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/DigitalIn.h@2:131555dc6fb7, 21 months ago (annotated)
- 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?
User | Revision | Line number | New contents of line |
---|---|---|---|
hudakz | 1:1f2d9982fa8c | 1 | #ifndef _DIGITAL_IN_H_ |
hudakz | 1:1f2d9982fa8c | 2 | #define _DIGITAL_IN_H_ |
hudakz | 1:1f2d9982fa8c | 3 | |
hudakz | 1:1f2d9982fa8c | 4 | #include "BCM2835.h" |
hudakz | 1:1f2d9982fa8c | 5 | |
hudakz | 1:1f2d9982fa8c | 6 | class DigitalIn |
hudakz | 1:1f2d9982fa8c | 7 | { |
hudakz | 1:1f2d9982fa8c | 8 | public: |
hudakz | 1:1f2d9982fa8c | 9 | DigitalIn(PinName pin) : |
hudakz | 1:1f2d9982fa8c | 10 | gpio(pin) |
hudakz | 1:1f2d9982fa8c | 11 | { |
hudakz | 1:1f2d9982fa8c | 12 | gpio_dir(gpio, PIN_INPUT); |
hudakz | 1:1f2d9982fa8c | 13 | gpio_write(gpio, LOW); |
hudakz | 1:1f2d9982fa8c | 14 | } |
hudakz | 1:1f2d9982fa8c | 15 | |
hudakz | 1:1f2d9982fa8c | 16 | DigitalIn(PinName pin, PinMode mode) : |
hudakz | 1:1f2d9982fa8c | 17 | gpio(pin) |
hudakz | 1:1f2d9982fa8c | 18 | { |
hudakz | 1:1f2d9982fa8c | 19 | gpio_dir(gpio, PIN_INPUT); |
hudakz | 1:1f2d9982fa8c | 20 | gpio_mode(pin, mode); |
hudakz | 1:1f2d9982fa8c | 21 | } |
hudakz | 1:1f2d9982fa8c | 22 | |
hudakz | 1:1f2d9982fa8c | 23 | int read() { return gpio_read(gpio); } |
hudakz | 1:1f2d9982fa8c | 24 | void mode(PinMode mode) { mode == PullUp ? gpio_write(gpio, HIGH) : gpio_write(gpio, LOW); } |
hudakz | 1:1f2d9982fa8c | 25 | void attach(FunctionPointer fptr, Digivalue m) { attachInterrupt(gpio, fptr, m); } |
hudakz | 1:1f2d9982fa8c | 26 | operator int() { return read(); } |
hudakz | 1:1f2d9982fa8c | 27 | protected: |
hudakz | 1:1f2d9982fa8c | 28 | PinName gpio; |
hudakz | 1:1f2d9982fa8c | 29 | }; |
hudakz | 1:1f2d9982fa8c | 30 | |
hudakz | 1:1f2d9982fa8c | 31 | #endif // _DIGITAL_IN_H_ |
hudakz | 1:1f2d9982fa8c | 32 |