It’s time for EFM32!!!

Hello everyone.

Some time ago I took part in Webinar “EFM32 MCU and Sensors ideal for Internet of Things” organized by Silicon Labs. It was very good presentation about their products. I recommend to visit their site silabs.com/IoT, soon I will upload some documents form webinarium. I think it will be very usefull for those who want to start develop devices for IoT or for those who are looking for some sensors for their devices.

Silicon labs got many starter kits. The one which aroused my interest was EFM32ZG-STK3200. Silicon Labs presenters also was talking about it during presentation. Heart of the kit is really low power Cortex M0+ mcu. On board we also find 1.28-inch SHARP Memory LCD-TFT, 2 buttons and 2 capacitive touch pads. There are also 2 user leds, cr2032 battery holder, expansion header and of course Integrated SEGGER J-Link USB  debugger.  That’s enough for those who starts with Cortex M0+ adventure, but there is one more thing that can not stay overlooked! It’s AEM - Advanced Energy Monitoring system used for precise current tracking, great future which makes EGM32ZG-STK3200 ideal platform for developing low power systems – really LOW power! In my opinion that’s the best future that almost every kit should have, and Silicon Labs showed that they understand user needs. Most time I was working with 

Cortex M0+ and Zero Gecko Starter kit in my project? Why not!

I’m going to build simple weather station, and EFM32ZG-STK3200 contains everything what I need and even more! Silicon Labs was giving starter kits to all qualified attendants of webinar.  So I got one EFM32ZG-STK3200 and also i got Sensor EXP CARD.. GREAT!!!

Sensor EXP card is expansion card for EFM32 zero gecko starter kit. It has Si701x/2x Relative Humidity and Temperature Sensors and Si114x UV Index, Ambient Light, Proximity and 3D Gesture Sensors. Great future is proximity and 3d gesture sensor. Normally you can switch off the device when there is nobody infront of the screen, and turn on when someone appear.

What is in the box?

 

 

In the box you will find:

• EFM32ZG-STK3200 Starter Kit 
• USB mini cable
• DVD with IAR Embeeded Workbench for SiLabs

In sensor EXP card you will find expansion card with Sony CR2032 3v battery.

EFM32ZG-STK3200 Starter Kit looks solid and it’s very well made, it should serve long time.  You will pay for it 69$ dollars. In the kit you will find  two user tact switch (+ one reset), two user leds, two capacitive touch buttons, battery holder and Sharp Memory LCD (cost about 18$) and ofcourse AEM (Advenced Energy Monitoring)!. With Sensor Exp card you will get humidity, temperature and optical sensors. This kit is great platform for those who want to start adventure with low power embedded systems. Someone would say that 69$ is too much, but remember in this price you got platform with arm microcontroller, AEM, good LCD display, user buttons etc, in one starter kit. I just add that every kit

Let’s get started!!!

After unboxing first thing what i have done was to test Sensor EXP Card with EFM32 kit. I was using Simplicity studio which i liked because you will find everything you need to start working with your kit in one place: all documentation, programs, even you are able to order samples or buy the uC. 

http://www.silabs.com/Support%20Documents/TechnicalDocs/energy-debugging-tools.pdf

Here you got Weather demo presenting Sensor EXP Card YouTube Video

This how power consumption was changing when hand is moved over the Sensor EXP Card.

I've started recording after restart mcu, after short period of initialization you can see that power consumption significantly increased. When hand was moved over 3d sensors, you can see rugged trace of power consumption. In this test, hand was moved 3 times. Average current consumption is 4mA!!! Cortex M4F with basic configuration (ALU + one port enabled) consumes 15 mA. Before intialization, power consumption was 219.23 uA.

Future plan

As  i mention i'm going to build simple Weather station which in the near future will be connected to home monitoring system. It looks like the EFM32 ZG kit is the best choice for this application. It's a pity the kit doesn't support code profiling, it would be greate to have 100% abilities to create software really low power, but using AEM in this installment should be enough to manage.