[uncle_bob]

the temperature is reading a pretty cold -2507.9 degrees and 4071.3 for humidity!!

That looks like a reading where there is actually no reading. I take you changed the Sketch back for a DHT22 type?
If so I'd suspect it's faulty. Got a spare?

Note that these don't tolerate being wired up incorrectly, even for the briefest moment.

[AllanG]

the temperature is reading a pretty cold -2507.9 degrees and 4071.3 for humidity!!

That looks like a reading where there is actually no reading. I take you changed the Sketch back for a DHT22 type?
If so I'd suspect it's faulty. Got a spare?

Note that these don't tolerate being wired up incorrectly, even for the briefest moment.

Yes, I altered the configuration to DHT and was also very careful with the connections so nothing wrong there. Having looked at the circuit diagram the data pin's directly connected to Nano pin D9 so there's no other components that could cause problems. I've also substituted another Nano but still the same, so I too suspect it is a faulty DHT22 but good to have that confirmed. Unfortunately I only ordered the one so no spare.

I'll contact the ebay supplier and ask what they're going to do - and how quickly......!!

Thanks again for the help and support.

Allan.

[werk_ag]

Hi Allan

If you have any small breadboard you can easily test the sensor.
You can find here some info about how to do it:
https://sites.google.com/site/howfasthow...idthedht22


Here is the DHT22 pinout:



I already have heard of some DHT22 with the GND swapped with the NC pin.
It's safe connect both together. On the RX board the two are connected to GND.

[AllanG]

Hi Allan

If you have any small breadboard you can easily test the sensor.
You can find here some info about how to do it:
https://sites.google.com/site/howfasthow...idthedht22


Here is the DHT22 pinout:



I already have heard of some DHT22 with the GND swapped with the NC pin.
It's safe connect both together. On the RX board the two are connected to GND.

Thanks for the suggestion. I don't have a breadboard (maybe this is a good time to ask Santa.. ) but it wouldn't be difficult to connect the sensor with a spare Nano to test. I have tried connecting pins 3 & 4 to gnd but it doesn't make any difference.

I'll let you know what happens when I get a spare or replacement sensor.

Thanks again.

Allan.

[AllanG]

Now I'm really puzzled!

I bought another DHT22 which arrived today and I installed it right away. I was quite excited as I powered up the RX board and really expected to see it work properly. I was disappointed though - the results are still the same as before.

Checked again and all is well on the RX board with 5v at the DHT22 where it should be, ground connection ok and data pin connected to the Nano. 10K Resistor R4 is in place and gives correct reading when I check between pins 1 & 2 on the PCB with sensor disconnected.

So I made up a test lead and checked the DHT22 which does appear to be working (actually the first one is too ) as I get the following on serial monitor:

# DHT22 Sensor Demo
24.30:71.40
24.10:74.20
24.10:74.50
24.10:75.10
23.70:67.90
23.70:69.20
23.70:71.60
23.80:71.00
23.60:68.10
23.50:65.80
23.30:63.00
23.20:59.40
23.00:57.40
22.90:56.90
22.80:56.00
22.70:55.50

I just can't see any hardware issues that can be causing the problem. Is there anything in software I need to check, please??

Allan.

[werk_ag]

Hi Allan
With the Arduino Nano in place, could you please check if you have connectivity between the Dat pin at DHT22 connector and Arduino Nano pin D9.

Another thought: Are you using the DHT library supplied in the software package.

The only setting in the RX software to use the DHT22 sensor, is this:

Code:

// --- Define the type of your inside Temperature / Humidity Sensor
#define InsideTH_Sensor  0   // 0= DHT22, 1= HTU21D

I'm absolutely sure that the RX software is working properly with a DHT22 sensor, I have units working with it.

[uncle_bob]

Maybe try lifting one end of the 10K resistor then check for continuity from the Dat line to the top of the Nano pin D9 (I'm thinking that the Nano may have a bad solder joint on this pin).

Edit: Beaten by Werk by this -- much

[werk_ag]

Hi uncle_bob

Yeah, we are thinking the same thing. A possible problem in the connection between the Dat pin and D9.
Sometime I had a similar problem with a socket. Everything was well when checking at the socket pins at the board, but when I put the Nano on the socket, one of the pins have no contact.

[uncle_bob]

Werk_AG, are there any pass though holes, can't remember correct term at the moment (via maybe?), from one side to the other side of the PCB? If so, maybe it hasn't been filled with solder at the factory?

[werk_ag]

Yes, there are two in that line.
A problem with the vias can also be a possibility, despite until now I haven't any report about a similar problem. The next step after a simple continuity test between Dat and D9 pin, will be testing any of the two pass-through vias on the board.