CM2302 got done in
Early in the summer I had placed a cm2302 temp/humid sensor outside to data log the readings. Well last night the -13.50 degrees temperature put my cm2302 into a frozen state. So, far the readings keep showing -13.50 while the temperature outside is actually +3 degrees. Now I am wondering if the sensor is fried, no, I mean frozen, and no longer functional. I am hoping it is just in hibernation until the temps get well above 32 degrees.
Ray
Ray
Comments
You need to thaw it out.
Mike
-Phil
I guess I will have to start looking for a unit that can work in -20*F and at the top end, about 105*F.
Ray
I have the BME280 unit outside and it worked all the way down to -21 degrees this morning. No problem.
I did however have this same unit last year set out in the open and it failed at 20 degrees. I ended up replacing it only to find out that once I had it in the house a while it worked just fine.
I now have an enclosure around the unit and don't have a problem with it freezing up.
Mike
Right you are! I applied 5/9 instead of 9/5. D'oh!
-Phil
Ray
Ray
I did add some logic that tracks time and also a dead man switch.
So if the unit sends updates the timer will get reset. So far the unit has been running 26 days.
See for yourself: My weather station
Mike
Ray
I built an indoor unit that makes a web request to a site that gives me the forecast in my area. It works great for a while and then stops working. It make a web request every 10 minutes.
I recently replace it with my own ESP8266 unit running custom code and that works just fine.
Mike
Ray
Mike
Ray
At this point I am not sure if the Activity Board has also been compromised in some way. This has turned out to be a real hassle, not sure what I will have to do too fix the problem. It is not like this unit is in some harsh conditions, it just runs 24/7 for months on end.
Yes, as of yesterday, the cm2302, is showing the temperature correctly, but the humidity readings are still at 99.90 degrees. So, that is another puzzle that has to be solved.
If a majority of the products that make up the Activity Board, Parallax WiFi, and the cm2302 are made in China, then I am becoming very cautious about buying anything that is electronic that has its origins in China. Hmm, what to do?
Ray
The way it is configured is that I first programmed the XBee to sleep for 1 minute and then wake up for 10 seconds.
In my program then I monitor the CTS pin and when it goes high I gather the weather data and send it as serial UDP data out to my network. Then the XBee goes back to sleep.
There is no fancy setup code for the XBee in my program and the XBee is set to transparent mode so all I do is send the data at 9600 baud to the serial port of the XBee. The XBee builds the packet and sends it.
The thinking was that I could save power and run it from batteries but the propeller uses to much power.
Since this module fits in the same place as the ESP module it would be a plugin replacement.
Parallax used to sell that item but not anymore.
Mike
Ray
https://www.kandrsmith.org/RJS/Misc/hygrometers.html
Also includes
Bosch Sensortec BME280
Measurement Specialties HTU21D
Silicon Labs Si7021
Sensirion SHT71, SHT31
Aosong DHT11, DHT22, AM2302, AM2320, AM2321
They didn't have means to test below freezing though. I believe that the AM2302 and the CM2302 are equivalent--not sure though.
Now the new unit has gone bad also. The temperature reading is stuck at 65.10 *F. This module only took a month to get done in, not sure what the heck is going on with these modules. Did I get the only bad ones from a large production run. Boy, what luck I must be having with these units. I have a module that I am using inside the house, no problem with that unit. I guess I will have to take that one outside, just to see if that one goes bad also. Then I guess I could say that the CM2302 modules are not recommended for outdoor use.
Ray
For the CM2302
any code available for P1 I can only find code for P2
If you are up for some Blockly code:
https://learn.parallax.com/support/reference/propeller-blocklyprop-block-reference/sensor/temp-humidity/temperature-humidity
Blockly produces C code.
No, Blockly is easy to find - I want spin for P1. I found spin for P2 - guess that will not work on P1
thanks
Here is a spin file I found a while ago for the CM2302. It contains a P1 PASM driver implementation for the CM2302. I don't know if this will help you or not, but it is for the P1. As for the P2 spin you found, it may be possible to still use it on the P1, it will depend on the commands/methodology used.
well, with flexspin you can compile P2 Spin for the P1 as long as there is no pasm involved
mike