MUPilot Flight Controller¶
The MUPilot flight controller is sold by MUGIN UAV
Features¶
STM32F765 Microcontroller
STM32F103 IOMCU
Three IMUs: ICM20689, MPU6000 and BMI055
Internal vibration isolation for IMUs
Two MS5611 SPI barometers
IST8310 magnetometer
MicroSD card slot
6 UARTs plus USB
14 PWM outputs with selectable 5V or 3.3V output voltage
Four I2C and two CAN ports
External Buzzer
builtin RGB LED
external safety Switch
voltage monitoring for servo rail and Vcc
two dedicated power input ports for external power bricks
Mechanical¶
91mm x 46mm x 31mm
106g
Connectors¶
CAN1/2
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
CAN_H |
+3.3V |
3 |
CAN_L |
+3.3V |
4 |
GND |
GND |
GPS&SAFETY
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
UART_TX1 |
+3.3V |
3 |
UART_RX1 |
+3.3V |
4 |
I2C1_SCL |
+3.3V |
5 |
I2C1_SDA |
+3.3V |
6 |
SAFETY_SW |
+3.3V |
7 |
SAFETY_SW_LED |
+3.3V |
8 |
3V3_OUT |
+3.3V |
9 |
BUZZER |
+3.3V |
10 |
GND |
GND |
I2C1/2/3/4
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
I2Cx_SCL |
+3.3V |
3 |
I2Cx _SDA |
+3.3V |
4 |
GND |
GND |
TELEM1
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
UART_TX2 |
+3.3V |
3 |
UART_RX2 |
+3.3V |
4 |
CTS |
+3.3V |
5 |
RTS |
+3.3V |
6 |
GND |
GND |
TELEM2
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
UART_TX6 |
+3.3V |
3 |
UART_RX6 |
+3.3V |
4 |
CTS |
+3.3V |
5 |
RTS |
+3.3V |
6 |
GND |
GND |
UART4(GPS2)
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
UART_TX3 |
+3.3V |
3 |
UART_RX3 |
+3.3V |
4 |
I2C2_SCL |
+3.3V |
5 |
I2C2_SDA |
+3.3V |
6 |
GND |
GND |
DEBUG
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
UART_TX7 |
+3.3V |
3 |
UART_RX7 |
+3.3V |
4 |
SWDIO |
+3.3V |
5 |
SWCLK |
+3.3V |
6 |
GND |
GND |
POWER1
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC_IN |
+5V |
2 |
VCC_IN |
+5V |
3 |
CURRENT_ADC |
+3.3V |
4 |
VOLTAGE_ADC |
+3.3V |
5 |
GND |
GND |
6 |
GND |
GND |
POWER2
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC_IN |
+5V |
2 |
VCC_IN |
+5V |
3 |
CURRENT_ADC/I2C1_SCL |
+3.3V |
4 |
VOLTAGE_ADC/I2C1_SDA |
+3.3V |
5 |
GND |
GND |
6 |
GND |
GND |
SBUS OUT
Pin |
Signal |
Volt |
|---|---|---|
1 |
||
2 |
SBUS OUT |
+3.3V |
3 |
GND |
GND |
ADC
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
ADC_3V3 |
+3.3V |
3 |
ADC_6V6 |
+6.6V |
4 |
GND |
GND |
SPI5
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
SCK |
+3.3V |
3 |
MISO |
+3.3V |
5 |
MOSI |
+3.3V |
6 |
CS1 |
+3.3V |
7 |
CS2 |
+3.3V |
8 |
GND |
GND |
DSM/SBUS/RSSI
Pin |
Signal |
Volt |
|---|---|---|
1 |
VCC |
+5V |
2 |
DSM/SBUS |
+3.3V |
3 |
RSSI |
+3.3V |
4 |
3V3_OUT |
+3.3V |
5 |
GND |
GND |
UART Mapping¶
SERIAL0 -> USB
SERIAL1 -> UART2 (Telem1)
SERIAL2 -> UART3 (Telem2)
SERIAL3 -> UART1 (GPS)
SERIAL4 -> UART4 (GPS2)
SERIAL5 -> UART6 (spare)
SERIAL6 -> UART7 (spare, debug)
SERIAL7 -> USB2 (SLCAN)
The Telem1 and Telem2 ports have RTS/CTS pins, the other UARTs do not have RTS/CTS.
The UART7 connector is labeled debug, but is available as a general purpose UART with ArduPilot.
RC Input¶
RC input is configured on the PPM pin, at one end of the servo rail, marked RC in the above diagram. This pin supports all unidirectional RC protocols including PPM. The DSM/SBUS pin is also tied to the PPM pin. For CRSF/ELRS/etc. protocols, a full UART will need to be used with its SERIALx_PROTOCOL set to “23”.
PWM Output¶
The MUPilot supports up to 14 PWM outputs. First first 8 outputs (labeled “M1 to M8”) are controlled by a dedicated STM32F103 IO controller. These 8 outputs support all PWM output formats, but not DShot.
The remaining 6 outputs (labeled A1 to A6) are the “auxiliary” outputs. These are directly attached to the STM32F765 and support all PWM protocols as well as DShot.
All 14 PWM outputs have GND on the top row, 5V on the middle row and signal on the bottom row.
The 8 main PWM outputs are in 3 groups:
PWM 1 and 2 in group1
PWM 3 and 4 in group2
PWM 5, 6, 7 and 8 in group3
The 6 auxiliary PWM outputs are in 2 groups:
PWM 1, 2, 3 and 4 in group1
PWM 5 and 6 in group2
Channels within the same group need to use the same output rate. If any channel in a group uses DShot then all channels in the group need to use DShot.
The output levels of the auxiliary outputs can be selected by switch to be either 3.3V or 5V. The output level is 3.3V for the main outputs.
Battery Monitoring¶
The board has two dedicated power monitor ports on 6 pin connectors. The correct battery setting parameters are dependent on the type of power brick which is connected. The first is analog only, the second may be either analog or I2C, depending on baseboard jumpers.
In order to enable monitoring, the BATT_MONITOR or BATT2_MONITOR parameter must be set. By default BATT_MONITOR is set to “4” for the included power module..
Default params for the first monitor are set and are: * BATT_VOLT_PIN = 2 * BATT_CURR_PIN = 1 * BATT_VOLT_MULT = 18.0 * BATT_AMP_PERVLT = 24.0 (may need adjustment if supplied monitor is not used)
Compass¶
The MUPilot has a builtin IST8310 compass. Due to potential interference the board is usually used with an external I2C compass as part of a GPS/Compass combination.
GPIOs¶
The 6 auxiliary outputs can be used as GPIOs (relays, buttons, RPM etc). To use them see GPIOs
The numbering of the GPIOs for PIN variables in ArduPilot is: * MAIN1 101 * MAIN2 102 * MAIN3 103 * MAIN4 104 * MAIN5 105 * MAIN6 106 * MAIN7 107 * MAIN8 108 * AUX1 50 * AUX2 51 * AUX3 52 * AUX4 53 * AUX5 54 * AUX6 55
Analog inputs¶
The MUPilot has 7 analog inputs * ADC Pin0 -> Battery Voltage * ADC Pin1 -> Battery Current Sensor * ADC Pin2 -> Battery Voltage 2 * ADC Pin3 -> Battery Current Sensor 2 * ADC Pin4 -> ADC port pin 2 * ADC Pin14 -> ADC port pin 3 * ADC Pin10 -> Board 5V Sense * ADC Pin11 -> Board 3.3V Sense * ADC Pin103 -> RSSI voltage monitoring
Loading Firmware¶
The board comes pre-installed with an ArduPilot compatible bootloader, allowing the loading of *.apj firmware files with any ArduPilot compatible ground station.