08-04-2016, 17:44
(08-04-2016, 06:49)moolight0551 Wrote: Everything seems to check out., however I am puzzled by the Gnd of the RF_Tx connector(Tx v2.4) It does not connect to the other Gnd points or the backplane of the circuit board. Does the Tx module only power up momentarily when the Nano has data to send? Is this the role of the 2N7000?
Yes, it acts as a switch cutting the TX GND pin. The TX module is only powered some milliseconds before it starts to transmit data.
(08-04-2016, 06:49)moolight0551 Wrote: Is there a schematic online of the Tx2.4 board. I can only see the later versions.I will add it soon.
(08-04-2016, 06:49)moolight0551 Wrote: I can see the 9V if I connect a multimeter between the DC ground and the 9V pin on the Tx module connector but have difficulty in getting a stable reading if I connect the multimeter between the RF_Tx Gnd connector and the RF_Tx 9V pin.
The power pulse is brief, so it may be difficult to get a reading with a multimeter, but at least you know that the TX module is being powered when required.