nice...
i got this reset stack now:

CO2 level: -10 ppm

Soft WDT reset

ctx: cont
sp: 3ffef1f0 end: 3ffef3d0 offset: 01b0

stack>>>
3ffef3a0: 00000000 00000000 00000001 40202281
3ffef3b0: 3fffdad0 00000000 3ffee39c 402022ac
3ffef3c0: feefeffe feefeffe 3ffee3b0 40100114
<<<stack<<<
?⸮⸮⸮⸮DH⸮⸮⸮CO2 level: 395 ppm
CO2 level: 395 ppm
CO2 level: -10 ppm
CO2 level: 405 ppm
CO2 level: 405 ppm
...
CO2 level: 1070 ppm
CO2 level: 1075 ppm
CO2 level: 1080 ppm
...

atleast now i know that it started the calibration from the start again, but what could it all mean?
and its probably best to use good quality cables too then... and perhaps good to not to touch the dupont cables too...

ok, so i got it working from the last link, but wonder what does this code do?
CO2= int(2000*(duration_h-2)/(duration_h+(1004-duration_h)-4));

and i actually changed it to this:
CO2=int(5000*(duration_h-2)/(duration_h+(1004-duration_h)-4));
(removed the space before "int" too)
and this code somehow has "-4" not "-2" as in this forum topic?

and it probably calibrates itself on the 1st startup hour and also does this every 24 hours?
so wonder if i need to place the sensor in a relatively clean air(on a window?) or it doesnt really matter? and it is of course a bit colder near the window because i also opened it a bit to let more clean air in.......
and when i first plugged it in, it started to show something like 495ppm, but then i unplugged it and took it to the window(in another room), and it then started from 1375ppm and has now been dropped down to 900....
so i wonder why did it first show 495, but then 1375 suddenly.....

so maybe pins 13-19 are 3,3 volts on the z14 and pins 1-12 are 5volts?

lol.... so i thought that maybe i could run it like this:
https://arduinomania.in.ua/datchik-co2-mh-z14
but what is the (T1)PD5/IO5 pin on the wemos board ? D3 or D4? maybe D3 as GPIO0 then???:-S
from here:
http://www.instructables.com/id/Programming-the-WeMos-Using-Arduino-SoftwareIDE/

so.. the main question here is.... do i need the wemos board in the Tristate/TTLadapter mode at all?
and this page here gives 3,3volts to the sensor?
https://www.14core.com/wiring-the-nondispersive-infrared-mh-z14-carbon-dioxide-gas-sensor-on-microcontroller/
and i basically soldered some connectors to the same exact pins.
but is the code for arduino ide at all? and if it is, then i basically do not need to use the Tristate/TTLadapter mode at all?
....
and the wiring guide and sensor schematics images do not match at all on that page ????????
so what the heck do i need to do to get some readings out of it......................

well, i got this far that i just soldered some connectors to pins 16-19 and now want to use the wemos board as USB to TTL adapter, so i could use the Co2 logger over python server, but how do i need to connect the Rx and Tx pins?

does it have to be like a crossover cable or just normal straight?
like Sensor Rx to Wemos Tx + S-Tx to W-Rx or just the regular connection like Rx to Rx and Tx to Tx?

edit*
lol.... the 16-19 pins maybe doesnt have this somekind of 3.3v query pin and only has 5V input? or Rx&Tx run at 3,3 volts?

hi
what could be the A0 and A1 pins on wemos d1?
i can only see A0 and D0, which are even on the opposite sides...
and if i use some arduino apps via IDE, then what could be the Pin number of the A0 on the wemos board?
its just way too weird that i cant get any information about this even from their own website....:
https://wiki.wemos.cc/products:d1:d1
or can i actually use the JP connectors somehow via the built-in usb to ttl adapter function ? (by connecting the reset and ground?)
https://wiki.wemos.cc/_media/products:d1:d1_v2.0.0.pdf
and is A1 below A0 then and i should connect the sensor(mhz14a) pins in there?
and would the z19 code work with z14a sensor too?

and of course.... what pins should i use on the sensor itself? like there seems to be atleast 3 different pin sets for rx+tx+gnd+v, and each of them have a different amount of double pins? like the 1-12 pin set has 3 ground pins and the 13-19 pin set has 2 Vin pins and also 2 rx and tx pins?:
http://www.winsen-sensor.com/d/files/infrared-gas-sensor/mh-z14a_co2-manual-v1_01.pdf
so which ones should i use when i dont want to use the small Uart(ttl?) port and its thin wires...

hi
this looks quite nice stuff, but how should i wire up the sensor to wemos d1 for example?
do i have to use the TTL adapter mode on the board by shorting some pins or do i just need to give some power to the sensor and hook the PWM pin to the wemos board somehow?

and how does this code comapre to these codes?
https://gist.github.com/igrr/deb7ba7755fcffe0b96e
https://github.com/ihormelnyk/mh-z19_co2_meter/blob/master/mh-z19_co2_meter.ino

or should i just get a usb/ttl adapter and use it over python then?
https://github.com/alpacagh/MHZ14-CO2-Logger