Extending DS18(B)20 driver - multiple GPIOs and multiple sensors per GPIO

max4elektroda 2433 108

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#91 21622509 31 Jul 2025 19:55

max4elektroda max4elektroda

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Post #91
21622509 31 Jul 2025 19:55

Your logs/tests look good, so why not!
Thanks for testing again

Added after 14 [minutes]:

Compiled this time
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#92 21622568 31 Jul 2025 20:44

divadiow divadiow

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Post #92
21622568 31 Jul 2025 20:44

Code: Text
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Attachments:

ds1820_bk7252u68_p24_1727_merge_243359742dca.zip Download (2.09 KB)
#93 21622576 31 Jul 2025 20:51

divadiow divadiow

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Post #93
21622576 31 Jul 2025 20:51
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#94 21622586 31 Jul 2025 20:59

max4elektroda max4elektroda

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Post #94
21622586 31 Jul 2025 20:59

Wow, looks quite good, only 20us is a bit short with 16us in real:

500 479
200 193
100 97
50 49
20 16
10 9
6 6
4 4

Thank you so much!
#95 21622588 31 Jul 2025 21:00

divadiow divadiow

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Post #95
21622588 31 Jul 2025 21:00

no, thank you!

good stuff
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#96 21622795 01 Aug 2025 06:35

max4elektroda max4elektroda

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Post #96
21622795 01 Aug 2025 06:35

I almost forgot: is PowerSave possible for BK7525?
Then we should try if we need adjustments here, too.
And the same for BK7238. Did I miss something about PowerSave? Should it work?
#97 21623607 01 Aug 2025 23:31

divadiow divadiow

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Post #97
21623607 01 Aug 2025 23:31

max4elektroda wrote:
I almost forgot: is PowerSave possible for BK7525?

appears to. powersave 0 = 0.11A. Powersave 1 = ~0.2A

these higher-latency pings are powersave 1
#98 21623698 02 Aug 2025 08:47

max4elektroda max4elektroda

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Post #98
21623698 02 Aug 2025 08:47

Sorry, bad question: will powersave change timing, if it's available?

Added after 6 [minutes]:

Do you recall if/how PowerSave works for BK7238?
I didn't get it to work but probably only missed how it works there...
#99 21623703 02 Aug 2025 09:32

divadiow divadiow

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Post #99
21623703 02 Aug 2025 09:32

max4elektroda wrote:
Sorry, bad question: will powersave change timing, if it's available?

will check

max4elektroda wrote:
Do you recall if/how PowerSave works for BK7238?

not sure it does! https://www.elektroda.com/rtvforum/topic4127149.html

unless fixed since. can check

Added after 41 [minutes]:

good timing @insmod

Code: Text
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https://github.com/openshwprojects/OpenBK7231T_App/pull/1745

#100 21624160 02 Aug 2025 19:57

max4elektroda max4elektroda

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Post #100

21624160 02 Aug 2025 19:57

BK7238 will need some powersave-adjustment, added the code.
As soon as @insmod s PR fixing powersave is merged, it should work after syncing this PR

I saw some timeouts and a few CRCs, but generally its working o.k. with powersave:


Info:SENSOR:DS1820[9] - Temp=25.00
Info:MAIN:Time 667, idle 61945/s, free 115104, MQTT 0(42), bWifi 1, secondsWithNoPing 601, socks 2/24 POWERSAVE
Info:MAIN:Time 668, idle 64117/s, free 113928, MQTT 0(42), bWifi 1, secondsWithNoPing 602, socks 2/24 POWERSAVE
Info:MAIN:Time 669, idle 57772/s, free 115088, MQTT 0(42), bWifi 1, secondsWithNoPing 603, socks 3/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:MAIN:Time 670, idle 55622/s, free 123992, MQTT 0(42), bWifi 1, secondsWithNoPing 604, socks 2/24 POWERSAVE
Info:SENSOR:DS1820[9] - Starting conversion
Info:MAIN:Time 671, idle 61380/s, free 115688, MQTT 0(42), bWifi 1, secondsWithNoPing 605, socks 2/24 POWERSAVE
Info:SENSOR:DS1820[9] - Temp=25.00
Info:MAIN:Time 672, idle 64249/s, free 123408, MQTT 0(42), bWifi 1, secondsWithNoPing 606, socks 3/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:MAIN:Time 673, idle 49489/s, free 115688, MQTT 0(42), bWifi 1, secondsWithNoPing 607, socks 2/24 POWERSAVE
Info:MAIN:Time 674, idle 61657/s, free 115688, MQTT 0(42), bWifi 1, secondsWithNoPing 608, socks 2/24 POWERSAVE
Info:MAIN:Time 675, idle 27978/s, free 115688, MQTT 0(42), bWifi 1, secondsWithNoPing 609, socks 2/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:SENSOR:DHT timeout waiting for start signal high pulse.
Info:SENSOR:DS1820[9] - Starting conversion
Info:MAIN:Time 676, idle 51902/s, free 114016, MQTT 0(42), bWifi 1, secondsWithNoPing 610, socks 2/24 POWERSAVE
Info:SENSOR:DS1820[9] - Temp=25.00
Info:MAIN:Time 677, idle 68400/s, free 115600, MQTT 0(42), bWifi 1, secondsWithNoPing 611, socks 2/24 POWERSAVE
Info:MAIN:Time 678, idle 60156/s, free 115584, MQTT 0(42), bWifi 1, secondsWithNoPing 612, socks 2/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:MAIN:Time 679, idle 59934/s, free 115600, MQTT 0(42), bWifi 1, secondsWithNoPing 613, socks 2/24 POWERSAVE
Info:MAIN:Time 680, idle 69868/s, free 115688, MQTT 0(42), bWifi 1, secondsWithNoPing 614, socks 2/24 POWERSAVE
Info:SENSOR:DS1820[9] - Starting conversion
Info:MAIN:Time 681, idle 62448/s, free 115688, MQTT 0(43), bWifi 1, secondsWithNoPing 615, socks 2/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:SENSOR:DS1820[9] - Temp=25.00
Info:MAIN:Time 682, idle 64128/s, free 115080, MQTT 0(43), bWifi 1, secondsWithNoPing 616, socks 2/24 POWERSAVE
Info:MAIN:Time 683, idle 60101/s, free 114056, MQTT 0(43), bWifi 1, secondsWithNoPing 617, socks 2/24 POWERSAVE
Info:MAIN:Time 684, idle 62179/s, free 115688, MQTT 0(43), bWifi 1, secondsWithNoPing 618, socks 2/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:MAIN:Time 685, idle 62701/s, free 110968, MQTT 0(43), bWifi 1, secondsWithNoPing 619, socks 3/24 POWERSAVE
Info:SENSOR:DS1820[9] - Starting conversion
Info:MAIN:Time 686, idle 67751/s, free 111352, MQTT 0(43), bWifi 1, secondsWithNoPing 620, socks 3/24 POWERSAVE
Info:SENSOR:DS1820[9] - Temp=25.00
Info:MAIN:Time 687, idle 60005/s, free 114144, MQTT 0(43), bWifi 1, secondsWithNoPing 621, socks 2/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:MAIN:Time 688, idle 60500/s, free 114016, MQTT 0(43), bWifi 1, secondsWithNoPing 622, socks 2/24 POWERSAVE
Info:MAIN:Time 689, idle 64545/s, free 115688, MQTT 0(43), bWifi 1, secondsWithNoPing 623, socks 2/24 POWERSAVE
Info:MAIN:Time 690, idle 45499/s, free 115088, MQTT 0(43), bWifi 1, secondsWithNoPing 624, socks 3/24 POWERSAVE
Info:SENSOR:DHT start, pin is 7
Info:SENSOR:DS1820[9] - Starting conversion
Info:MAIN:Time 691, idle 101536/s, free 115688, MQTT 0(43), bWifi 1, secondsWithNoPing 625, socks 2/24 POWERSAVE
Info:SENSOR:DS1820[9] - Temp=25.00
Info:MAIN:Time 692, idle 58883/s, free 115104, MQTT 0(43), bWifi 1, secondsWithNoPing 626, socks 3/24 POWERSAVE

#101 21624172 02 Aug 2025 20:04

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

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Post #101
21624172 02 Aug 2025 20:04

Hey is @insmod PS fix tested and ready to merge?

I am creating multiplatform open source firmware (Tasmota replacement), right now supporting BK7231T, BK7231N, XR809, BL602, W800, W600, LN882H and soon supporting RTL and W701:
https://github.com/openshwprojects/OpenBK7231T
If you like my work, support me at: https://paypal.me/openshwprojects

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#102 21624381 03 Aug 2025 07:07

insmod insmod

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Post #102
21624381 03 Aug 2025 07:07

>>21624172
I guess? The only untested thing is spi on BK7231U/T_ALT and BK7238/N_ALT.
I don't have anything to test it with.
Though it can be merged even if it's not working.
#103 21624798 03 Aug 2025 16:08

max4elektroda max4elektroda

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Post #103
21624798 03 Aug 2025 16:08

Updated PR #1727, BK2738 now also works with powersave (tested DS18B20 and DHT11) .
Maybe @divadiow can check with DHT22, too?
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#104 21624810 03 Aug 2025 16:23

divadiow divadiow

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Post #104
21624810 03 Aug 2025 16:23

powersave 1

chip temp isn't quite right on BK7238
#105 21624824 03 Aug 2025 16:34

max4elektroda max4elektroda

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Post #105
21624824 03 Aug 2025 16:34

You also recognized it "freezing" from time to time??

I only saw this with powersave, but must admit I didn't try too long without ...
#106 21624828 03 Aug 2025 16:39

divadiow divadiow

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Post #106
21624828 03 Aug 2025 16:39

not noticed any freezing. chip temp is the same with 1.18.145 and no powersave
#107 21624835 03 Aug 2025 16:45

max4elektroda max4elektroda

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Post #107
21624835 03 Aug 2025 16:45

Sorry, meant as a joke: temp below -40°C --> "freezing"
#108 21624836 03 Aug 2025 16:46

divadiow divadiow

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Post #108
21624836 03 Aug 2025 16:46

ah! knew it. I did wonder but.. nm
#109 21626918 05 Aug 2025 21:22

divadiow divadiow

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Post #109
21626918 05 Aug 2025 21:22

insmod wrote:
The only untested thing is spi on BK7231U/T_ALT and BK7238/N_ALT.

dug this out

4m/60 WS2812B. OTA to latest _ALT

SPI/PixelAnim works but the colours are off. Less noticeable when the animation, especially rainbow, is running, but here's the starting RGB at power-on.
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Topic summary

The discussion centers on extending the DS18(B)20 temperature sensor driver in the OpenBeken IoT firmware to support multiple GPIOs and multiple sensors per GPIO. The original OneWire protocol timing was stable, so the focus shifted to refactoring the driver by separating basic OneWire functions into a shared file for reuse between simple and extended drivers. Key challenges include managing flash memory size, maintaining backward compatibility, and deciding whether to maintain two separate drivers (simple and full) or merge them with conditional compilation. The extended driver increases memory footprint due to more general and debug-capable code. Flash size impact varies by platform, with Beken-N showing no visible change and others like W800 and BL602 increasing by about 130-150 bytes. The multiline command feature requires enabling OBK scripting and is currently limited to Beken platforms but may be extended. User interface considerations include possibly using a Web App for configuration. Issues with sensor behavior on certain channels (notably channel 1) were noted, linked to external commands referencing channels (e.g., Tasmota commands). The discussion also touched on DST offset parsing improvements for timezone commands, balancing user-friendliness and code size. Overall, the consensus leans toward merging the extended driver with careful size optimization and backward compatibility, while keeping the option for a simpler driver for users with minimal sensor needs.
Summary generated by the language model.

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Extending DS18(B)20 driver - multiple GPIOs and multiple sensors per GPIO

FAQ

TL;DR: The new “full” DS18B20/DS1820 driver lets OpenBeken read dozens of 1-Wire temperature sensors on several GPIO pins, each with its own name and channel, while the ‘simple’ variant still handles a single probe per pin. Footprint difference in simple build is now only ~150 B [Elektroda, max4elektroda, post #21591096]

Quick Facts


Interface : 1-Wire, open-drain, needs ≥4.7 kΩ pull-up [Maxim DS18B20 datasheet]
Addressing : 64-bit unique ROM; driver auto-discovers via SearchROM algo [Analog AN187]
Read interval : Configurable, default 15 s (startDriver DS1820) [Elektroda, 21585693]
Resolution : 9–12 bit; many clones ignore SetResolution and lock at 12-bit [Elektroda, 21585693]
Code size delta : +6 kB in sensors build; +≈150 B in simple build after refactor [Elektroda, 21591096]

What does the extended DS18B20 driver add?

It supports multiple sensors on one or many GPIOs, stores each 64-bit address, lets you name sensors (e.g. “Kitchen”), maps every probe to an OpenBeken channel and offers a GUI plus command generator for backup [Elektroda, 21585693]

How do I enable it?

Issue startDriver DS1820 . The firmware scans every GPIO set to role DS1820_IO, discovers all ROM codes and starts periodic temperature conversion [Elektroda, 21585693]

How many sensors can share one pin?

Up to the 1-Wire electrical limit (tens of devices) as long as the bus length is short and a 4.7 kΩ pull-up is fitted [Maxim DS18B20 datasheet]. Test rig in the thread runs 7 sensors on a single GPIO without errors [Elektroda, 21585693]

How do I give sensors human-readable names?

Run DS18B20_setsensor "" "" [channel]. The command stores name, pin and optional channel in flash [Elektroda, 21585693]

Does scanning erase my manual configuration?

Yes. DS18B20_scansensors wipes the table and rebuilds it from the bus. Re-apply saved commands or use the GUI’s backlog script to restore [Elektroda, 21585693]

Why won’t SetResolution work on my probes?

Many low-cost DS18B20 clones ignore the resolution register and always output 12-bit data. The driver reports this limitation in logs [Elektroda, 21585693]

What is the memory impact?

Simple build grows by ≈150 bytes; sensors build grows by ~6 kB because it adds the GUI and ROM-search routine [Elektroda, 21591096]

Can I still use the lightweight single-sensor code?

Yes. Project maintainers opted for two mutually-exclusive drivers: DS1820 (simple) and DS1820_FULL (multi-sensor). Select the one you compile in obk_config.h [Elektroda, 21595460]

How do I batch-restore settings after reboot?

Copy the GUI-generated backlog (or multiline script) into autoexec.bat. Each DS18B20_setsensor call reloads saved names, pins and channels [Elektroda, 21585693]

Is multiline command input always available?

Multiline startup commands require ENABLE_OBK_SCRIPTING in obk_config.h; otherwise use a single backlog line [Elektroda, p.kaczmarek2, post #21586015]

Which platforms include the sensors build by default?

Currently only BK7231 (Beken) nightlies publish OBK-Sensors images; others can enable it by editing obk_config.h and compiling locally [Elektroda, 21586015]

Do I need a pull-up resistor on each GPIO?

Typical designs share one 4.7 kΩ resistor per 1-Wire bus. Using HAL_PIN_Setup_Input_Pullup may remove the external resistor on some MCUs, but external pull-up remains safest for long cables [Elektroda, 21585693]