Voltage reading from TM1000 telemetry is wrong

P

paulreilly

Member
(Sorry I can't find a more appropriate forum for this question)

I'm using a TM1000 for telemetry on a WKM-based hexcopter, with a Spektrum DX8 on the ground. Power is a pair of 5AH, 4S lipos.

The voltage reading that shows on the DX8 is low by about 0.4V (compared with the battery voltage monitors, or a digital voltmeter straight across the battery). It's low whether the helicopter is flying or idle, so it's not a 'on-load' issue.

I can't find any way to adjust the reading, either at the TM1000 end or the Spektrum end. The only adjustment I can make is to the DX8 alarm threshold.

Can I fix this? Yes, I know I could adjust the alarm and live with it, but it makes the live telemetry pretty useless, and I've already got quite enough confusion, trying to remember that 'Voltage monitor 2 reads 0.2V high', etc.

For what it's worth, if I connect DJI Assistant on the PC to the aircraft, its Voltage screen gets the voltage reading spot on.
 

T

tikigod19

Member
I have exactly the same problem . Learned to live with an adjusted alarm point but like you say, it's not the way it should be.
 

E

Electro 2

Member
Interesting, I've never checked it. I will now, be nice to know. If it was too high, you could deal with it easily, divider, series diode, whatever, but too low is another issue.
 

E

Electro 2

Member
All right, I just went out front and knocked back 3 packs to check some other stuff and tested it. Against a NBS traceable, calibrated, DMM, it's off by 168 mV. It, (the TM), shows the voltage as lower than it actually is. I originally adjusted the alarm empirically, anyway, so I'm OK with the present setting.
 

You must log in or register to reply here.
Top