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 .
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
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:
- 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:
- Double click on Blinky.pro to open it for editing and add new libraries by inserting a new line as follows:
- 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.
- Press Ctrl+c to stop running the application.
include/DigitalInOut.h
- Committer:
- hudakz
- Date:
- 21 months ago
- Revision:
- 1:1f2d9982fa8c
File content as of revision 1:1f2d9982fa8c:
#ifndef _DIGITAL_IN_OUT_H_ #define _DIGITAL_IN_OUT_H_ #include "BCM2835.h" class DigitalInOut { public: DigitalInOut(PinName pin) : gpio(pin) { gpio_dir(gpio, PIN_INPUT); gpio_write(gpio, LOW); } DigitalInOut(PinName pin, PinDirection direction, PinMode mode, int value) : gpio(pin) { if (direction == PIN_INPUT) { gpio_dir(gpio, PIN_INPUT); if (mode == PullUp) gpio_write(gpio, HIGH); else gpio_write(gpio, LOW); } else { gpio_dir(gpio, PIN_OUTPUT); gpio_write(gpio, value); } } void write(int value) { gpio_write(gpio, value); } int read() { return gpio_read(gpio); } void output() { gpio_dir(gpio, PIN_OUTPUT); } void input() { gpio_dir(gpio, PIN_INPUT); } DigitalInOut &operator =(int value) { write(value); return *this; } operator int() { return read(); } protected: PinName gpio; }; #endif // _DIGITAL_IN_OUT_H_