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Selection of Micro controller from MSP430 family for wireless sensor node

Irfan Awan
Prodigy 230 points
Other Parts Discussed in Thread: CC1101, CC2540, MSP430F1611, MSP430F149, MSP430F2491

Hi everyone,

 We are targeting  for a wireless sensor node which contain Wireless transceiver, temperature sensor , accelerometer ,  and LED.

The sensor node will be powered by coin cell battery. We are targeting 5 year of battery life time. We already selected ultra low power Wireless transceiver  which has  SPI interface. Accelometer has also SPI interface, The sensor node will have Tiny OS . 

We have to select Processor  from MPS430 family .

1.Can you please recommend any specific processor . 

2.Can you please any reference article in which it is proven that TI MSP 430 processor family has better performance from Atmel ATmega processor for wireless sensor nod.

Regards

Irfan Awan

 

  • 0
    Guru 18595 points

    Hi! If you are not in a hurry, I think TI is releasing the "wolverine" which is the new generation of MSP430 with even lower power requirements. This should be by far the less power consuming chip. Please remember you can also achieve better power savings configuring the GPIO accordingly to low-power programming, or reducing the working frequency, something useful in WSN.

    Regarding your second question... what about this?

    http://www2.ife.ee.ethz.ch/~roggend/publications/wear/DSPMic_v1.1.pdf

    PS: The good thing in TI is the power consumption as well as this forum. Another good thing in MSP430 is the huge amount of examples and documentation but, if you do need very fast development, you can go with Arduino-like libraries! You do not specify the MAC protocol or the battery capacity but... TinyOS? I thought everybody was switching to Contiki.

    Anyway, we use to do Sensor Network deployments so I'll be very glad if you continue this thread with further details and perhaps I'll be able to provide you better info! Where do you work? :)

  • 0 in reply to kazola
    Genius 3770 points

    kazola said:
    If you are not in a hurry, I think TI is releasing the "wolverine"

    Well, there's already an established series of wireless devices within the MSP430 family: the CC430. See http://www.ti.com/corp/docs/landing/cc430/

    It's a full RF-SoC, has an integrated sub-1GHz radio-transceiver based on the CC1101, and it's used in the eZ430-Chronos watch.

    As much as I'm excited about "Wolverine", details of the family are still a little fuzzy. Besides, the whole FRAM technology's still fairly new, with its own hardware and software challenges (for example relatively slow operating frequencies, limited toolchain support for the memory model, etc).

    The CC430 however is already available and has been field tested (the Chronos watch being the most prominent example).

    Tony

  • 0 in reply to kazola
    Prodigy 230 points

    Hi Kazola,

    Thank you for your reply.

    Our company is located in Stockholm Sweden. Your observation regarding OS is interesting. We thought of using Tiny OS because we found lot of support for Tiny OS rather Contiki. But it would be interesting to read more about  Contiki support for MSP430 family. Can you please send some useful link regarding this .

    what you think is reason behind switching  fromTiny OS to Contiki reason ?

    Actually  we are in hurry so we have to select from current available MSP430.

    We will be using  Aloha as MAC protocol . The battery capacity is 0.42 Ah.

    As we already selected Wireless Transceiver  which has SPI Interface .

    How MSP430Fxx and MSP430Gxx series differ from power consumption.  

    What you will recommend from  MSP430 Processor  will best  from  low power  consumption point of view?

    1. 1-2 SPI interface

    2. 10 GPIO

    Regards

    Irfan Awan

     

  • 0 in reply to Irfan Awan
    Guru 18595 points

    First of all, there are several users here who know much more than me about MSP430, I'm usually at the CC2540 forum :)

    Tony is one of them and JMG another. And after 1000, it comes me :)

    As Tony says, the "wolverine" can take a while to come out.

    And if you want a finished product and it matches your RF frequency, go for CCx.

    If I do not remember wrong, Tmote Sky motes featured a MSP430F1611.

    http://www.sics.se/contiki/wiki/index.php/Simple_Contiki_Data_Collection_on_the_Tmote_Sky

    The reason to switch? I do not know, but TinyOS is based on nes-C, and I did not wanted to learn a C variation :) I think SPI should be more energy saving, if not, everybody would be using bit-banging but we can listen to other opinions.

    Finally, I have not worked with Aloha but, isn't it quite old? And in fact I think Contiki or TinyOS are not going to override this with its own 15.4 MAC? Please remember again I'm not used to Aloha so perhaps this sentence has not any sense. If you provide me with further info, perhaps we can even start some sort of European collaboration. I work in a university.

    Bye!

  • 0 in reply to Irfan Awan
    Guru 227245 points

    Irfan Awan said:
    As we already selected Wireless Transceiver  which has SPI Interface .

    So you already picked somethign for the most energy-consuming part of a wireless sensor. Depending on network requirements (just sending, or listening and sending, and if sending, how often/how much?), the energy consumption of the RF part is so much that the consumption of a (properly programmed) MSP doesn't really make a difference.

    However...

    Irfan Awan said:
    How MSP430Fxx and MSP430Gxx series differ from power consumption.  

    Not at all. The G series has partly reduced funcitonality (e.g. no support ofr a HF crystal), but if this feature isn't used on an F-series, there is no difference in operating current. The main difference between G and F types is the reduced amount of factury calibrations doen on teh G series. Only at one and not two temperatures for the ADC, less or even no frequency calibrations for the internal oscillator etc. THings that keep the costs low, but do not affect operating current at all.

    A difference makes the family. The MSP430F1611, which is sidely used (including my own projects) was the biggest MSP (flash/ram size and I/O) available for some time. And migrating to a newer one for existign projects doesn't pay, so it is still widely used. Even TI still uses the 1612 (more flash, less ram, same peripherals) in their FETs
    However, the 1611 requires 3.6V to operate on 8MHz and also requires a crystal to reach more than ~6MHz system clock. It has, however, ADC and DAC and two hardware UARTs/SPI/I2C.

    The 2x family offers higher maximum CPU speed that the 1x family and a slightly improved clock system (no crystal needed for maximum CPU speed).

    The 4x family contains internal drivers for controllerless glass LCD segments.

    The top devices are the 5x family MSPs with up to 256k flash, up to 18k ram, 25MHz, 32bit hardware multiplier and lots of peripherals. However, their operating current (especially for the parts with much ram) is a bit higher than for the others. (well, their ram can be partly deactivated if not in use)
    Also, the 5x devices do not need 3.6V for full speed operation, and can go as low as 1.8V (at also reduced current) if only a slow CPU clock is required.

    SO besides a low operating current, what else requirements does your project have? Analog inputs? Additional digital bus connections (SPI/I2C/UART)? I/O-Pins? Required timers/counters? PWM signal generation or D/A? Expected code size and ram requirements? Required processing power (many calculations or just signal forwarding?)

    There are about 400 different MSPs currently available. To pick one, some more criteria than just 'low current' are required. Else 'no processor' would be the lowest-power choice :)

  • 0 in reply to Jens-Michael Gross
    Prodigy 230 points

    Hi Jens-Michael, 

    Thank you for your detail reply.   Following  are sensors with their interface with micro controller in our sensor node.

    1. Wireless transceiver with SPI interface.

    2. Accelrometer with SPI interface

    3.Push button with  GPIO.

    4. Two LED with GPIO.

    5. Temperature Sensor (not decided but most probably GPIO  ). Can you please suggest some standard interface for different sensor because  we are planing to have more sensor in future.

    As we are planing to run real time OS on sensor . We have to select  from either TinyOS or Contiki.

    Can you please elaborate the memory foot print requirements   and development support for MSP430  for both OS. 

    For the time being I can see MSP430F149 as  our desired  microcontroller. What  you say about this?

    Kind Regards

    Irfan Awan

  • 0 in reply to Irfan Awan
    Guru 227245 points

    Irfan Awan said:
    . Can you please suggest some standard interface for different sensor

    The most widely used interfaces for sensors are UART, SPI and I2C. UART is a peer-to-peer and not suitable for more than one sensor.
    I2C allows attachment of up to 128 devices with just two signal pins. If you use an MSP with USCI module, I2C is relatively simple. It is, however, a bit slow (maximum throughput is ~40kB/s, half-duplex, if devices support high-speed mode) and has some protocol overhead. It is possible to do I2C with an USI module, but it is a bit more complex. You can even do it with two GPIO pins, if oyu want.
    SPI is by far the fastest and wuickest protocol. With an USCI module, 2MB/s are possible. Full duplex. And thre is no protocol overhead too. The only drawbakc is that you need a separate chip select signal (GPIO) for each sensor.

    Sensors are available with all three interfaces, sometimes SPI and I2C are supported by the same IC.

    There are sensors which do not have an itnernal intelligence and require direct GPIO control.

    Irfan Awan said:
    As we are planing to run real time OS on sensor . We have to select  from either TinyOS or Contiki.

    So you'll need  n MSP with a bit more ram. The G series has only a few 100 bytes, mso tlikely nto neough to run an OS at all, let alone doing something useful.

    Irfan Awan said:
    Can you please elaborate the memory foot print requirements   and development support for MSP430  for both OS. 

    Why don't you check the project pages of these? I didn't work with any of them, writing my own collection of code. No need for an OS and the overhead introduced by it. Things run faster and smaller if you do what is needed and do not add unnecessary code by adding a complete OS. For the convenience of an OS you pay with increased resource usage, slower execution speed and also the need to check all your actions against possible conflicts with the OS' internal operations.

    Irfan Awan said:
    For the time being I can see MSP430F149 as  our desired  microcontroller. What  you say about this?

    We use the 1611 in our projects. However, the 1x family is fairly outdated, so you should check out the 5x devices (e.g. the 5438A) for new projects. It is faster (25 vs. 8MHz), requires lower voltage (MSP1x requires 3.6V for 8MHz), has more and better peripherals (including 32bit hardware multiplier) and I/O and consumes less power. And is cheaper too.

  • 0 in reply to Jens-Michael Gross
    Prodigy 230 points

    Hi Jens-Michael,

    I have now selected MSP430F2491  as you suggested  MSP430F1xx series is outdated.  MSP430F2491 full fills the memory requirements for both Tiny OS and Contiki OS.

    Which evaluation  board   contains MSP430F2491. If non of Evaluation board contains MSP430F2491 then which one is closer to evaluate SPI, I2C and other interface with external sensor  .

    Regards

    Irfan Awan

  • 0 in reply to Irfan Awan
    Guru 227245 points

    Irfan Awan said:
    Which evaluation  board   contains MSP430F2491.

    There is no evaluation board for this MSP. The only thing available for it is a breakout board, which would be sufficient for attaching sensors and testing the communication functions. It is the MSP-TS430PM64 or alternatively the MSP-FET430U64  with bundled programmer.

    The 2491 does not have an ADC, but for SPI/I2C communication, any 2x family MSP with two USCI modules canbe used as replacement. However, I don't know of any 2x family evaluation board. The only one I know of is rather an eval board for the FG46xx which also has a 2x family MSP on it (but one without USCI module)
    But my information might be incomplete.

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