topic Choosing a Microcontroller in Other NXP Products

Choosing a Microcontroller

Iain — Fri, 06 Nov 2009 07:07:26 GMT

I am starting a project for my university course - I hope to build a basic GPS and heart-rate monitor device for a runner. Simply to log GPS and heart-rate data, to then be uploaded to a computer program.

With patchy experience using microcontrollers, I am looking for advice on which one to use. I need a MCU that i can interface to:

Heart-rate monitor receiver (Polar RMC01) - which gives 1ms 3V output each heart-beat detected from HRM,

GPS receiver unit (EM-406a) - outputs NMEA 0183 data string, probably at 1Hz frequency,

SD-card module (uDRIVE-uSD-G1) - to store 2 sets of data

Both GPSr and SD module use serial communication.

I have only used the Freescale HCS08, would this be suitable, or any other recommendations?

Thanks in advance for any advice.

Re: Choosing a Microcontroller

abartky — Fri, 06 Nov 2009 15:23:43 GMT

lain,

From the brief summary you have given, I would assume you would have no problem using an HCS08 device for this, especially as it appears all you have to do is record/calculate the heartrate on an incoming GPIO (probably best to route to a KBIP capable pin) and then handle the 2 UART serial ports to do file open/close/read/write via UART and also GPS ASCII data on a second UART.

As you will need 2 UART ports, that will limit your choice a little in that the lower pin count HCS08 usually have only one SCI (UART) port if any.

With that, it would appear that the QE family of processors would be a good choice as the QE16 and above all have 2 SCI ports, run at 3V and have good power saving features. The DEMOQE board is a good evaluation board for getting started and also the CPU is on a daughtercard that you can remove from the evaluation board and perhaps put on your project (NOTE: if you do this, be forewarned that the daughtercard is not fully aligned on a 0.1" matrix so you may have to fudge your connectors to your breadboard or protoboard if you are not building your own PCB). The QE16/QE32 also is available in a 28 pin SOIC, and SOIC breakout boards are readily available.

QE family web page is at: http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=S08QE&tid=m8Hp

Good luck on your project

Alan

Re: Choosing a Microcontroller

Iain — Wed, 11 Nov 2009 04:04:48 GMT

Alan,

After a bit more research and better understanding of what I need, it seems that the QE16/QE32 is the best choice for my project, so thanks for your help (and quick reply!)