Search found 21 matches
- 16 May 2019, 09:59
- Forum: ESP Easy: Hardware
- Topic: Temperature sensors - which are most precise?
- Replies: 12
- Views: 33398
Re: Temperature sensors - which are most precise?
I've made something like that some time ago :) I have multiple (about 10 or so DHT21), about 5 HTU21\SI7021, 5 SHT20 and 5 SHT30\31 and one BME280 My personal conclusion (based on few month of test at same location) - htu21\Si7021\SHT20\SH30 are showing the same results (difference usually not more ...
- 09 Apr 2019, 12:15
- Forum: ESP Easy: Hardware
- Topic: Reboot cause: WEMOS D1 (clone) voltage regulator ??
- Replies: 10
- Views: 27255
Re: Reboot cause: WEMOS D1 (clone) voltage regulator ??
Thanks a lot! I have one project on wemos D1 clone and was wondering why it reboots frequently. Now I know why 

- 19 Mar 2019, 15:35
- Forum: ESP Easy: Hardware
- Topic: MH-Z19 calibration issues
- Replies: 15
- Views: 21273
Re: MH-Z19 calibration issues
Another option - is to put sensor outside for 25 hours with ABC on. Anfter 25+ hours turn off and use without ABC
That what I did with my MH-Z19Bs (2 pcs). now they show almost the same values ans SenseAir S8.

- 08 Feb 2019, 14:45
- Forum: ESP Easy: Hardware
- Topic: Sensair S8
- Replies: 118
- Views: 153054
Re: Sensair S8
crazy, could the PSU be the reason? Now I'm using a 3 amps 5VDC. Check provided voltage (not ampers), that could be a reason. I've tried to power my device (see PCB above) directly from mikrotik router (it has USB input) and as result I got about 2000ppm. Then I've connected another device (both wi...
- 28 Jan 2019, 12:38
- Forum: ESP Easy: Hardware
- Topic: Sensirion SHT20
- Replies: 5
- Views: 8443
Re: Sensirion SHT20
Anyway, adopted this plugin to latest mega and sht20 works. Thanks
As result I have working sht20 and some fantom reboots, but that's not a big problem.

- 26 Jan 2019, 13:32
- Forum: ESP Easy: Hardware
- Topic: Sensirion SHT20
- Replies: 5
- Views: 8443
Re: Sensirion SHT20
Any news here? Have SHT20 that not working with Si7021 plugin
But wirking on other firmwares.
https://www.aliexpress.com/item/SHT20-D ... 23015.html

https://www.aliexpress.com/item/SHT20-D ... 23015.html
- 14 Jan 2019, 17:48
- Forum: ESP Easy: Hardware
- Topic: Sensair S8
- Replies: 118
- Views: 153054
Re: Sensair S8
If you use hardware serial you need to turn the serial communication off in the advanced settings. Or else the S8 and ESP will talk to each other - not understanding a word. Didn't help :( mega-20190110 doesn work mega-20180209 - work both: GPIO-13 GPIO-15 mega-20190110 : HW Serial Swap and Enable ...
- 14 Jan 2019, 08:14
- Forum: ESP Easy: Hardware
- Topic: Sensair S8
- Replies: 118
- Views: 153054
Re: Sensair S8
Thanks. I'll try and report in the evening.grovkillen wrote: ↑14 Jan 2019, 08:12 If you use hardware serial you need to turn the serial communication off in the advanced settings. Or else the S8 and ESP will talk to each other - not understanding a word.
- 14 Jan 2019, 07:40
- Forum: ESP Easy: Hardware
- Topic: Sensair S8
- Replies: 118
- Views: 153054
Re: Sensair S8
btw, I've fixed my PCB by cutting built in roads and adding external wires 
And interesting moment. With latest espeasy version, S8 doesn't work with my wemos. But everything is perfect with version from February 2018. Not a big problem for me, but...

And interesting moment. With latest espeasy version, S8 doesn't work with my wemos. But everything is perfect with version from February 2018. Not a big problem for me, but...
- 13 Jan 2019, 06:28
- Forum: ESP Easy: Hardware
- Topic: Sensair S8
- Replies: 118
- Views: 153054
Re: Sensair S8
If you upload some photos maybe we can help? Perhaps as simple as only use pinheaders on the two unused holes and wire which can be crossed to connect RX to TX etc .. I've tried with wires (no PCB) and yes, ESP can't load with this: GPIO (8) <--> TX GPIO (7) <--> RX I don't understand why :( I real...
- 12 Jan 2019, 21:15
- Forum: ESP Easy: Hardware
- Topic: Sensair S8
- Replies: 118
- Views: 153054
Re: Sensair S8
Hi all! I have some problems on connecting S8 to ESP8266. I've ordered my first PCB, but somehow (don't ask why :) ) I've made mistake on layout. According to this: https://www.letscontrolit.com/wiki/index.php/S8 GPIO (7) <--> TX GPIO (8) <--> RX And my PCB: GPIO (8) <--> TX GPIO (7) <--> RX Problem...
- 22 Jan 2018, 08:59
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
I've finished with my tests (MH-Z19B vs SenseAir S8). So, finally MH-Z19B is very good with ABC turned OFF (and properly calibrated, of course). At the same time MH-Z19B very bad if you room not ventilated every day. Here is graph of two MH-Z19B (both with ABC turned OFF!) and one S8. Average differ...
- 15 Jan 2018, 19:15
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
Yep, but mine is newerTD-er wrote: ↑15 Jan 2018, 16:52 This one is more readablehttp://www.winsen-sensor.com/d/files/in ... ver1_0.pdf

- 15 Jan 2018, 15:03
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
Small update.
Room wasn't ventilated properly for 26 hours (it was just before previous calibration). And now MH-Z19B (ABC) calibrated. From +100ppm (comparing to S8) to -100ppm...
Lowest ppm during last 24h was 600ppm. So MH-Z19B now thinks that this 600ppm is 400ppm... Terrible behavior.
Room wasn't ventilated properly for 26 hours (it was just before previous calibration). And now MH-Z19B (ABC) calibrated. From +100ppm (comparing to S8) to -100ppm...
Lowest ppm during last 24h was 600ppm. So MH-Z19B now thinks that this 600ppm is 400ppm... Terrible behavior.
- 15 Jan 2018, 14:20
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
That looks quite nice, the scatter plot. So if you're running for a while, the version with ABC should show some drift and thus a wider band? Also interesting to "swap" the data by placing other sensors on the X-axis. Yes, I'll create different graphs after few weeks of testing BTW, have ...
- 10 Jan 2018, 22:36
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
Implemented scatter 
ppm reported every 1 minute. For graph grouped by 5 minutes. Data for last day (after 5 days of running)
And basic chart (same data)
average difference for MH-Z19B without ABC is only 41 ppm! For ABC version is 95 ppm (and its increasing each day, damn 1 day calibration)

ppm reported every 1 minute. For graph grouped by 5 minutes. Data for last day (after 5 days of running)
And basic chart (same data)
average difference for MH-Z19B without ABC is only 41 ppm! For ABC version is 95 ppm (and its increasing each day, damn 1 day calibration)
- 10 Jan 2018, 08:53
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
When you reboot, could you test with the latest source to see if the problems with the Generic HTTP Advanced are now fixed? Updated all 3 boards to latest sources (manually compiled) - still has problems with one board (reboots every 10-15 minutes). All boards identical (wemos mini 3.0.0). Bought t...
- 09 Jan 2018, 10:08
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
When you reboot, could you test with the latest source to see if the problems with the Generic HTTP Advanced are now fixed? Ok, I'll try to update to latest version. If you do the scatter plot, then you can see how well they correlate. And even 100 ppm off is not bad, as long as the average offset ...
- 09 Jan 2018, 09:00
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
Can you also write down what color in the graph what sensor is? About your last question. You can only add more than one when using different pins. The MHZ19 plugin uses the SoftSerial code, which allows multiple instances to be used. In the last Mega code, I changed it to max. 3 simultaneous insta...
- 05 Jan 2018, 09:20
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
co2.png Here is my tests of 4 sensors: MH-Z19B (named with ABC) MH-Z19B with ABC turned off MH-Z19 (named with ABC) MH-Z19 with ABC turned off (I know that there is nothing about ABC in MH-Z19 datasheet, but I've tried to turn it off) All 4 sesnosrs installed on one breadboard (and its about 2cm be...
- 20 Dec 2017, 08:33
- Forum: ESP Easy: Software
- Topic: MH-Z19 offset and scale differences!?
- Replies: 39
- Views: 62856
Re: MH-Z19 offset and scale differences!?
Happy to find this forum and this topic :) Already ordered few S8, but also have pair of MH-Z19 and pair of MH-Z19B. And my own tests are pretty the same as chunter1's! (for comparing 19 and 19B). MH-Z19 always shows ppm in about 200 less then MH-Z19B. Even after few days in well ventilated room. My...