Hello, I recently purchased a kakute f7 mini v2 to use with arduplane. I have been struggling to get my current reading accurate. I have heard conflicting information about if the kakute f7 mini v2 has a built in current sensor. The manual makes it sound like it does, but it doesn’t have a built in pdb. So my first question is does it have a built in current sensor? I want to use a external current sensor and need to know what value to set the
BATT_CURR_PIN parameter in arduplane to. In other words I need to know what analog input pin the current sensor is set too.
the board doesn’t have a current sensor in terms of an onboard shunt type resistor connected to an adc, but it does have an adc input that defaults to batt mon current pin (pin 12 in runtime) and can be used to connect an external sensor / PDB. the divider defaults to 28.5 as per hwdef default. what value you need depends on your current sensor hardware, best check that hardware’s specs for advice.
most likely you’ll want to set BATT_MON parameter to 4 (voltage + current), check the readings and, if required, calibrate current following the existent documentation’s advice:
hmm this is where I have gotten stuck. I am using it in combination with the radix li wing pdb which has a current sensor. I have them correctly wired together, set to 4. The current sensor on the radix is listed as 50mv/a and so I have entered 20 into the divider. However this value produces massively inaccurate values. So using a clamp meter I followed the calibration instructions but was completely unable to get a value that generated accurate values for all current draws. So, at that point it was when I decided that analog input must be mapped to something else, hence the erratic behavior.
a quick google lookup shows various versions of the radix PDB, including one with a 50mV/A sensor too. might depend on what actual type you got.
if you do get readings that roughly correlate with current draw, even if somewhat off, you likely set up the wiring correctly. i might help to show your exact PDB type, your wiring, plus a log of what readings you get. providing a log will allow looking at your current param settings too.
Sorry I misspoke. I have the radix li wing pdb, which the current sensor is 50mv/a. The readings do go up with a increase in throttle, but exponentially. I have used a clamp meter and run multiple current draw calibrations trying to get the A/V param tuned in, however it seems impossible to find a value that accurately calculates all current draws. So lets say I set throttle to 100%, I enter measured current as 6.9a, the A/V jumps from 20 to 40ish, and calculated current changes to 6.9a. The problem is that then when I set my throttle to 50% measured current is 2.5a, the calculated current is like 1a. I have the same problem in reverse if I run the calibration at 50% throttle.