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:
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 #ifndef _PIN_NAMES_H_
hudakz 1:1f2d9982fa8c 2 #define _PIN_NAMES_H_
hudakz 1:1f2d9982fa8c 3
hudakz 1:1f2d9982fa8c 4 typedef enum {
hudakz 1:1f2d9982fa8c 5 // Not connected
hudakz 1:1f2d9982fa8c 6 NC = (int)0xFFFFFFFF,
hudakz 1:1f2d9982fa8c 7
hudakz 1:1f2d9982fa8c 8 // GPIO names
hudakz 1:1f2d9982fa8c 9 gpio2 = 2,
hudakz 1:1f2d9982fa8c 10 gpio3 = 3,
hudakz 1:1f2d9982fa8c 11 gpio4 = 4,
hudakz 1:1f2d9982fa8c 12 gpio5 = 5,
hudakz 1:1f2d9982fa8c 13 gpio6 = 6,
hudakz 1:1f2d9982fa8c 14 gpio7 = 7,
hudakz 1:1f2d9982fa8c 15 gpio8 = 8,
hudakz 1:1f2d9982fa8c 16 gpio9 = 9,
hudakz 1:1f2d9982fa8c 17 gpio10 = 10,
hudakz 1:1f2d9982fa8c 18 gpio11 = 11,
hudakz 1:1f2d9982fa8c 19 gpio12 = 12,
hudakz 1:1f2d9982fa8c 20 gpio13 = 13,
hudakz 1:1f2d9982fa8c 21 gpio14 = 14,
hudakz 1:1f2d9982fa8c 22 gpio15 = 15,
hudakz 1:1f2d9982fa8c 23 gpio16 = 16,
hudakz 1:1f2d9982fa8c 24 gpio17 = 17,
hudakz 1:1f2d9982fa8c 25 gpio18 = 18,
hudakz 1:1f2d9982fa8c 26 gpio19 = 19,
hudakz 1:1f2d9982fa8c 27 gpio20 = 20,
hudakz 1:1f2d9982fa8c 28 gpio21 = 21,
hudakz 1:1f2d9982fa8c 29 gpio22 = 22,
hudakz 1:1f2d9982fa8c 30 gpio23 = 23,
hudakz 1:1f2d9982fa8c 31 gpio24 = 24,
hudakz 1:1f2d9982fa8c 32 gpio25 = 25,
hudakz 1:1f2d9982fa8c 33 gpio26 = 26,
hudakz 1:1f2d9982fa8c 34 gpio27 = 27,
hudakz 1:1f2d9982fa8c 35
hudakz 1:1f2d9982fa8c 36 // Rapsberry Pi pin names
hudakz 1:1f2d9982fa8c 37 p3 = gpio2,
hudakz 1:1f2d9982fa8c 38 p5 = gpio3,
hudakz 1:1f2d9982fa8c 39 p7 = gpio4,
hudakz 1:1f2d9982fa8c 40 p8 = gpio14,
hudakz 1:1f2d9982fa8c 41 p10 = gpio15,
hudakz 1:1f2d9982fa8c 42 p11 = gpio17,
hudakz 1:1f2d9982fa8c 43 p12 = gpio18,
hudakz 1:1f2d9982fa8c 44 p13 = gpio27,
hudakz 1:1f2d9982fa8c 45 p15 = gpio22,
hudakz 1:1f2d9982fa8c 46 p16 = gpio23,
hudakz 1:1f2d9982fa8c 47 p18 = gpio24,
hudakz 1:1f2d9982fa8c 48 p19 = gpio10,
hudakz 1:1f2d9982fa8c 49 p21 = gpio9,
hudakz 1:1f2d9982fa8c 50 p22 = gpio25,
hudakz 1:1f2d9982fa8c 51 p23 = gpio11,
hudakz 1:1f2d9982fa8c 52 p24 = gpio8,
hudakz 1:1f2d9982fa8c 53 p26 = gpio7,
hudakz 1:1f2d9982fa8c 54 p29 = gpio5,
hudakz 1:1f2d9982fa8c 55 p31 = gpio6,
hudakz 1:1f2d9982fa8c 56 p32 = gpio12,
hudakz 1:1f2d9982fa8c 57 p33 = gpio13,
hudakz 1:1f2d9982fa8c 58 p35 = gpio19,
hudakz 1:1f2d9982fa8c 59 p36 = gpio16,
hudakz 1:1f2d9982fa8c 60 p37 = gpio26,
hudakz 1:1f2d9982fa8c 61 p38 = gpio20,
hudakz 1:1f2d9982fa8c 62 p40 = gpio21,
hudakz 1:1f2d9982fa8c 63
hudakz 1:1f2d9982fa8c 64 // Extension board V2.1 pin names
hudakz 1:1f2d9982fa8c 65 P0 = gpio17,
hudakz 1:1f2d9982fa8c 66 P1 = gpio18,
hudakz 1:1f2d9982fa8c 67 P2 = gpio27,
hudakz 1:1f2d9982fa8c 68 P3 = gpio22,
hudakz 1:1f2d9982fa8c 69 P4 = gpio23,
hudakz 1:1f2d9982fa8c 70 P5 = gpio24,
hudakz 1:1f2d9982fa8c 71 P6 = gpio25,
hudakz 1:1f2d9982fa8c 72 P7 = gpio4,
hudakz 1:1f2d9982fa8c 73 CE1 = gpio7,
hudakz 1:1f2d9982fa8c 74 CE0 = gpio8,
hudakz 1:1f2d9982fa8c 75 CS = gpio8,
hudakz 1:1f2d9982fa8c 76 SCLK = gpio11,
hudakz 1:1f2d9982fa8c 77 MISO = gpio9,
hudakz 1:1f2d9982fa8c 78 MOSI = gpio10,
hudakz 1:1f2d9982fa8c 79 RXD = gpio15,
hudakz 1:1f2d9982fa8c 80 TXD = gpio14,
hudakz 1:1f2d9982fa8c 81 SCL = gpio3,
hudakz 1:1f2d9982fa8c 82 SDA = gpio2,
hudakz 1:1f2d9982fa8c 83 PWM = gpio18,
hudakz 1:1f2d9982fa8c 84
hudakz 1:1f2d9982fa8c 85 // Arduino pin names on the Extension board V2.1
hudakz 1:1f2d9982fa8c 86 D2 = gpio18,
hudakz 1:1f2d9982fa8c 87 D3 = gpio23,
hudakz 1:1f2d9982fa8c 88 D4 = gpio24,
hudakz 1:1f2d9982fa8c 89 D5 = gpio25,
hudakz 1:1f2d9982fa8c 90 D6 = gpio4,
hudakz 1:1f2d9982fa8c 91 D7 = gpio17,
hudakz 1:1f2d9982fa8c 92 D8 = gpio27,
hudakz 1:1f2d9982fa8c 93 D9 = gpio22
hudakz 1:1f2d9982fa8c 94 } PinName;
hudakz 1:1f2d9982fa8c 95
hudakz 1:1f2d9982fa8c 96 typedef enum
hudakz 1:1f2d9982fa8c 97 {
hudakz 1:1f2d9982fa8c 98 PIN_INPUT,
hudakz 1:1f2d9982fa8c 99 PIN_OUTPUT
hudakz 1:1f2d9982fa8c 100 } PinDirection;
hudakz 1:1f2d9982fa8c 101
hudakz 1:1f2d9982fa8c 102 typedef enum
hudakz 1:1f2d9982fa8c 103 {
hudakz 1:1f2d9982fa8c 104 PullNone,
hudakz 1:1f2d9982fa8c 105 PullUp,
hudakz 1:1f2d9982fa8c 106 PullDown,
hudakz 1:1f2d9982fa8c 107 OpenDrain,
hudakz 1:1f2d9982fa8c 108 PullDefault = PullNone
hudakz 1:1f2d9982fa8c 109 } PinMode;
hudakz 1:1f2d9982fa8c 110
hudakz 1:1f2d9982fa8c 111 #endif // _PIN_NAMES_H_