Banggood

datasheet in some aspects misleading. Finally I got it working. It now shows reasonable results. Quality looks good.

Bien reçu ce jour sans casse. Reste à tester.

Hi All, It can be hooked up to a simple usb/serial converter (only 4 wires required). Make sure the data lines (Tx and Rx) use 3V signalling. Running a simple powershell script the data is displayed. Script: [Byte[]] $request = 0xff, 1, 0x86, 0, 0, 0, 0, 0, 0x79 [Byte[]] $res = 0, 0, 0, 0, 0, 0, 0, 0, 0 $port = new-Object System.IO.Ports.SerialPort COM57,9600,None,8,one $port.Open() $port.Write($request, 0, 9) Start-Sleep -Milliseconds 50 For ( $i = 0; $i -lt 9; $i++ ) { $res[$i] = $port.ReadByte() } Write-Host

Seems to do what it says on the box. Inside with a gas heater (with flue) on I got (with the script above, cheers) an uncomfortably high reading >1200ppm so I took it outside and got 385ppm after a few minutes, which seems right. So I have a window open now :-)

Works as specified, worm up phase is longer than 3 minutes, but under 5 min. Supplycurrent is quit high with peaks, but on average also as specified.

it arrived in 2 weeks, in a good packaging. It works well. good deal.

Veio jogado dentro do pacote, sem proteção. Mas chegou ok. Não testei ainda.

хороший товар

Works very well, but the one I got has an internal thermometer that's off by around 6 Kelvin. This makes all measurements wrong, and I had to implement a 3-point (at least) calibration using a linear function of temperature and measured CO2 ppm. The good news is, the error is linear in those 2 variables, so 3 accurately measured calibration points with a reference sensor will do the job. Another good news is that the sensor actually reports its measured temperature along with the ppm number via UART. I

CO2 measurements is very good. No calibration needed. I wired it to a nodemcu with Tasmota firmware flashed. Taslota also shows the temperature but this value is way off, 17 degrees C higher than the actual temperature. Strange since this offset is identical over the full range (can be used if the offset is compensated in sw). The temperature is only with a 1 degree resolution (not 0.1).