I have a strange “problem” with VE.Direct connector on my Victron 100/30 MPPT charge controller.
I’m trying to monitor my mppt controller with an Atom S3 lite (esp32) and home assistant integration via VE.Direct. TX (pin 2) and RX (pin 3) pins work as they should and I’m getting data into home assistant. So far so good
Voltage between pins 1 (ground) and 4 (VCC) should be +5V so I should also be able to provide power to Atom S3 directly through these two pins.
I’ve measured the voltage across these two pins and I keep getting 8.8-9.0 volts! I’ve done a basic google search but found nothing useful. What am I missing - is there a setting somewhere in Victron Connect to address this issue?
FWIK, that voltage between the pins 1 and 4 of the connector is the voltage obtained through an isolated DC-DC converter.
Depending on the voltmeter you used, this could be influenced by the high frequency chopping of the DC-DC converter and show you a much greater voltage. Not to mention that the capacitors used for smoothing out this PWM pulses are too small in my opinion.
Use a 1K resistor in parallel with the voltmeter probes and see if it’s still 9V.
But yes, the voltage there should be, generally speaking and on newer devices, 3.3V.
Only oooold devices could present there 5V.
I would disconnect everything from the VE-direct port and try measuring again.
I think that the dc voltage available here is derived from the internal processors 5 or 3.3v supply, so as not to cause the processor problems. It is designed only to power a digital isolator chip.
If you are getting problems, you should consider inserting a digital isolator between the MPPT and the home assistant, and also between the MPPT and the atom.
