I have soldered two emontx boards, they all look perfect and when I test them, 2 boards can load and run the program and RF works as well. however whenever I tested the CT sensor with the boards.
On the board 1, all three CT port doesn't work out. because when I attach one CT sensor ( the head of CT sensor is AC power ), the CT port still output almost the same values with the values without CT sensor. I tested with another emontx board 2, it works well on the port 1, because you can see the value incrementing when attaching the CT sensor, and value dropping immediately when detaching the CT sensor.
on the wrong board 1 all three ports not working. on the board 2 , only port 1 works.
i looked very carefully at the two boards, I don't see any bad solder in the wrong board, how can I test the wrong to see where goes wrong, more specific, what electronic components are involved in the electricity sensing in port 1, port 2, port 3, (because I am bad reading the circuits)
Use a digital multimeter and measure the voltage on the contact spring nearest to the edge of the board on the port. You should read approximately +1.65 V.
If you do not read 1.65 V, check that you have inserted C8, C9 and C11 the correct way round. The white stripe must be on the same side as in the photograph. Compare your board very carefully with the photograph here: http://openenergymonitor.org/emon/emontx Also check that you have inserted the correct value resistors everywhere.
How the current sensor input works is described here: http://openenergymonitor.org/emon/buildingblocks/ct-sensors-interface This page has an Arduino board working at 5 V. The EmonTx works at 3.3 V. Therefore on this page, change 5 V to 3.3 V and 2.5 V to 1.65 V.
Open-source tools for energy monitoring and analysis. This project uses the GNU General Public Licence