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Ah thanks for alerting me to the temperature sensor issue. I realise when I wrote the documentation and the firmware I was using a prototype version of the emonTx V3 (V3.0). The production version is V3.2. In V3.2 (the version you have) Dig 5 is data and Dig19 is power. I have updated the firmware to reflect this change. It should work if you upload the latest firmware from github (recommended), or you could just swap the data and power wires (red and white) round on the terminal block. Please let me know if this fixes it, very sorry for the hassle:

https://github.com/openenergymonitor/emonTxFirmware/tree/master/emonTxV3/RFM12B/emonTxV3_RFM12B_DiscreteSampling

We have not yet decided what the best SMA options to offer in the shop are yet. We need to do some testing. I have made a table with all the options and part numbers on the wiki. I think the best option could be the Ciseco whip antenna with a 5m cable which would allow the antenna to be placed up high somewhere for installations which tricky RF issues. http://wiki.openenergymonitor.org/index.php?title=EmonTx_V3#SMA_Antenna_options.

If you do go down the SAM route, please share your experiences

Thanks ever so Glyn,

I've ordered a bunch of SMA things to play with and will report back. My original motivation was that the little whip antenna has detached (slighly poor solder job and too close to the edge of the board). Have since re-soldered, but it's still naff and will break again.

If I simply stick an SMA socket into the board and solder, will that work ? Do I need to jumper anything or are all the necessary PCB tracks in place ?

On the temperature front, I'll attempt to load up the new firmware (not done it before) .. thanks again for super quick reply and on a Saturday too !

Another thing I have noticed is that it's not obvious the reset button works. Once the board is inserted into the case, it's the only way to get the sensors noticed (I am running on batteries which are inaccessible inside the case). On pressing reset the red led does not do anything. Only way I can make it work right now (on batteries) is to leave it out of the case, plug in the sensors and then apply power (by removing and then inserting one of the batteries).

Pat

No, no Jumpering is required. Just solder on the sma connector. 

Sorry, please let me correct myself: no jumpering is required if the RFu328 is soldered onto the emonTx V3 PCB via SMT, if Xbee style 2mm headers are used you will need to insert a little section of wire to join the ant connection on the RFu328 to the PCB. This can be a bit fiddly. 

That does not sound right, the reset should instantly reset the board making the red led come on for 10s. Does the reset button not work at all? Do you think it's a mechanical thing? Do you feel a click when you press the button? If it is broken we would be most happy to replace the emonTx for you. This is the first we've heard of such an issue. I will do some random tests on the EmonTx V3's which we have in stock tomorrow.

Hi, sorry am confused again. Somewhat new to this. The RFu328 has an SMA (radio?) board soldered to it directly, but the RFu328 itself is plugged into some headers on the emonTX board. So I need to do a little soldering, correct ? See my little red arrows below !

On the reset button front, it does click, but is definitely faulty. I put a meter across the contacts on the rear of the PCB and they don't connect when the button in pressed. Shorting them with a bit of wire does the trick, so it looks like the button is faulty I am afraid :(

Pat

(ps again while I am here -- are there any reasonably idiot proof instructions for reprogramming the firmware with the .hex file from github (emonTxV3_RFM12B_DiscreteSampling.cpp433.hex)

Thanks!

Not those two pads! Only the one.

The easy way to explain this is to (conceptually) remove the headers and drop the RFu328 onto the pads aligned with its printed outline on the silk screen. Where the white wire antenna is soldered lines up with the left-hand of the pads you've arrowed. It's that pad which you link to where the wire antenna is now, i.e the link is almost perpendicular to the PCB.

Ok, I understand.

In practice then I'll snip down the existing white antenna cable (you can see in the picture) and solder to the left hand arrowed pad (with the vertical track to the centre pad of the SMA connector).

I had assumed (incorrectly) that the existing antenna was *also* connected to the right hand most arrowed pad, and hence my desire to solder the two together. 50% right is not that bad :) Though of course still 100% wrong !

The right-hand arrowed pad is 3.3 V. I've no idea what 3.3 V into the output stage would do, nor RF onto the supply, but I don't think it would be helpful!

I think I'd unsolder the existing antenna, take a bit of tinned copper wire and bend the last 2 mm at right angles. Solder that onto the PCB pad, then lean it up to the antenna pad on the RFu and solder there, then snip the surplus off.

Ok, is done and working great. For reference I used CPC for the SMA parts 

1) The PCB socket part# CN11117 - SOCKET, SMA R/A PCB; Body Style:Right An  5-1814400-1  TE CONNECTIVITY / AMP

2) A little stubby 433MHz antenna part# RF00296 - ANTENNA STUB R/ANGLED 434MHZ; SVHC:No SV  ANT-SR400    LPRS

Have not done a range test yet.

Pat

Today I have tested the firmware fix for the temperature sensor. It works great. However if you don't want to update the firmware you could just swap round the red and white wires, however this might cause confusion in the future. You can update the firmware using the Arduino IDE with a USB to UART cable. However it might be easier for you to flash the pre compiled .hex file directly with the new firmware. Instructions have been added to the wiki: http://wiki.openenergymonitor.org/index.php?title=EmonTx_V3#Uploading_Arduino_Firmware

I've added instructions for adding an SMA antenna together with illustration photos to the wiki http://wiki.openenergymonitor.org/index.php?title=EmonTx_V3#SMA_Antenna.

Again, thanks for being our guinea pig!

Oh dear, that's bad news regarding the reset switch. This is the first fault we have heard of with the switches. We would be happy for you to send the board back to us for replacement. If you like we could surface mount solder the RFu328 onto the PCB for you on your replacement board if you are keen to use SMA?

See here for our shop return address and direct support contact: http://shop.openenergymonitor.com/shop-info/ 

You will loose some power with the header version as the wire bridge won't be 50 Ohm so some power will be reflected back to the transmitter, although how much is anybody's guess.

Presumably the PCB track to the SMA connecter sits over a ground plane and is dimensioned for 50 Ohms?

Hi, thanks again for the really fantastic (and speedy!) support. Will have a go at updating !

For the time being I have done a bit of a bodge to connect the antenna track from the RFu to the main board. It's working fine, certainly at the relatively short range I am using (about 20m, though through several walls and floors). I think I prefer to have it mounted on the headers rather than SMA mounted at this stage ..

On the reset switch front, I'll just replace the switch to save all the hassle of sending back and forth. Not a big deal. Once I get the old switch out I can send it back if you want to do forensics on it (suspect it was just a dud).

Great stuff.

Just don't know actually .. working Ok as I said in my other post, though not a long distance trial !

SMA 90 degree PCB connector is now available in the shop: http://shop.openenergymonitor.com/sma-pcb-connector-90-degree/