltage regulator.
The DS18B20 is connected to IO 2
I can power the blue board with a USB cable plugged into a mains adaptor with a 5V USB-A socket.
I used an IR Infrared Thermometer to measure the temperature of the ESP01 and the board.
The ESP01S gets quite warm at about 30 degree C
If you leave the ESP01 unplugged, and power up the blue board, it seems to be a 1 degree hotter than the red card.
I brought some waterproof DS18B20 with 1m of cable, which could be soldered onto the back of the blue board. This seems to be reading a realistic temperature.
http://www.dougrice.plus.com/dev/tcpip/IOT/mainDS18B20used.py is a later version that works enough.
http://www.dougrice.plus.com/dev/tcpip/IOT/mainDS18B20_2.py is a mash up from the links below.
https://docs.micropython.org/en/latest/esp8266/tutorial/onewire.html has an example.
Sometimes you need to upload Micro-Python to the ESP01 board.
I had to use the 1MB version: ESP8266_GENERIC-FLASH_1M-20251209-v1.27.0.bin
I found this at found on https://micropython.org/download/ESP8266_GENERIC/
I used the D1 board to tinker with the micropython example. I had to select 4MB when uploading the MicroPython?
This page records some work on using DS18S20 with Raspberry Pi and plotting using AWK, SVG and JavaScript?.
Using the kernal extensions ( see links ) the Raspberry Pi can use the "one wire" interface to read the Dallas 18S20 temperature chips.
I use a shell script to poll the chips and append the readings to a file of JavaScript? function calls and other text files.
An awk script is used to extract the text and populate the gbF() function calls. If written to a file, the file can be included into an SVG file.
Using JavaScript? in an SVG file, I plot the data as a simple graph. The SVG file does a location.reload() to update.
This is run in the Midori 0.4.3 web browser that renders the SVG file.
example: http://www.dougrice.plus.com/raspberryPi_ds1820/loopDS18S20reportSVG.svg
files: http://www.dougrice.plus.com/raspberryPi_ds1820/
enable One wire using /bin/raspi-config
The Raspberry Pi can read the DS18B20 using the One-wire. Example:
pi@rpiw:~ $ cat /sys/bus/w1/devices/10-*/w1* 24 00 4b 46 ff ff 10 10 0d : crc=0d YES 24 00 4b 46 ff ff 10 10 0d t=17750 pi@rpiw:~ $ cat /sys/bus/w1/devices/10-*/w1* 24 00 4b 46 ff ff 10 10 0d : crc=0d YES 24 00 4b 46 ff ff 10 10 0d t=17750
To run every 15 minutes add this to a cron job
crontab -e
#Add this # # m h dom mon dow command # poll DS18S20.sh using one wire 0,15,30,45 * * * * /usr/bin/bash /home/pi/log18S20.sh
Edit log18S20.sh bash script that is run every 15 minutes.
cd ~ nano log18S20.sh
#! /bin/bash
# log18S20.sh
#
echo "===" >> /home/pi/log18S20.txt
date -u +'%Y-%m-%d %H:%M' >> /home/pi/log18S20.txt
# only log the temperature t=
cat /sys/bus/w1/devices/10-*/w1* | awk '/t=/ { print $10 }' >> /home/pi/log18S20.txt
Login and cat /home/pi/log18S20_rpiw.txt
I set the hostname of the Raspberry Pi Zero W to rpiw
Use SCP to fetch the file of temperatures
scp pi@rpiw://home/pi/log18S20.txt log18S20_rpiw.txt
E.G log18S20_rpiw.txt contains:-
=== 2025-03-14 21:45 === 2025-03-14 22:00 t=20187 === 2025-03-14 22:15 t=20125 === 2025-03-14 22:30 t=20062
An example using a Raspberry Pi Zero and DS18S20 in one room and another Raspberry Pi and another DS18S20 in another room.
These Raspberry Pi are on my local lan and only accessable from a computer on the same lan.
Every 15 minutes each Pi take a measurement and append to a file which can be included in a web page.
gbFa( "2025-03-19 07:00 t=12375" ) gbFa( "2025-03-19 07:15 t=12500" ) gbFa( "2025-03-19 07:30 t=12625" )
This web page includes the data files from each pi and plots the data:-
src="http://rpiw/gb/gbFa.js" , copy in gbFar.js
src="http://patrickpi:8086/gb/gbFa.js" , copy in gbFap.js
http://www.dougrice.plus.com/dev/graphs/graphPi.htm - This Webpage includes the data and uses JavaScript? to plot on the <CANVAS> on the web page.
This depends on the Raspberry Pi time and date being the same.
do_dates.bat can be used to check the clocks of the web servers I am interested in. Win 11 seems to have curl
rem rem rem echo "do.bat " >temp.txt type do_dates.bat date /T >> temp.txt time /T >> temp.txt curl -s --head http://patrickpi >> temp.txt curl -s --head http://rpiw >> temp.txt curl -s --head http://192.168.1.254 >> temp.txt curl -s --head http://dougrice.co.uk >> temp.txt curl -s --head http://www.bbc.co.uk >> temp.txt curl -s --head http://ccgi.dougrice.plus.com >> temp.txt curl -s --head http://www.dougrice.plus.com >> temp.txt
curl -s --head http://192.168.1.63 >> temp.txt
type temp.txt | find "Date" dir temp.txt time /T
http://www.dougrice.plus.com/raspberryPi_ds1820/tt.awk
One wire - DS18S20 reader
Used GPIO4 pin 7 - middle pin. 3v3 to power gnd to gnd
/ 3v3 DS18S20 - top (|- buss --GPIO4--[4k7]--/ \ gnd
Web pages to help:-
http://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing/hardware
http://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing/ds18b20
The script below starts the kernel module for "OneWire?" and loops polling all the devices onthe Bus.
I have 4 DS18S20, which I read and set userfield1,userfield2,userfield3,userfield4 parameters in gbF() guestbook Function. This is appended to gbookFtemp.js on the desk top. The date is set to when I read the devices.
#! /bin/bash # # Shell Script to poll temperature chips # usage: bash loop.sh # # http://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing/hardware # echo "---------------------" ls /sys/bus echo "---------------------" sudo modprobe w1-gpio sudo modprobe w1-therm echo "---------------------" ls /sys/bus echo "---------------------" while [[ 1 ]] do echo "========" > ~/Desktop/tmp.txt date >> ~/Desktop/tmp.txt cat /sys/bus/w1/devices/10-*/name >> ~/Desktop/tmp.txt cat /sys/bus/w1/devices/10-*/w1* >> ~/Desktop/tmp.txt echo " " >> ~/Desktop/tmp.txt # # use AWK to extract the temperatures. appends gbF() to gbookFtemp.js # cat ~/Desktop/tmp.txt awk -f loop.awk ~/Desktop/tmp.txt cat ~/Desktop/tmp.txt >> ~/Desktop/loop_log.txt sleep 3 done
This awk script extracts the temperature and puts the results into the javascript include file.
#
#
# loop.awk
#
# usage: awk -f loop.awk loop_log.txt
#
#
# pull out the temperature from loop_log.txt written by loop.sh
# Appends to "gbookFtemp.js"
#
#
#//gbF( name,email,postedOn,IPaddress,userfield1,userfield2,userfield3,userfield4,comments){
BEGIN {
FS="="
# zero the temperatures
ln[1]=0
ln[2]=0
ln[3]=0
ln[4]=0
# print "" > "gbookFtemp.js"
notFirst = 0
}
/====/{
print $0
getline
print $0
lnp=1
cnt +=1
if ( notFirst ){
print "gbF( 'awk','t@pi','" lastDate " ','127.0.0.1'," ln[1] "," ln[2] "," ln[3] "," ln[4] ",'comments');" >> "gbookFtemp.js"
}
# prepare for next readings
notFirst = 1
ln[1]=0
ln[2]=0
ln[3]=0
ln[4]=0
lastDate = $0
}
/t=/{
# found a line with a temperature
ln[lnp] = ($NF/1000)
lnp ++
}
END {
cnt +=1
print "gbF( 'awk','t@pi','" lastDate " ','127.0.0.1'," ln[1] "," ln[2] "," ln[3] "," ln[4] ",'comments');" >> "gbookFtemp.js"
}
gbF( 'awk','t@pi','Sun Feb 9 10:30:47 UTC 2014 ','127.0.0.1',17.375,18,17.5,17.312,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:30:53 UTC 2014 ','127.0.0.1',17.312,18,17.5,17.312,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:00 UTC 2014 ','127.0.0.1',17.375,19.187,17.562,17.375,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:06 UTC 2014 ','127.0.0.1',17.375,19.187,17.562,17.437,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:13 UTC 2014 ','127.0.0.1',17.437,23.25,17.562,17.5,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:20 UTC 2014 ','127.0.0.1',17.437,24.375,17.625,17.562,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:27 UTC 2014 ','127.0.0.1',17.5,25.375,17.687,17.562,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:33 UTC 2014 ','127.0.0.1',17.5,26.062,17.687,17.562,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:40 UTC 2014 ','127.0.0.1',17.5,26.687,17.687,17.625,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:46 UTC 2014 ','127.0.0.1',17.562,27.562,17.75,17.625,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:53 UTC 2014 ','127.0.0.1',17.562,28.437,17.75,17.687,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:31:59 UTC 2014 ','127.0.0.1',17.625,28.937,17.75,17.687,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:32:06 UTC 2014 ','127.0.0.1',17.625,-1.25,17.812,17.687,'comments'); gbF( 'awk','t@pi','Sun Feb 9 10:32:13 UTC 2014 ','127.0.0.1',17.625,29.5,17.812,17.687,'comments');
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" width="600" height="600" >
<script type="text/ecmascript"><![CDATA[
//
// Include javascript guestbook and process it. Plots Temperature measurements from DS18S20.
//
var count=1
var opStr = ""
var linePointsStr2 = ""
var linePointsStr3 = ""
var linePointsStr4 = ""
var linePointsStr5 = ""
var xIndex = 50
var tempStr =""
//
// This function is called once per guestbook entry stored in gbookFtemp.js
// There is a lot of junk in there, which needs to be ignored.
//
function gbF( name,email,postedOn,IPaddress,userfield1,userfield2,userfield3,userfield4,comments){
// var yvalue = 200 + Math.random()*32
scale = 10.0
var yvalue = userfield1*1.0
if ( yvalue != -1.25) { linePointsStr2 += xIndex + "," + ( 400 - yvalue*scale ) + " " }
var yvalue = userfield2*1.0
if ( yvalue != -1.25) { linePointsStr3 += xIndex + "," + ( 400 - yvalue*scale ) + " " }
var yvalue = userfield3*1.0
if ( yvalue != -1.25) { linePointsStr4 += xIndex + "," + ( 400 - yvalue*scale ) + " " }
var yvalue = userfield4*1.0
if ( yvalue != -1.25) { linePointsStr5 += xIndex + "," + ( 400 - yvalue*scale ) + " " }
xIndex += 1
tempStr = "last temperatures: " +userfield1 +","+userfield2+","+userfield3+","+userfield4
}
function plotMeasured() {
//
// Guestbox processed
//
obj2=document.getElementById("dhr2");
obj2.setAttributeNS(null,"points", linePointsStr2 );
obj3=document.getElementById("dhr3");
obj3.setAttributeNS(null,"points", linePointsStr3 );
obj4=document.getElementById("dhr4");
obj4.setAttributeNS(null,"points", linePointsStr4 );
obj5=document.getElementById("dhr5");
obj5.setAttributeNS(null,"points", linePointsStr5 );
}
]]></script>
// window
<defs>
<!-- Set up clip path to constrain graphs to plot window -->
<clipPath id = "clip1">
<path d = "M 48 53 L 548 53 L 548 420 L 48 420 L 48 53 "/>
</clipPath>
<radialGradient id = "g1" cx = "50%" cy = "50%" r = "50%" fx = "25%" fy = "25%">
<stop stop-color = "#ffff66" offset = "0%"/>
<stop stop-color = "#FFFFCC" offset = "50%"/>
<stop stop-color = "white" offset = "100%"/>
</radialGradient>
<linearGradient id = "g2" x1 = "10%" y1 = "10%" x2 = "90%" y2 = "90%">
<stop stop-color = "white" offset = "0%"/>
<stop stop-color = "#7fff66" offset = "25%"/>
<stop stop-color = "white" offset = "100%"/>
</linearGradient>
</defs>
// outer square
<rect x="0" y="0" width="600" height="590" fill = "url(#g2)" />
//
// plot canvas
//
<rect x="48" y="53" width="500" height="500" stroke="blue" fill = "url(#g1)" />
//
// define 4 polylines. javascript will change points later.
//
<polyline id="dhr2" fill="none" stroke="blue" stroke-width="2" points="" clip-path = "url(#clip1)" />
<polyline id="dhr3" fill="none" stroke="lime" stroke-width="2" points="" clip-path = "url(#clip1)" />
<polyline id="dhr4" fill="none" stroke="red" stroke-width="2" points="" clip-path = "url(#clip1)" />
<polyline id="dhr5" fill="none" stroke="orange" stroke-width="2" points="" clip-path = "url(#clip1)" />
//
// minor axis lines
//
<line x1="52" y1="100" x2="545" y2="100" style="stroke:rgb(99,99,99);stroke-width:1" />
<line x1="52" y1="200" x2="545" y2="200" style="stroke:rgb(99,99,99);stroke-width:1" />
<line x1="52" y1="300" x2="545" y2="300" style="stroke:rgb(99,99,99);stroke-width:1" />
<line x1="52" y1="400" x2="545" y2="400" style="stroke:rgb(10,10,10);stroke-width:2" />
<line x1="52" y1="500" x2="545" y2="500" style="stroke:rgb(99,99,99);stroke-width:1" />
<text x="260" y="20" text-anchor="middle" font-family="Arial,Helvetica" font-size="14px" font-weight="bold" >Temperature Plot using SVG, run: bash loop.sh</text>
<text x="260" y="40" text-anchor="middle" font-family="Arial,Helvetica" font-size="14px" id="svg_21" >data from gbookFtemp.js - DS18S20</text>
<text x="260" y="580" text-anchor="middle" font-family="Arial,Helvetica" font-size="14px" font-weight="bold" >measurement</text>
<text transform="rotate(270,20,300)" x="20" y="300" font-family="Arial,Helvetica" text-anchor="middle" font-size="14px" pointer-events="none" font-weight="bold" >Temperature Centigrade</text>
<text x="30" y="500" text-anchor="middle" font-family="Arial,Helvetica" font-size="8px" >-10 C </text>
<text x="30" y="400" text-anchor="middle" font-family="Arial,Helvetica" font-size="8px" >0 C </text>
<text x="30" y="300" text-anchor="middle" font-family="Arial,Helvetica" font-size="8px" >10 C </text>
<text x="30" y="200" text-anchor="middle" font-family="Arial,Helvetica" font-size="8px" >20 C </text>
<text x="30" y="100" text-anchor="middle" font-family="Arial,Helvetica" font-size="8px" >30 C </text>
<script type="text/ecmascript" xlink:href="gbookFtemp.js" />
//
// include data from guestbook and process.
//
//
// update polyline points
//
<script type="text/ecmascript"><![CDATA[
obj6=document.getElementById("svg_21");
obj6.textContent = tempStr
plotMeasured()
window.setInterval("location.reload();",6000);
]]></script>
</svg>
ebay suggested the ESP01 and support to reprogram these has been added to the Arduino.
Another way to upload code onto them is to use MicroPython? and the Thonny Python IDE shipped with the Raspberry Pi.
https://micropython.org/download/esp8266/ - there are plenty of examples which can be uploaded using Thonny at the touch of the GO button.
I brought some little boards with the DS18B20 chips to measure temperature. They came with ESP01S
The DS18B20 is connected to IO 2
I can power the blue board with a USB cable plugged into a mains adaptor with a 5V USB-A socket.
I used an IR Infrared Thermometer to measure the temperature of the ESP01 and the board.
The ESP01S gets quite warm at about 30 degree C
If you leave the ESP01 unplugged, and power up the blue board, it seems to be a 1 degree hotter than the red card.
I brought some waterproof DS18B20 with 1m of cable, which could be soldered onto the back of the blue board. This seems to be reading a realistic temperature.
They are reading about 8 to 10 degrees less.
http://www.dougrice.plus.com/dev/tcpip/IOT/mainDS18B20used.py is a later version that works enough.
This Thonny sketch allows me to poll the temperature using a web server.
http://www.dougrice.plus.com/dev/tcpip/IOT/mainDS18B20_2.py
I can poll this with a cron job and use curl and grep out what I want. The time stamp comes from the Raspberry Pi Zero.
===
2026-02-13 21:30
<h2> 2 , DS18B20 , 5.0 , 15.125 , [, 0x28,0xe8,0x42,0xc0,0x0,0x0,0x0,0xc5, ] , [, 0x28,0x20,0x4d,0xbc,0x0,0x0,0x0,0x2e, ] , </h2>
It might be better to use a client that deep sleeps the ESP01, wakes up takes the measurement, sends it to a server and deep sleeps.
http://www.dougrice.plus.com/dev/tcpip/IOT/mainDS18B20used.py is a later version that works enough.
http://www.dougrice.plus.com/dev/tcpip/IOT/mainDS18B20_2.py is a mash up from the links below.
https://docs.micropython.org/en/latest/esp8266/tutorial/onewire.html has an example.
Open Thonny and type help() and it has example code for connecting the ESP01 to the WiFi?.
https://docs.micropython.org/en/latest/esp8266/tutorial/network_tcp.html has some code for a web server.
Thonny would not let me save main.py to the ESP-01S until I flashed it with the 1MB vesion.
I needed to use the 1MB bin so I could save main.py
ESP8266_GENERIC-FLASH_1M-20251209-v1.27.0.bin found on https://micropython.org/download/ESP8266_GENERIC/
I brought a board ESP8266-D1-WeMos?-D1. This simplifies developing the code for the ESP01
