kalle123 wrote:It might be a stupid question, but let me (retired mechanical engineer
) put it here.
Yesterday evening did a short bench test with openxsensor. MS5611, arduino uno, D4R-II. See pic. Works!
But there are unused analog ports. So why not monitor the Lipo cell voltages. First cell on A0 (should be OK directly 4.2 V max.)
Second cell with voltage divider (2x 2k) on A1. But what am I doing with that? I am bringing with that divider the
SUM of cell 1+2 to a level < 5 volts and monitoring that on A1. Aim was to monitor
only cell 2.
Where am I wrong?
br
openxsensor (OXS) can be configured in order to read several voltage (up to 6).
Each of them are measured using the same ground.
So if you use a multicell lipo, OXS can read the first cell( as voltage1), the sum of cell 1 and 2 (as voltage 2), the sum of cell 1 + 2 + 3 (as voltage 3), ...
You know already that it requires some voltage divider in order to bring some voltage down.
Once those measurements are done, OXS allows you to select which information have to be sent to the Tx.
You can transmit each voltage but then you do not get the voltage of each cell indivudually.
You can also ask OXS to send the voltage of each cell individually using the foreseen setup.
To do so, you have to :
- specify the max number of cells in the line: #define NUMBEROFCELLS 3 (here 3 is the max number of cells you are measuring using voltage 1, 2 and 3)
- specify that OXS has to calculate and send each cell using those lines:
DEFAULTFIELD , CELLS_1_2 , 1 , 1 ,0 , \
DEFAULTFIELD , CELLS_3_4 , 1 , 1 ,0 , \
DEFAULTFIELD , CELLS_5_6 , 1 , 1 ,0 , \
Note: remove the lines regarding cells in excess (e.g. if you have only 3 cells, remove the line regarding CELLS_5_6)
When Tx will receive the voltage of each cell, it can display all of them on a special telemetry panel (see openTx manual) and it can display on any user configurable display the lowest voltage cell (using CELL) and the total (using CELLS)
)
)