ImuCalibration/Gyroscopes

Pictures

• 

  Turntable rig

• 

  IMU cradle view 1.0

• 

  IMU cradle view 1.1

• 

  Encoder mount base

• 

  Olimex LPC H2148

• 

  Omron rotary encoder

Components

• audio-technica AT-LP120_USB Direct Drive Professional Turntable
• Olimex LPC H2148
• Omron rotary encoder
• Lisa/L+IMU, Xbee 2.4Ghz modem set, fibreglass mounting plates and general wiring components

Wiring

Encoder to LPC

• Black (common) to EXT2 GND

• Red 5~12 VDC to EXT2 Vin(5v)

• White OUTA to EXT1 PO.22

LPC to LPC

• EXT2 3.3v to EXT1 PO.22 (pull up resistor)

LPC Code Modifications

In case of USB 2.0 A-B cable operation, ~/conf/airframes/Poine/turntable.xml has to be amended, as follows, and saved as ~/turntable_dev_usb.xml:

File: conf/airframes/Poine/turntable_dev_usb.xml

main.CFLAGS += -DUSE_USB_SERIAL main.srcs += $(SRC_ARCH)/usb_ser_hw.c main.srcs += $(SRC_ARCH)/lpcusb/usbhw_lpc.c $(SRC_ARCH)/lpcusb/usbinit.c main.srcs += $(SRC_ARCH)/lpcusb/usbcontrol.c $(SRC_ARCH)/lpcusb/usbstdreq.c main.CFLAGS += -DDOWNLINK -DDOWNLINK_TRANSPORT=PprzTransport -DDOWNLINK_DEVICE=UsbS #main.CFLAGS += -DUSE_UART0 -DUART0_BAUD=B115200 #main.srcs += mcu_periph/uart.c #main.srcs += $(SRC_ARCH)/mcu_periph/uart_arch.c #main.CFLAGS += -DDOWNLINK -DDOWNLINK_TRANSPORT=PprzTransport -DDOWNLINK_DEVICE=Uart0 main.srcs += subsystems/datalink/downlink.c subsystems/datalink/pprz_transport.c #main.CFLAGS += -DMB_TACHO #main.srcs += $(MB)/mb_tacho.c </makefile> </airframe>

A new turntable session has to be added to ~/conf/control_panel.xml:

File: conf/control_panel.xml

<session name="Flight with USB-serial_TT modem"> <program name="Data Link"> <arg flag="-d" constant="/dev/ttyACM0"/> <arg flag="-nouplink" constant=""/> <arg flag="-s" constant="115200"/> </program> <program name="Server"/> <program name="GCS"/> </session>

Encoder Code Modifications

Line 43 in ~/sw/airborne/firmwares/motor_bench/main_turntable has to be amended to reflect the encoder's factory pulses per revolution (P/R) setting from default "#define NB_STEP 256". The encoder above has a factory resolution set at "300" (P/R).

File: sw/airborne/firmwares/motor_bench/main_turntable.xml

#define NB_STEP 300