Review of Embedded Pi

Table of contents

RoadTest: Embedded Pi

Author: bradbas

Creation date: 10 Jul 2013

Evaluation Type: Evaluation Boards

Did you receive all parts the manufacturer stated would be included in the package?: False

What other parts do you consider comparable to this product?: Microchip 18F8722 Device previously evaluated

What were the biggest problems encountered?: The only problem I encountered was needing to create a new cable from the SWD debugger to the Embedded Pi Board JP2

Detailed Review:

Received Embedded Pi, no software included but free development tools for STM32 Cortex M3 Arm processor are available for download. My review is focused on creating a stand alone application with the STM32 processor

These are the steps I used before creating my application:

• Download free coocox coIDE from coocox.org
• Install coIDE development tool install manager
• Using install manager download and install CoIDE and ColinkEx USB Driver
• For debugging and Flashing the device I used the ARM-JTAG-COOCOX USB device from www.olimex.com
• I Plugged in the USB Debugger to verify that window recognizes the device.  No issues

My Review:

• The application I created was to control a string of 100 WS2811 RGB 12mm dots. I had previously created this application to work on the Microchip PIC18F8722 device and ported it over to this ARM platform.
• Note: The debugger came with a different cable (20 pin) and the Embedded Pi board SWD is a 10 pin cable. To get around this I created a special cable to pass all the required signals from the 20 pin to the 10 pin arrangement.
• The Embedded Pi board JP1 had to be changed to allow 5V level signal out of the GPIO port D that I used.
• The Embedded Pi board powered up without the debugger connected with LED1 flashing. Since LED1 was connected to GPIO pin 13, this indicated the processor was running a program that was flashing the LED. This was a very good sign I had a working board.
• I connected my WS2811 RGB dot string to +5V power supply and the data line with ground reference to GPIO PD2 which I had access to on JP9 Pin 15 and Ground on JP7 Pin 11
• To create the application I used the Embedded Pi manual to setup a stand alone project that used the CMSIS Core in common, CMSIS_Boot in Boot, RCC and GPIO in Peripheral.ST modules.
• From there I ported my Microchip code into the main.c module, fine tuned the timing and everything worked with minimal modification to my original Microchip code. I was able to fully use my SWD debugger tool for development. I have attached the complete project I created to run the RGB Dots for anyone to use

My Conclusions:

The Embedded Pi is capable of interfacing with the Raspberry Pi, Arduino Shields, and running stand alone as an ARM Processor system. My review focused on the stand alone aspect of the Embedded Pi board and I have no issues to report. The CooCox development tools worked great from downloading/installing to developing my application. My debugger interfaced with the board flawlessly.

I completely reviewed the Embedded Pi schematic and mythology with connecting to the Raspberry Pi and Arduino Shields and even though I only worked on the STM processor alone I foresee no issues with using the Embedded Pi board as intended by the manufacturer.

The Embedded Pi User manual and schematics supplied by downloading from CooCox was very well organized and easy to follow and find the required information.

I have previously reviewed Microchip and Atmel devices on my own and to have a chance to evaluate the Embedded Pi board with the STM Arm 32 processor was a pleasure. When comparing the board against other platforms I give it high marks. I had trouble with other platforms for evaluating and by having no trouble with this board I give it an A+

Thank You