Nice tutorial for writing and debugging plain C on ARM Cortex-M3 STM32F103

Jacob Mossberg wrote nice tutorial how to program in C ARM Cortex-M3 with GCC and how to debug it with GDB and OpenOCD.

We like very much the hardware he is using 🙂 STM32-H103 and ARM-USB-OCD-H.

 

ESP8266 Building Hello World Blink LED and Simple Web Server to drive the Relay and check Button status

ESP8266-EVB is small 57×50 mm board with Relay and Button which are connected to Internet via ESP8266 WIFI module.

ESP8266 has inside Xtensa106 processor and RF front end circuit, you do not need separate processor to drive the relay and read the button as ESP8266 can be programmed with custom code.

Here we will explain how to setup your tools and make your first project.

First you need to install your tools. It’s simple, just follow the instructions here: https://github.com/esp8266/esp8266-wiki/wiki/Toolchain

There are just few small mistakes as some commands will require SUDO before them and some paths are not exactly same, but you have to follow the steps and once you get error to read and correct the problem.

Here is what we do on Ubuntu 14.04 LTE 64-bit:

sudo apt-get install git autoconf build-essential gperf bison flex texinfo libtool libncurses5-dev wget gawk libc6-dev-amd64 python-serial libexpat-dev
sudo mkdir /opt/Espressif
sudo chown $username /opt/Espressif/
sudo cd /opt/Espressif
sudo git clone -b lx106 git://github.com/jcmvbkbc/crosstool-NG.git 
cd crosstool-NG
./bootstrap && ./configure --prefix=`pwd` && make && make install
./ct-ng xtensa-lx106-elf
./ct-ng build
PATH=$PWD/builds/xtensa-lx106-elf/bin:$PATH

cd /opt/Espressif
mkdir ESP8266_SDK
wget -O esp_iot_sdk_v0.9.3_14_11_21.zip https://github.com/esp8266/esp8266-wiki/raw/master/sdk/esp_iot_sdk_v0.9.3_14_11_21.zip
wget -O esp_iot_sdk_v0.9.3_14_11_21_patch1.zip https://github.com/esp8266/esp8266-wiki/raw/master/sdk/esp_iot_sdk_v0.9.3_14_11_21_patch1.zip
unzip esp_iot_sdk_v0.9.3_14_11_21.zip
unzip esp_iot_sdk_v0.9.3_14_11_21_patch1.zip
mv esp_iot_sdk_v0.9.3 ESP8266_SDK
mv License ESP8266_SDK/esp_iot_sdk_v0.9.3

cd /opt/Espressif/ESP8266_SDK/esp_iot_sdk_v0.9.3
sed -i -e 's/xt-ar/xtensa-lx106-elf-ar/' -e 's/xt-xcc/xtensa-lx106-elf-gcc/' -e 's/xt-objcopy/xtensa-lx106-elf-objcopy/' Makefile
mv examples/IoT_Demo .

cd /opt/Espressif/ESP8266_SDK/esp_iot_sdk_v0.9.3
wget -O lib/libc.a https://github.com/esp8266/esp8266-wiki/raw/master/libs/libc.a
wget -O lib/libhal.a https://github.com/esp8266/esp8266-wiki/raw/master/libs/libhal.a
wget -O include.tgz https://github.com/esp8266/esp8266-wiki/raw/master/include.tgz
tar -xvzf include.tgz

cd /opt/Espressif
wget -O esptool_0.0.2-1_i386.deb https://github.com/esp8266/esp8266-wiki/raw/master/deb/esptool_0.0.2-1_i386.deb
dpkg -i esptool_0.0.2-1_i386.deb

cd /opt/Espressif
git clone https://github.com/themadinventor/esptool esptool-py
ln -s $PWD/esptool-py/esptool.py crosstool-NG/builds/xtensa-lx106-elf/bin/

For less experienced users, we are preparing VirtualBox disk image which to run on Virtual machine on any OS like Linux, MAC OS, Windows, and everything inside is pre-configured and ready to use, hopefully we will upload this image on ESP8266-EVB web page tomorrow as we didn’t manage to complete it today.

Once you have setup the Tools you can download our examples from GitHub:

cd /opt/Espressif
git clone https://github.com/OLIMEX/ESP8266.git
cd ESP8266-EVB-blinkLED
make

the project will be compiled and you will see something like this:

AR build/app_app.a
LD build/app.out
FW firmware/0x00000.bin
FW firmware/0x40000.bin

congratulations you made your first code!

now we hae to load it to ESP8266-EVB

you need: ESP8266-EVB, 5V adapter like SY0605E, USB-Serial-Cable-F
connect the USB-SERIAL-CABLE-F to ESP8266-EVB UEXT connector as follows:

• blue wire to pin#2
• green wire to pin#3
• red wire to pin#4

plug the USB cable to your computer USB connector and check which serial port it connects by typing:

lsusb

your computer should display something like:

...

Bus 004 Device 005: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

...

if you type:

ls /dev/tty*

you will see:

.... /dev/ttyUSB0 ....

If the USB device is with different name you have to update it in the makefile.

After the code is compiled with no errors you can write it to ESP8266 by following these steps:

1.  first you have to press button and hold it and to apply power 5V, ESP8266 will enter bootloader mode
2. type ‘sudo make flash’ and wait until code is loaded:

sudo make flash
/opt/Espressif/esptool-py/esptool.py --port /dev/ttyUSB0 write_flash 0x00000 firmware/0x00000.bin 0x40000 firmware/0x40000.bin
Connecting...
Erasing flash...
Writing at 0x00007300... (100 %)
Erasing flash...
Writing at 0x00061200... (100 %)

Leaving...

now Green LED must start blinking!

So far so good, you just made blinking LED on ESP8266, now let’s make something more complicated – to run Embedded web server on ESP8266, go to esphttpd project directory:

cd /opt/Espressif/ESP8266/esphttpd
make

then upload the code

sudo make flash

then upload web pages with:

sudo make htmlflash

Now ESP8266 firmware is uploaded and ESP8266 create Embedded server.

Scan for WIFI which name starts with ESP_XXXXXXX where XXXXXX is the ESP8266 MAC address and connect to this network then open browser at http://192.168.4.1 you will see this home page:

if you click on Relay button in the right side you will see new page:

On this page you can switch the on-board relay by clicking on ON and OFF button

If you click on the Button button in the right side you will see new page:

If you click on Start scan the web page will start to refresh each second and display the button status if you click on Stop scan the page will not refresh.

This is very basic demo code which can be used as template for your own projects!

Tutorial: Cross-Compiling and GDB debugging on A13-OLinuXino

Agilart is open source project which provide web based visual designer and allow even people with no technical background to complete Iternet-Of-Things projects. You can learn more about this project here: http://www.agilart.com/

Agilart team bought iMX233-OLinuXino-MICRO and they made some nice tutorials: http://www.agilart.com/blog/the-olinuxino-micro-wifi-sd-cards-farbric , http://www.agilart.com/blog/buildingForOlinuxino , so Santa Claus surprised them with A13-OLinuXino-MICRO for Christmas 🙂

Agilart team didn’t waste time and they come up today with new nice tutorial how to setup Eclipse and GCC to cross compile and debug on A13-OLinuXino http://www.agilart.com/blog/debugging-on-embedded-using-opensource-tools-part-1

Good work!