I’ve read the manual for the MH Z16 Grove CO2 sensor and have one running. However I purchased another two via digikey and they do not return the correct bytes.
One of the sensors return bytes:
145 255 134 2 169 61 0 0 1
Which at first glance looks shifted as 255 and 134 should be the first two values received. The checksum does not add up for this.
The other sensor returns
174 16 32 64 184 11 0 0 184
Which is completely off spec…
Any advice on how to move forward? or do you reckon this is malfunctioning hardware. Weird that both of them dont work.
I’ve also powered it through a 2A powersupply incase for some reason internal resistance of the sensors were differnt and it wasn’t drawing enough current, but it doesn’t work.
for your reference 20170504 is the ID on the sensor.
Please paste up your circuit link diagram and run code, let me do a test here to solve the problem.
seeed techsupport team