[daveh]

My WD unit displays an ATM value of --- for long periods and then the correct pressure suddenly appears for a while before going back to ---. All other displayed values are correct and agree with the display of the TX unit. Pressure is always displayed on the TX unit. Have you got any suggestion why this is happening?

Software is WD 2.1-b001 and RX 2.1-b002

Thanks.

[MikeM]

I noticed the same issue.
Some days it would show the ATM value all the time, but on other days it does not show the value every now and then.
I'm not sure of the software version running on my WD, I need to check and update if necessary first.

[f4aii]

the pressure sensor is in the RX.
I had the same problem until I installed version 4

[daveh]

I thought Version 4 was only for the Pro2 Plus. Mine is the Pro2.

[werk_ag]

Any of those reported issues is more related with the communication between the RX and the WD units than with the software version.

There are many possible ways to solve this, some may work for some WD units and not for others, depending on each one instalattion.

One thing to always check is the blinking rate of the LED on the WD unit. A blink arround each 3 to 5 seconds, sometimes less, is a good indication of a good reception.

Some things that each one facing any of these issues could be try:

- Completely remove the antenna from the WD unit, and instead of it, solder a piece of isolated wire with 17cm to the center pin of the SMA connector.
This one is usefull in many cases.

- There are two antennas on the RX unit. Try put the transmitter antenna of the RX unit, in an oposite position to the receiver antenna: If one is in vertical position put the other in horizontal, and vice versa. Match the position of the WD antenna with the position of the transmitter antenna used on the RX unit.

These suggestions come from my personal experience. I have several WD units in different places of the house, to make all of them working well I had to apply some of the "techniques" described above.

[hornychz]

...
- There are two antennas on the RX unit. Try put the transmitter antenna of the RX unit, in an oposite position to the receiver antenna: If one is in vertical position put the other in horizontal, and vice versa. Match the position of the WD antenna with the position of the transmitter antenna used on the RX unit.

Hi all,

This is, by my opinion, VERY important information, the both antennas can interfere with each other!

Based on my experience, I recommend setting the receiving antenna on the RX unit with about 30°
offset from the vertical position (no more than 45°). All TX units should have the transmitting antenna
inclined in the same direction - ideally parallel should be. The intersection of the highest radiated power
must lie in the center of this RX antenna. We will use the receiving antenna on the RX unit ideally with
a bigger gain (beware - suppliers are often lying about its parameters) - about 6 dBi.

Conversely, for the transmit antenna on the RX unit we use a small antenna - 2 dBi, bend it to the horizontal
position and similarly to the antenna of the WD unit. The range gets smaller, but it could be enough in smaller houses.

But, as Werk_AG says, the right selection of antennas and their setting is a bit of ghost, a bit of alchemy ...

Good luck!

[daveh]

Interesting replies but if it's a communication problem why does it only affect pressure on the WD?. All other values are ok. Wind speed and direction updates every 5 seconds or so and the WD led flashes at about the same interval.

[werk_ag]

This issue may happen more frequently with pressure data, because ATM it is not sent so often as the other types of data. If reception is poor, and the WD looses 3 consecutive pressure data packets, the dashed lines will appear.

Playing with the antennas, and in extreme cases with the WD receiver module is the solution. I remember that some time ago, an user have reported an interesting case: Two identical WD units, running the same software version, placed side by side, one is receiving all the data while the other occasionally doesn't receive the external temperature data.



Just for you to be sure that the problem is related to communication, try change the position of the transmitter antenna on the RX unit and temporarily change the placement of the WD unit, by putting it farther of the RX unit, or closer, if it is already far.

[werk_ag]

...

Based on my experience, I recommend setting the receiving antenna on the RX unit with about 30°
offset from the vertical position (no more than 45°). All TX units should have the transmitting antenna
inclined in the same direction - ideally parallel should be.

Good point Zdenek,
For the TX - RX antennas, I agree completely with what you say.
After lots of climbs to the roof (on first year), and experiments in several positions (and almost all types of antennas I could find), I have found that the best results are obtained by placing the antennas the way you describe (in my case, vertical position doesn't work at all). On the last 3 years I haven't touched on the antennas a single time. With three TX units plus the AQM, efficiency runs stable around 60 to 75 for each TX unit.

I believe that what you describe its the best placement, especially for the cases where the TX units are installed above the receiver (most cases I think).

Regarding to the placement of the antennas of the WD units there is also other consideration, that we couldn't forget. The WD receiver, gets almost the double of the data packets of our main receiver. It receives all the data packets sent from the TX units, plus the ones that are sent specifically for it. The WD unit only knows what packets are for him after decoding them. So this is another reason for we to try to place the WD antennas in a way that is favourable to receive data from the main receiver and not favourable to receive from the TX units (don't know if I'm being clear).

There is another way to completely avoid collisions on the WD units, but may not be legal in all countries, however its very simple. Just change the transmitter module on the RX and the receiver module on the WD units with the 355Mhz versions. This way the data sent for the WD units will be sent in a completely different frequency.

All my transmitter modules used on the WeatherDuino are 433Mhz versions (I'm also using 355Mhz, but for other devices), so I opted to carefully test the best placement of the antenna used to relay data for the WD units. By experiment, I found that placing it horizontally in a way that is parallel to almost all the antennas of my WD units, gives me the best results. Interestingly one of my WD units, which isn't the closer nor the farther unit, only started to work reliably after replacing the SMA antenna by a 17cm wire.