SEN0219 sensor calibration
mpocatko 2018-09-25 04:18:35 4473 Views3 Replies Hello, I've got some trouble understanding how to calibrate the sensor from its wiki page
Quote from the page:
I have tried to let it run for 24 hours, which didn't work.
Also, I don't know if it's important, but I'm not using it with arduino, I'm using pycom, which only takes 3V3 sensors. But in the beginning it was running just fine.
Quote from the page:
Does this mean I should just hardwire hd pin to a ground and let it run normally?Q. How do I make a Calibration?
A. The sensor should be calibrated regularly. The cycle time is better to be no more than 6 months. Manual calibration of zero point is to calibrate the sensor's HD pin input low level (0V) to calibrate the zero point, and the low level shall last more than 7 seconds.The calibration of zero point is 400 ppm, Please ensure that the sensor is stable for more than 20 minutes at 400ppm.
I have tried to let it run for 24 hours, which didn't work.
Also, I don't know if it's important, but I'm not using it with arduino, I'm using pycom, which only takes 3V3 sensors. But in the beginning it was running just fine.
2018-09-26 10:12:02 Hi.
I mean the sensor needs 5v power,your computer 5V source connect to the pycom and pycom output 3.3V,But the sensor need 5V power to work properly.
You can find HD pins from the white screen of the sensor's green bottom board,Its position is the third one from right to left in the first row.You can just connect it to GND,so,it will keep low level.The zero point is 400 ppm and the zero calibration command is the computer's instructions to the sensor.I will send you a document, I hope it can help you.
Sorry, bad community can not upload PDF documents, I can only give you pictures makermuyi
I mean the sensor needs 5v power,your computer 5V source connect to the pycom and pycom output 3.3V,But the sensor need 5V power to work properly.
You can find HD pins from the white screen of the sensor's green bottom board,Its position is the third one from right to left in the first row.You can just connect it to GND,so,it will keep low level.The zero point is 400 ppm and the zero calibration command is the computer's instructions to the sensor.I will send you a document, I hope it can help you.
Sorry, bad community can not upload PDF documents, I can only give you pictures
makermuyi 2018-09-26 02:40:03 Hi, thank you for your answer.
I am very new when it comes to working with sensors like this, and there are a few things I don't fully understand yet.
First of all, I am running it from 5v source and computing the value appropriately, that's definitelly not an issue, because it was running fine in the beginning.
So first thing i'd like to know is how to locate and access the hd pin. I can't see it anywhere in the sensor documentation. I see it marked on the board, but is the only way to access it soldering a cable to it?
Second, I'd like to know how to keep its input at low level.
And third, what is a zero calibration command, I don't see it anywhere in pycom documentation.
Thank you. mpocatko
I am very new when it comes to working with sensors like this, and there are a few things I don't fully understand yet.
First of all, I am running it from 5v source and computing the value appropriately, that's definitelly not an issue, because it was running fine in the beginning.
So first thing i'd like to know is how to locate and access the hd pin. I can't see it anywhere in the sensor documentation. I see it marked on the board, but is the only way to access it soldering a cable to it?
Second, I'd like to know how to keep its input at low level.
And third, what is a zero calibration command, I don't see it anywhere in pycom documentation.
Thank you.
mpocatko 2018-09-25 10:24:00 Hi.
I'm sorry to reply you late.
If you want to manual calibrate the CO2 sensor, First,Because that you using pycom and pycom only support 3.3V voltage, so when you using 3.3v devices, please still use 5V power to power the sensor, and modify the corresponding relationship in the code. float voltage = sensorValue*(5000/1024.0); Second,you should keep the sensor's HD pin input low level (0V) last more than 7 seconds.Before runiing the zero calibration command, ensure the sensor operates steadily at a concentration of 400ppm for more than 20 minutes.
Hope help you. makermuyi
I'm sorry to reply you late.
If you want to manual calibrate the CO2 sensor, First,Because that you using pycom and pycom only support 3.3V voltage, so when you using 3.3v devices, please still use 5V power to power the sensor, and modify the corresponding relationship in the code. float voltage = sensorValue*(5000/1024.0); Second,you should keep the sensor's HD pin input low level (0V) last more than 7 seconds.Before runiing the zero calibration command, ensure the sensor operates steadily at a concentration of 400ppm for more than 20 minutes.
Hope help you.
makermuyi 