Inter-MCU communication over UART

To enable this, please set the "SEPARATE_FBW" configure option to TRUE in your airframe file for both AP and FBW targets

Example for airframe file

Add to your firmware section: This example contains all possible configuration options, not all of them are mandatory!

<module name="intermcu_uart">
  b'<configure name="SEPARATE_FBW" value="FALSE|TRUE" />\n    '
  b'<configure name="INTERMCU_PORT" value="UARTx" />\n    '
  b'<configure name="INTERMCU_BAUD" value="B57600" />\n    '
  b'<configure name="FBW_MODE_LED" value="none|num" />\n  '
</module>

Module configuration options

Configure Options

name: SEPARATE_FBW value: FALSE|TRUE
Description: Enable separation between AP and FBW on separated MCU
name: INTERMCU_PORT value: UARTx
Description: UART used for inter mcu communication (default: UART2 for FBW, UART5 for AP)
name: INTERMCU_BAUD value: B57600
Description: UART baud rate
name: FBW_MODE_LED value: none|num
Description: LED number or 'none'

Module functions

Init Functions

These initialization functions are called once on startup.

intermcu_init()

Periodic Functions

These functions are called periodically at the specified frequency from the module periodic loop.

intermcu_periodic()
- Running at maximum module frequency.
- Autorun: LOCK
  Periodic function automatically starts after init and can't be stopped.

Files

Header Files

The following headers are automatically included in modules.h

Source Files

Raw intermcu_uart.xml file:

<!DOCTYPE module SYSTEM "module.dtd">
 
<module name="intermcu_uart" dir="intermcu" task="core">
  <doc>
    <description>
      Inter-MCU communication over UART
 
      To enable this, please set the "SEPARATE_FBW" configure option to TRUE
      in your airframe file for both AP and FBW targets
    </description>
    <configure name="SEPARATE_FBW" value="FALSE|TRUE" description="Enable separation between AP and FBW on separated MCU"/>
    <configure name="INTERMCU_PORT" value="UARTx" description="UART used for inter mcu communication (default: UART2 for FBW, UART5 for AP)"/>
    <configure name="INTERMCU_BAUD" value="B57600" description="UART baud rate"/>
    <configure name="FBW_MODE_LED" value="none|num" description="LED number or 'none'"/>
  </doc>
 
  <dep>
    <depends>uart</depends>
    <provides>intermcu,commands,radio_control</provides>
  </dep>
  <header>
    <file name="intermcu.h" cond="ROTORCRAFT_FIRMWARE"/>
    <file name="inter_mcu.h" cond="FIXEDWING_FIRMWARE"/>
  </header>
  <init fun="intermcu_init()"/>
  <periodic fun="intermcu_periodic()"/>
  <makefile target="fbw" firmware="fixedwing">
    <configure name="INTERMCU_PORT" default="UART2" case="upper|lower"/>
    <configure name="FBW_MODE_LED" default="none"/>
    <define name="FBW_MODE_LED" value="$(FBW_MODE_LED)" cond="ifneq ($(FBW_MODE_LED),none)"/>
    <define name="INTER_MCU_FBW"/>
  </makefile>
  <makefile target="ap" firmware="fixedwing">
    <configure name="INTERMCU_PORT" default="UART5" case="upper|lower"/>
    <define name="INTER_MCU_AP"/>
  </makefile>
  <makefile target="ap|fbw" firmware="fixedwing">
    <raw>
      ifeq (,$(findstring $(SEPARATE_FBW),1 TRUE))
      $(error Using intermcu via UART, so dual mcu with separate fbw. Please set option "SEPARATE_FBW" to TRUE.
      endif
    </raw>
    <configure name="INTERMCU_BAUD" default="B57600"/>
    <define name="INTERMCU"/>
    <define name="MCU_UART_LINK"/>
    <define name="INTERMCU_LINK" value="$(INTERMCU_PORT_LOWER)"/>
    <define name="USE_$(INTERMCU_PORT_UPPER)"/>
    <define name="$(INTERMCU_PORT_UPPER)_BAUD" value="$(INTERMCU_BAUD)"/>
    <file name="link_mcu_usart.c"/>
  </makefile>
 
  <makefile target="fbw" firmware="rotorcraft">
    <configure name="INTERMCU_PORT" default="UART3" case="upper|lower"/>
    <configure name="FBW_MODE_LED" default="none"/>
    <define name="FBW_MODE_LED" value="$(FBW_MODE_LED)" cond="ifneq ($(FBW_MODE_LED),none)"/>
    <define name="INTER_MCU_FBW"/>
    <define name="DOWNLINK"/>
    <file name="intermcu_fbw.c"/>
  </makefile>
  <makefile target="ap" firmware="rotorcraft">
    <configure name="INTERMCU_PORT" default="UART3" case="upper|lower"/>
    <configure name="RADIO_CONTROL_LED" value="none"/>
    <define name="INTER_MCU_AP"/>
    <define name="RADIO_CONTROL_TYPE_H" value="modules/intermcu/intermcu_ap.h" type="string"/>
    <define name="RADIO_CONTROL"/>
    <define name="RADIO_CONTROL_LED" value="$(RADIO_CONTROL_LED)" cond="ifneq ($(RADIO_CONTROL_LED),none)"/>
    <define name="GPS_SECONDARY_TYPE_H" value="modules/intermcu/intermcu_ap.h" type="string" cond="ifneq (,$(findstring $(SECONDARY_GPS), imcu))"/>
    <define name="SECONDARY_GPS" value="GPS_IMCU" cond="ifneq (,$(findstring $(SECONDARY_GPS), imcu))"/>
    <define name="IMCU_GPS" cond="ifneq (,$(findstring $(SECONDARY_GPS), imcu))"/>
    <file name="intermcu_ap.c"/>
    <file name="radio_control.c" dir="modules/radio_control"/>
  </makefile>
  <makefile target="ap|fbw" firmware="rotorcraft">
    <configure name="INTERMCU_BAUD" default="B230400"/>
    <define name="INTERMCU_LINK" value="$(INTERMCU_PORT_LOWER)"/>
    <define name="USE_$(INTERMCU_PORT_UPPER)"/>
    <define name="$(INTERMCU_PORT_UPPER)_BAUD" value="$(INTERMCU_BAUD)"/>
    <file name="pprz_transport.c" dir="pprzlink/src"/>
  </makefile>
</module>
 