RCTimer Voltage / Current Sensor to Hobbyking Pro V2 control

[scatterbrain]

I've searched high and low on these different posts to find an answer to my problem with no luck.

Most posts discussing setting up a voltage / current sensor either focus on the resistors used in the voltage divider or on the parameters needed in the config.h file.

I'm one step behind all of those! All solutions (whether using an RCTimer sensor or home made voltage divider) discuss attaching to the Analog input A1, A2 and ground. But as far as I can see the Hobbyking MultiWii Pro Flight controller ( http://www.hobbyking.com/hobbyking/stor ... odule.html ) seems to be based on a Version 2 MultiWii pro board and doesnt have any A0-5 pins or solder points!

So the obvious question is how do I connect the RCTimer Voltage and Current sensor ( http://www.rctimer.com/index.php?gOo=go ... oductname= ) to the board? Or have I gone down the wrong path and is there an easier way to get the voltage and current readings into the controller rather than use the RCTimer's solution?

I should point out that I'm using an Minim OSD which is working beautifully except for the voltage and current readings!

Any instructions, posts, references would be helpful.

[scatterbrain]

Nobody? Anybody?

Surely there must be some users out there that have used a MultiWii Pro controller boards like the Hobbyking MultiWii Pro board ( http://www.hobbyking.com/hobbyking/stor ... odule.html ). I think the same problem exists for any of the MultiWii pro boards without an A0-A5 pin or solder point (all version 2 boards).

What really surprises me is that (IMHO) the Volt/Amp readout is probably one of the most important readings for a multicopter FPV setup, so surely there must be a easy way to get that data into the controller board and ultimately out to the Minim OSD?

How have other people done it?

[scatterbrain]

Here is a link to a simplified schematic - http://www.hobbyking.com/hobbyking/stor ... 575X22.pdf
and here is a link to a document to setup Megapirates firmware but includes good photos of front and back of board - http://www.hobbyking.com/hobbyking/stor ... 575X22.pdf

[alyeomans]

I know this is an old thread and you to have likely resolved this but to answer you question as I was in a similar situation and others might like to know.

There is no way I know about negating having to solder onto the ADC input pins. You mentioned the home made resistor divider method - this is the same as employed by the Rctimer Voltage & Current sensor module - they claim precision resistors but as 1% tolerance surface mount resistors are small and cheap the home made method is certainly viable. Either way you still need to solder the divided output to one of the ADC input pins.

Home made current sense is trickier as it would probably require a PCB with op amp and resistors - by far more work than the cost of $13 for the RCTimer module.

The MinimOSD can also have the voltage and current sense but there are no connectors so you'd need to solder directly onto the MCU pins.

I'm not sure about the ADC input tolerance but just be careful not to exceed the chip VCC (3.3V or 5V).

Al

[jonathancalderon]

can anyone explain to me how can this be done?
it seems strange....
when i flash the board with Megapirate and try to arm i get a low voltage warning... so i define the minimum voltage on the software lower so the board would arm.
if MegaPirate gets a reading on board voltage why cant we just use that as the voltage sensor ?

please try and help with this... would love to come back to Multiwii firmware

thanks.
Jonathan