Archive | MSP430

Exploring the TI Stellaris platform with Energia Arduino-compatible IDE

Introduction

In the same manner as their MSP430 development board, Texas Instruments also have another LaunchPad board with their powerful Stellaris LM4F120H5QR microcontroller. It’s an incredibly powerful and well-featured MCU – which offers an 80 MHz, 32-bit ARM Cortex-M4 CPU with floating point, 256 Kbytes of 100,000 write-erase cycle FLASH and many peripherals such as 1MSPS ADCs, eight UARTs, four SPIs, four I2Cs, USB & up to 27 timers, some configurable up to 64-bits.

That’s a bucket of power, memory and I/O for not much money – you can get the LaunchPad board for around $15. This LaunchPad has the in-circuit debugger, two user buttons, an RGB LED and connectors for I/O and shield-like booster packs:

and the other side:

However the good news as far as we’re concerned is that you can now use it with the Energia Arduino-compatible IDE that we examined previously. Before rushing out to order your own Stellaris board, install Energia and examine the available functions and libraries to make sure you can run what you need. And if so, you’re set for some cheap Arduino power.

Installation

Installation is simple, just get your download from here. If you’re running Windows 7 – get the USB drivers from here. When you plug your LaunchPad into the USB for the first time, wait until after Windows attempts to install the drivers, then install drivers manually after download via Device manager … three times (JTAG, virtual serial port and DFU device). Use the debug USB socket (and set the switch to debug) when installing and uploading code. If you get the following warning from Windows, just click “Install this driver software anyway”:

Once the drivers are installed, plug in your LaunchPad, wait a moment – then run Energia. You can then select your board type and serial port just like the Arduino IDE. Then go ahead and upload the “blink” example…

stellarisblink

Awesome – check out all that free memory space. In the same manner as the MSP430, there are some hardware<>sketch differences you need to be aware of. For example, how to refer to the I/O pins in Energia? A map has been provided for front:

stellarpad-e28094-pins-maps1

… and back:

stellarpad-back-e28094-pins-maps1

As you can imagine, the Stellaris MCUs are different to an AVR, so a lot of hardware-specific code doesn’t port over from the world of Arduino. One of the first things to remember is that the Stellaris is a 3.3V device. Code may or may not be interchangeable, so a little research will be needed to match up the I/O pins and rewrite the sketch accordingly. For example, instead of digital pins numbers, you use PX_Y – see the map above. So let’s say you want to run through the RGB LED… consider the following sketch:

Which simply blinks the red, green and blue LED elements in series. Using digital inputs is in the same vein, and again the buttons are wired so when pressed they go LOW. An example of this in the following sketch:

And for the non-believers:

Where to from here? 

Sometimes you can be platform agnostic, and just pick something that does what you want with the minimum of time and budget. Or to put it another way, if you need a fast CPU and plenty of space but couldn’t be bothered don’t have time to work with Keil, Code Composer Studio, IAR etc – the Energia/Stellaris combination could solve your problem. There’s a growing Energia/Stellaris forum, and libraries can be found here. At the time of writing we found an I2C library as well.

However to take full advantage of the board, consider going back to the TI tools and move forward with them. You can go further with the tutorials and CCS etc from Texas Instruments own pages.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, arm cortex, energia, launchpad, lesson, LM4F120H5QR, MSP430, product review, software review, stellaris, TI, tiva-c, tutorial2 Comments

Exploring the TI MSP430 platform with Energia Arduino-compatible IDE

Introduction

Over the last year or so Texas Instruments have been literally pushing their MSP430 development platform hard by offering an inexpensive development kit – their LaunchPad. For around ten dollars (not everyone could get it for $4.30) it includes a development board with flash emulation tool and USB interface, two of their microcontrollers, crystal, USB cable and some headers. It was (is?) a bargain and tens of thousands of LaunchPads were sold. Happy days.


However after the courier arrived and the parcel was opened, getting started with the LaunchPad was an issue for some people. Not everyone has been exposed to complex IDEs or university-level subjects on this topic. And to get started you needed to use a version of Code Composer Studio or IAR Embedded Workbench IDEs, which scared a few people off. So those LaunchPads went in the cupboard and gathered dust.

Well now it’s time to pull them out, as there’s a new way to program the MSP430 using a fork of the Arduino IDE – Energia. Put simply, it’s the Arduino IDE modified to compile and upload code to the LaunchPad, which makes this platform suddenly much more approachable.

Getting Started

You’ll need to download and install the appropriate USB drivers, then the IDE itself from here. To install the IDE you just download and extract it to your preferred location, in the same manner as the Arduino IDE. Then plug your LaunchPad into the USB. Finally,  load the IDE. Everything is familiar to the Arduino user, except the only surprise is the colour (red as a nod to TI perhaps…):

ide

Looking good so far. All the menu options are familiar, the files have the .ino extension, and the preferences dialogue box is how we expect it. Don’t forget to select the correct port using the Tools > Serial port… menu. You will also need to select the type of MSP430 in your LaunchPad. At the time of writing there is support for three types listed below (and the first two are included with the LaunchPad v1.5):

  • MSP430G2553 – <=16 MHz, 16KB flash, 512b SRAM, 24 GPIO, two 16-bit timers, UART, SPI, I2C, 8 ADC channels at 10-bit, etc. Cost around Au$3.80 each**
  • MSP430G2452 – <=16 MHz, 8KB flash, 256b SRAM, 16 GPIO, one 16-bit timer, UART, I2C, 8 ADC channels, etc. Cost around Au$2.48 each**
  • MSP430G2231 – <=16 MHz, 2KB flash, 128b SRAM, 10 GPIO, one 16-bit timer, SPI, I2C, 8 ADC channels, etc. Cost around Au$3.36 each**

** One-off ex-GST pricing from element14 Australia. In some markets it would be cheaper to buy another LaunchPad. TI must really be keen to get these in use.

There are some hardware<>sketch differences you need to be aware of. For example, how to refer to the I/O pins in Energia? A map has been provided for each MSP430 at the Energia wiki, for example the G2553:

g2553pinouts

As you can imagine, MSP430s are different to an AVR, so a lot of hardware-specific code doesn’t port over from the world of Arduino. One of the first things to remember is that MSP430s are 3.3V devices. Code may or may not be interchangeable, so a little research will be needed to match up the I/O pins and rewrite the sketch accordingly. You can refer to pins using the hardware designator on the LaunchPad (e.g. P1_6) or the physical pin number. For example – consider the following sketch:

You could have used 2 (for physical pin 2) instead of P1_0 and 14 (physical pin … 14!) instead of P1_6. It’s up to you. Another quick example is this one – when the button is pressed, the LEDs blink a few times:

Due to the wiring of the LaunchPad, when you press the button, P1_3 is pulled LOW. For the non-believers, here it is in action:

So where to from here? There are many examples in the Energia IDE example menu, including some examples for the Energia libraries. At the time of writing there is: Servo, LiquidCrystal, IRremote, SPI, wire, MSPflash and Stepper. And as the Energia project moves forward more may become available. For help and discussion, head over to the 4-3-Oh forum and of course the Energia website. And of course there’s the TI MSP430 website.

Conclusion

Well that was interesting to say the least. If you have a project which needs to be low-cost, fits within the specifications of the MSP430, has a library, you’re not hung up on brand preference, and you just want to get it done – this is a viable option. Hopefully after time some of you will want to work at a deeper level, and explore the full IDEs and MSP430 hardware available from TI. But for the price, don’t take my word for it – try it yourself. 

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, energia, I2C, LCD, lesson, MSP430, MSP430G2231, MSP430G2452, MSP430G2553, TI, tutorial14 Comments


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