First time poster and newb DIY drone builder. So please pardon my ignorance.
I've sourced parts for a DJI Flamewheel 450 clone. Obviously the FC is the BBBmini, along with the recommended baro, gps, sonar sensors also picked up a genuine 3dr telemetry radio which will be connected via UART. Finally I've ordered a set of Castle Creations DMR 30/40 ESCs.
I'm left with identifying the PDB and motors. I have some used DJI 2212 920KV motors that I may swap out for some EMAX or Multistar 2213 or 2216 motors as I'd like the option of not having to modify props and be able to bump up to a 4s battery and carry heavier loads with 11 or possibly 12 inch props.
Any feedback on the motor is appreciated but not the goal of this post.
I've picked up a Matek HUBOSD8-SE PDB which has a current output for FC sensing. The output is a varied voltage to signify current passing through the PDB.
Will this current sensing method work with the BBBmini and arducopter? I assume I would need to configure this in arducopter if it does?
In this case how do I detect voltage? Does the 20k and 10k resistor on the BBBmini 1.5 board setup a voltage divider for voltage sensing by connecting the voltage input on the BBBmini to the positive battery lead on the PDB?
If this will not work I have another option below.
I also picked up a genuine 3dr power module which based on the recommended hardware for the BBBmini will work. Does the current and voltage sense lines from the power module to the current and voltage sense input lines on the BBBmini also using the 20k / 10k voltage divider?
Thanks for this board and this awesome resource!
Hi Chris and welcome.
Do you know what runs in this ESC DMR ? There are several ESC don't work well on BBBMini - usually the ESC running BLHeli or SimonK works better and some proprietary ESC - for instance - ZTW Beatles doesn't work.
About the power sensing, BBBMini works with 3DR power modules and clones. I don't remember right know the output of voltage and current sensing(if I not wrong is abount 3.3 volts i think), but beaglebone ADC works with 0 to 1.8V so the resistors is a voltage divider. I couldn't find any datasheed of this PDB board, so you need to check the voltage of measurement current to see if fits :)
Here's the link to the ESCs, the datasheet is on the specifications tab. These ESCs run Castle Creations' firmware. Based on my research these are fairly configurable and do some dynamic adjusting on their own. So my thought was that they could be configured to work and or auto adjust to the signal provided by the BBBmini. I've some experience with PWM and timing, perhaps I can break some new ground of compatible ESCs. I willing to take a chance. :)
Below is the link to the PDB, the manual on the Download & Files tab contains info on the current sense voltage which is a 3.3v signal.
If I choose to skip the power module and run with just this PDB, which appears should work for current sensing, is it sufficient to ensure the voltage divider is adequate to drop the 3s or 4s battery voltage below the BBB 3.3v gpio limit and then connect the battery to the voltage sense pin directly?