Arch BLE

Arch BLE is an mbed enabled development board based Nordic nRF51822. With Arduino form factor and Grove connectors, it is extremely easy to create a bluetooth low energy device.

The nRF51822 is a powerful multi-protocol single chip solution for ULP wireless applications. It incorporates Nordic’s latest best-in-class performance radio transceiver, an ARM Cortex M0 MCU and 256kB flash + 16kB RAM memory. The nRF51822 supports Bluetooth® low energy and 2.4 GHz protocol stacks.

Features

mbed enabled
- Online IDE
- Easy to use C/C++ SDK
- Handy libraries
CMSIS DAP based on LPC11U35
- Drag-n-drop programming
- Debug using CMSIS DAP standard
- USB virtual serial for communication
Arduino form factor with Grove connectors
Nordic nRF51822 Multi-protocol Bluetooth® 4.0 low energy/2.4GHz RF SoC
- ARM Cortex M0 processor
- 256kB flash/16kB RAM
- Configurable I/O mapping for digital I/O
USB Micro B connector

Pinout

Get Started

Click this link to login or signup to mbed
Import the mbed_blinky program
Click the Compile icon of the top toolbar to compile the program, then download a compiled hex file.
Drag-n-drop the downloaded hex file into the MBED disk

You can open main.cpp to change the program. For example, use the following code to blink the LED every 0.1s

#include "mbed.h"

DigitalOut led(p30);           // on-board led is connected to p30

int main()
{
    while (true) {
        led = !led;
        wait(0.1);
    }
}

Note

If you get a compiling error that 'device.h' is not find, try to update the mbed library to the latest revision in your program.

Applications

Color Pixels, a colorful LED strip, can be controlled by mobile phone.

Hardware

Arch BLE
Digital RGB LED Strip
Android device with BLE

Make it run

Download BLE_Color_Pixels_Arch_BLE.hex
Copy the hex file to the MBED disk of your Arch BLE
Download the Color Pixels Android app

If you want to change the program, click this link to import the Color Pixels program to mbed online IDE.

If the BLE device is disconnected frequently, we can improve the stability by changing the BLE parameters - Advertising Duration (main.cpp), Min Interval and Max Interval (nRF51822/projectconfig.h)

#define CFG_GAP_CONNECTION_MIN_INTERVAL_MS           20                     /**< Minimum acceptable connection interval */
#define CFG_GAP_CONNECTION_MAX_INTERVAL_MS          200                     /**< Maximum acceptable connection interval */

Update or Restore Firmware

The latest firmware version for the Arch BLE is v0203 built at Oct 08 2014. To check your firmware version and built date, open the MBED.HTM file of your MBED disk in a text editor.

Changelog:

2014-06-26 first version
2014-08-25 support to drag-n-drop hex file generated by gcc toolchain and without softdevice
2014-10-08 use USB EJECT INSET instead of reconnecting USB, increase intel hex data line buffer (from 64 bytes to 128 bytes)

Known issues:

issues when directly downloading the hex file into the MBED disk with the Chrome browser. The reason is the Chrome will create a temporary file to save the downloading data. When using the Chrome, please save your hex file to other place and then copy it to the MBED disk.

Firmware:

To flash a new firmware:

Hold the Arch BLE's button and power on it
A CRP DISABLD disk will pop up
- On Windows, replace firmware.bin with the above firmware
- On Linux/Mac, use command: dd if={new_firmware.bin} of={firmware.bin} conv=notrunc