Extra addon-decks & sensors
Add-on decks from Bitcraze AB
The Flapper is compatible with some of the add-on decks designed for Crazyflie 2.0/2.1 by Bitcraze AB. Please consult our deck compatibility overview.
When installing add-on decks by stacking them directly on top of the Flapper's PCB, pay attention to its correct orientation, which depends on the model year of your Flapper!
An example of the “Loco positioning deck” orientation after installation is below on the right, for model years newer than 2022 the 2022 photo applies:
For decks requiring horizontal installation (e.g. Lighthouse), you can also use an extension cable and place the decks to the top/bottom of the Flapper. For some of the decks, you can find 3d-printable stl files here. Instructions on how to make the extension cable are included here, we can also supply a beta version of an extension cable upon request.
Custom add-ons
If you plan to add your own sensors/decks, please see the table and pinout schematics below and refer to the datasheet of the Crazyflie Bolt. Please note that some of the pins are already in use. The pins marked with an asterix* are in use with the default firmware but can be freed up by disabling the respective functionality in the firmware.
| Left Connector | Right Connector | |||||
|---|---|---|---|---|---|---|
| Pin | Name | Remark | Pin | Name | Remark | |
| 1 | VCC | 3V, max 100mA | 1 | TX2 | ADC for current measurement (only on revD and newer) | |
| 2 | RX1 | available | 2 | RX2 | CPPM (ext. Rx), used only if enabled in the firmware | |
| 3 | TX1 | available | 3 | SCK | available | |
| 4 | SDA | available | 4 | MISO | available | |
| 5 | SCL | available | 5 | MOSI | available | |
| 6 | IO_1 | available | 6 | N_IO_1 | available | |
| 7 | IO_2 | RGB LEDs* | 7 | N_IO_2 | available | |
| 8 | IO_3 | RGB LEDs* | 8 | WKUP | OW deck memory | |
| 9 | IO_4 | uSD card* | 9 | VCOM | 5V, max. 400mA | |
| 10 | GND | STM ground | 10 | VUSB | ||
The Flapper Drone PCB has two grounds which are NOT inter-connected (2S LiPo and STM). The ground marked by black squares connects to the 2S battery and is switchable. With the standard Flapper firmware, this ground gets disconnected when you power off the Bolt using its power button. This disconnects the ESCs and servomotors from power, so the battery discharge rate in this state is very low. Still, for storage always disconnect the battery.
If you plan to add additional devices, which you'd like to power from the 2S battery, and which need to be connected also to the STM of the Bolt (e.g. an external receiver), always place a ~1k resistor between the GPIO and your device to protect the GPIO. Otherwise, because the 2S ground on the board is switchable, when powered down with the switch on the Bolt the 2S voltage will get to the GPIO, which will likely get damaged as a result.
For model 2021, this applies also to the WS2812B/WS2813 RGB LEDs, use a 1k resistor to protect the GPIO!
From model 2022 (revD), the pads for WS2812B RGB LEDs and for CPPM are already protected.
Alternatively, consider using VCC/V-USB available from the Bolt and the STM ground on the left side connector (but check the power limitations of the Bolt board first).
Model 2021 - PAY ATTENTION: Due to a manufacturing issue, the ground marked with “READ MANUAL” should only be used if absolutely necessary, and extreme caution needs to be taken when soldering. When finished soldering double check that the 2S ground is still disconnected from the GND on the side connector (and the uSD card slot housing). If that happens, try to remove any excess solder and double check. Contact our support if needed.
We recommend using another square-marked ground instead.