B0B is ready!
B0B is a very simple way to fly your Mavic Mini without the DJI genuine battery but with the telemetry of voltage available on the RC.
Obviously there is some electronics behind this.
A PIC12F1840 microcontroler will emulate the I2C traffic needed by the ESC board of the Mavic mini to start the drone and to collect telemetry information.
The voltage of the cells is acquired by B0B via a resistor bridge.
The total voltage of the batt is displayed into the Mavic Mini temperature field. This is done on purpose just to remember you flight with B0B and not genuine battery.
The voltage is displayed like this :
820,0 °C ==> means 8,200 V
This value is then divided by 2 and displayed into each cell gauge.
The battery remaining capacity is estimated based on the total voltage and displayed on the screen. The estimation is NOT accurate and is clamped to a minimum value around 11%. Just enough to trigger the low batt warning
;-)
You'll have to flight "with tension" reading the total voltage of the batt. Don't go under 6.6V or the batt can be damaged (and the drone may lose power and eventually crash)
To be clear, as its name means B0B is a battery with no BMS.
You cannot use it to charge the batt from the DJI charger nor from the USB plug from the drone.
B0B is "stupid". it just fools the DJI firmware giving it just enough information to start the drone and display voltage . That is !
The battery is attached to B0B with a "sliding" 2x3pins connector. You can use a single B0B and own as many batteries you like. Two Samsung 2400mAh 18650 cells can be found for 10€ on ebay
;-)
the battery can be un attached and I charge it using the same connector to attach it + the middle point to balance it...
Only very few components are needed:
The battery type inside the firmware shall be set to type 2 or 3 (which means just a warning on the screen in case of low batt and no RTH. (you are just warned)
Should you want to keep the advantages of the latest firmware for the manual setting in video, there is the solution of "firmware module mixing"
;-)
BTW, why placing it on thingiverse? just because there is a 3D printed lock mechanism to avoid a disconnection of the batt ...
www.thingiverse.com
Of course the door can be closed and the batt is lighter than the genuine one (5 grams shaved in the mass budget)!
Should you be interested to build one, just PM me.. I get 8 spare PCBs and microcontrollers available
B0B is a very simple way to fly your Mavic Mini without the DJI genuine battery but with the telemetry of voltage available on the RC.
Obviously there is some electronics behind this.
A PIC12F1840 microcontroler will emulate the I2C traffic needed by the ESC board of the Mavic mini to start the drone and to collect telemetry information.
The voltage of the cells is acquired by B0B via a resistor bridge.
The total voltage of the batt is displayed into the Mavic Mini temperature field. This is done on purpose just to remember you flight with B0B and not genuine battery.
The voltage is displayed like this :
820,0 °C ==> means 8,200 V
This value is then divided by 2 and displayed into each cell gauge.
The battery remaining capacity is estimated based on the total voltage and displayed on the screen. The estimation is NOT accurate and is clamped to a minimum value around 11%. Just enough to trigger the low batt warning
You'll have to flight "with tension" reading the total voltage of the batt. Don't go under 6.6V or the batt can be damaged (and the drone may lose power and eventually crash)
To be clear, as its name means B0B is a battery with no BMS.
You cannot use it to charge the batt from the DJI charger nor from the USB plug from the drone.
B0B is "stupid". it just fools the DJI firmware giving it just enough information to start the drone and display voltage . That is !
The battery is attached to B0B with a "sliding" 2x3pins connector. You can use a single B0B and own as many batteries you like. Two Samsung 2400mAh 18650 cells can be found for 10€ on ebay
the battery can be un attached and I charge it using the same connector to attach it + the middle point to balance it...
Only very few components are needed:
- a PIC 12F1840 with a dedicated firmware
- 2 resistors (1k and 1,8k)
- a 3.3 LDO HT733 voltage regulator
- a small capacitor
- a battery connector
- a PCB
- 6 pins from a 2.54 pins connector
- a 8 pins 2,54 female connector (to be installed on the battery)
The battery type inside the firmware shall be set to type 2 or 3 (which means just a warning on the screen in case of low batt and no RTH. (you are just warned)
Should you want to keep the advantages of the latest firmware for the manual setting in video, there is the solution of "firmware module mixing"
BTW, why placing it on thingiverse? just because there is a 3D printed lock mechanism to avoid a disconnection of the batt ...
Mavic Mini : B0B (fly any Battery with no BMS) by aeropic
B0B is a very simple way to fly your Mavic Mini without the DJI genuine battery but with the telemetry of voltage available on the RC. B0B is not a battery, it's rather a cheap platform to experiment with any battery you wish. B0B is able to communicate with the ESC board of the drone giving it...
www.thingiverse.com
Should you be interested to build one, just PM me.. I get 8 spare PCBs and microcontrollers available
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