mbed API for Raspberry Pi boards.

mbedPi

This is an attempt to implement a limited number of mbed APIs for Raspberry Pi single-board computers. The project was inspired by and based on the arduPi library developed for the Arduino by Cooking Hacks .

/media/uploads/hudakz/board01.jpg

Specifications

  • Chip: Broadcom BCM2836 SoC
  • Core architecture: Quad-core ARM Cortex-A7
  • CPU frequency: 900 MHz
  • GPU: Dual Core VideoCore IV® Multimedia Co-Processor
  • Memory: 1GB LPDDR2
  • Operating System: Boots from Micro SD card, running a version of the Linux operating system
  • Power: Micro USB socket 5V, 2A

Connectors

  • Ethernet: 10/100 BaseT Ethernet socket
  • Video Output: HDMI (rev 1.3 & 1.4)
  • Audio Output: 3.5mm jack, HDMI
  • USB: 4 x USB 2.0 Connector
  • GPIO Connector: 40-pin 2.54 mm (100 mil) expansion header: 2x20 strip providing 27 GPIO pins as well as +3.3 V, +5 V and GND supply lines
  • Camera Connector: 15-pin MIPI Camera Serial Interface (CSI-2)
  • JTAG: Not populated
  • Display Connector: Display Serial Interface (DSI) 15 way flat flex cable connector with two data lanes and a clock lane
  • Memory Card Slot: Micro SDIO

GPIO connector pinout

Zoom in /media/uploads/hudakz/mbedpi_pinout02.png

Information

Only the labels printed in blue/white or green/white (i.e. p3, gpio2 ...) must be used in your code. The other labels are given as information (alternate-functions, power pins, ...).


Building programs for the Raspberry Pi with mbedPi

I use Qt Creator for development, however you can use any other IDE available on the Raspberry Pi (e.g. Geany) if you like. For a quick try:

  • Install Qt and the Qt Creator onto your Raspberry Pi. Then create a new "Blinky" Plain non-Qt C++ Project as follows: /media/uploads/hudakz/newproject.png

  • Change the main code as below:

main.cpp

#include "mbedPi.h"

int main()
{
    DigitalOut  myled(p7);

    while(1) {
        myled = 1; // LED is ON
        wait(0.2); // 200 ms
        myled = 0; // LED is OFF
        wait(1.0); // 1 sec
        printf("Blink\r\n");
    }
}


  • Copy the mbedPi.zip file into your project's folder and unzip.
  • Add the mbedPi.h and mbedPi.cpp files to your project by right clicking on the "Blinky" project and then clicking on the "Add Existing Files..." option in the local menu:

    /media/uploads/hudakz/addfiles.png

    /media/uploads/hudakz/addfiles02.png

  • Double click on Blinky.pro to open it for editing and add new libraries by inserting a new line as follows:

    /media/uploads/hudakz/libs.png

  • Compile the project.

  • Connect an LED through a 1k resistor to pin 7 and the ground on the Raspberry Pi GPIO connector.

  • Run the binary as sudo (sudo ./Blinky) and you should see the LED blinking. /media/uploads/hudakz/mbedpi_run.png

  • Press Ctrl+c to stop running the application.
Committer:
hudakz
Date:
Tue Dec 20 12:16:18 2022 +0000
Revision:
2:131555dc6fb7
Parent:
rpi_wizard/qbs_rpi/RpiApplication.qbs@1:1f2d9982fa8c
Mbed API for Raspberry Pi boards equipped with BCM2836 SoC.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 1:1f2d9982fa8c 1 import qbs
hudakz 1:1f2d9982fa8c 2 import qbs.Process
hudakz 1:1f2d9982fa8c 3 import qbs.File
hudakz 1:1f2d9982fa8c 4 import qbs.FileInfo
hudakz 1:1f2d9982fa8c 5 import qbs.TextFile
hudakz 1:1f2d9982fa8c 6 import "/home/zoli/.config/QtProject/qtcreator/templates/wizards/qbs_rpi/js/helpers.js" as helpers
hudakz 1:1f2d9982fa8c 7
hudakz 1:1f2d9982fa8c 8 CppApplication {
hudakz 1:1f2d9982fa8c 9 type: "application"
hudakz 1:1f2d9982fa8c 10 consoleApplication: true
hudakz 1:1f2d9982fa8c 11 Depends { name: "cpp" }
hudakz 1:1f2d9982fa8c 12 // cpp.cppFlags: "-std=c++11"
hudakz 1:1f2d9982fa8c 13 // Depends {
hudakz 1:1f2d9982fa8c 14 // name: "Qt";
hudakz 1:1f2d9982fa8c 15 // submodules: ["core", "gui", "widgets"]
hudakz 1:1f2d9982fa8c 16 // }
hudakz 1:1f2d9982fa8c 17
hudakz 1:1f2d9982fa8c 18 Group {
hudakz 1:1f2d9982fa8c 19 fileTagsFilter: product.type
hudakz 1:1f2d9982fa8c 20 qbs.install: true
hudakz 1:1f2d9982fa8c 21 qbs.installDir: "bin"
hudakz 1:1f2d9982fa8c 22 qbs.installPrefix: "/mnt/workbench"
hudakz 1:1f2d9982fa8c 23 }
hudakz 1:1f2d9982fa8c 24
hudakz 1:1f2d9982fa8c 25 property string sysPath: "/home/zoli/src/rpi/sys"
hudakz 1:1f2d9982fa8c 26 property stringList sys: [
hudakz 1:1f2d9982fa8c 27 "drivers",
hudakz 1:1f2d9982fa8c 28 ]
hudakz 1:1f2d9982fa8c 29 property pathList sysPaths: {
hudakz 1:1f2d9982fa8c 30 var l = []
hudakz 1:1f2d9982fa8c 31 for (var i = 0; i < sys.length; i++) {
hudakz 1:1f2d9982fa8c 32 l = l.concat(helpers.dirs(sysPath+"/"+sys[i]))
hudakz 1:1f2d9982fa8c 33 }
hudakz 1:1f2d9982fa8c 34 return l
hudakz 1:1f2d9982fa8c 35 }
hudakz 1:1f2d9982fa8c 36
hudakz 1:1f2d9982fa8c 37 Group {
hudakz 1:1f2d9982fa8c 38 name: "sys"
hudakz 1:1f2d9982fa8c 39 condition: (sysPath != "")
hudakz 1:1f2d9982fa8c 40 files: {
hudakz 1:1f2d9982fa8c 41 var l = []
hudakz 1:1f2d9982fa8c 42 for (var i = 0; i < sys.length; i++) {
hudakz 1:1f2d9982fa8c 43 // l = l.concat(sys[i]+"/**")
hudakz 1:1f2d9982fa8c 44 l = l.concat(sys[i]+"/**/*.cpp")
hudakz 1:1f2d9982fa8c 45 l = l.concat(sys[i]+"/**/*.c")
hudakz 1:1f2d9982fa8c 46 l = l.concat(sys[i]+"/**/*.hpp")
hudakz 1:1f2d9982fa8c 47 l = l.concat(sys[i]+"/**/*.h")
hudakz 1:1f2d9982fa8c 48 l = l.concat(sys[i]+"/**/*.s")
hudakz 1:1f2d9982fa8c 49 }
hudakz 1:1f2d9982fa8c 50 return l
hudakz 1:1f2d9982fa8c 51 }
hudakz 1:1f2d9982fa8c 52 prefix: sysPath + "/"
hudakz 1:1f2d9982fa8c 53 }
hudakz 1:1f2d9982fa8c 54
hudakz 1:1f2d9982fa8c 55 property string libPath: "/home/zoli/src/rpi/lib"
hudakz 1:1f2d9982fa8c 56 property stringList libs: []
hudakz 1:1f2d9982fa8c 57 property pathList libPaths: {
hudakz 1:1f2d9982fa8c 58 var l = []
hudakz 1:1f2d9982fa8c 59 for (var i = 0; i < libs.length; i++) {
hudakz 1:1f2d9982fa8c 60 l = l.concat(helpers.dirs(libPath+"/"+libs[i]))
hudakz 1:1f2d9982fa8c 61 }
hudakz 1:1f2d9982fa8c 62 return l
hudakz 1:1f2d9982fa8c 63 }
hudakz 1:1f2d9982fa8c 64
hudakz 1:1f2d9982fa8c 65 Group {
hudakz 1:1f2d9982fa8c 66 name: "libs"
hudakz 1:1f2d9982fa8c 67 condition: (libPath != "")
hudakz 1:1f2d9982fa8c 68 files: {
hudakz 1:1f2d9982fa8c 69 var l = []
hudakz 1:1f2d9982fa8c 70 for (var i = 0; i < libs.length; i++) {
hudakz 1:1f2d9982fa8c 71 // l = l.concat(libs[i]+"/**")
hudakz 1:1f2d9982fa8c 72 l = l.concat(libs[i]+"/**/*.cpp")
hudakz 1:1f2d9982fa8c 73 l = l.concat(libs[i]+"/**/*.c")
hudakz 1:1f2d9982fa8c 74 l = l.concat(libs[i]+"/**/*.hpp")
hudakz 1:1f2d9982fa8c 75 l = l.concat(libs[i]+"/**/*.h")
hudakz 1:1f2d9982fa8c 76 l = l.concat(libs[i]+"/**/*.s")
hudakz 1:1f2d9982fa8c 77 }
hudakz 1:1f2d9982fa8c 78 return l
hudakz 1:1f2d9982fa8c 79 }
hudakz 1:1f2d9982fa8c 80 prefix: libPath + "/"
hudakz 1:1f2d9982fa8c 81 }
hudakz 1:1f2d9982fa8c 82
hudakz 1:1f2d9982fa8c 83 property pathList includePaths: ""
hudakz 1:1f2d9982fa8c 84
hudakz 1:1f2d9982fa8c 85 cpp.compilerIncludePaths: "/home/zoli/toolchain/rpi/arm-bcm2708/arm-bcm2708-linux-gnueabi/arm-bcm2708-linux-gnueabi/include/c++/4.7.1"
hudakz 1:1f2d9982fa8c 86 cpp.compilerFrameworkPaths: "/home/zoli/toolchain/rpi/arm-bcm2708/arm-bcm2708-linux-gnueabi/bin/"
hudakz 1:1f2d9982fa8c 87 cpp.compilerLibraryPaths: "/home/zoli/toolchain/rpi/arm-bcm2708/arm-bcm2708-linux-gnueabi/arm-bcm2708-linux-gnueabi/lib"
hudakz 1:1f2d9982fa8c 88 cpp.includePaths: includePaths.concat("/.", sysPaths, libPath)
hudakz 1:1f2d9982fa8c 89 //cpp.staticLibraries: ["mbed"]
hudakz 1:1f2d9982fa8c 90 cpp.dynamicLibraries: ["rt", "pthread"]
hudakz 1:1f2d9982fa8c 91 }
hudakz 1:1f2d9982fa8c 92
hudakz 1:1f2d9982fa8c 93