Deciding Micro controller

[parthshah08]

Hey,

So I am making a project. I am building a smart pill/medicine box and which would help old people with their prescriptions. Just simple stuff, like help them locating the right pill to take at right time. So, it would be having different boxes and at specific time a compartment will glow up. It is pretty simple concept right now, but I might be expanding with recording of which pills a patient has missed or somethiing like that.

So, I am not sure which controller should I go with . I know how to programme 8051 , but my professor wants me to go with Xmega.
So is there any other controller which woulld be more efficient in this case?

 

[Nigel Goodwin]

It's a simple application, so anything will do - PIC's are one of the most popular choices - particularly where only a small device is needed.

 

[kubeek]

Xmega is definitely an overkill for such application, some normal atmega should be more than enough. How many pins do you need?
You could also try some of the MSP430 series from TI, those are designed to be very low power and have extensive sleep modes which could be a big advantage if you are going to power this thing from a battery.

 

[NorthGuy]

To keep things simple, you will need a pin for each LED, a pin for each box to detect if the patient had it open to take pills, some pins to do whatever you want to do when you figured out they missed the pill, probably some pins for clocks or crystal. You will probably need LCD to set the time and enter the settings (or Ethernet/WiFi to download it directly from the doctor's office). That's a lot of pins, but the programming task is very simple. I would figure the exact number of pins, then would get the simplest controller with enough pins.

 

[KeepItSimpleStupid]

FWIW: Interesting concept: https://www.medminder.com/

More complicated ones are out there too.

 

[Misterbenn]

You might want a Micro with a real time clock.

 

[3v0]

Microchip has a few microcontrollers with the RTC built in. Once less chip on the board is a good thing.

Like Nigel said any processor can do this job. Pick what is easy for you unless you want the learning experiance.

 

[Nigel Goodwin]

Microchip has a few microcontrollers with the RTC built in. Once less chip on the board is a good thing.

The 16F1827 would be a good choice - RTC built-in, ultra low consumption, loads of low power modes and options, and plenty of other useful peripherals - it's also an enhanced 14 bit core, with extra VERY useful functions.

Best of all, it's a very cheap device

 

[geko]

The 16F1827 would be a good choice - RTC built-in,

I don't think it does - unless you're referring to the 32KHz oscillator on Timer 1.

 

[Nigel Goodwin]

I don't think it does - unless you're referring to the 32KHz oscillator on Timer 1.

I am - simple and easy to use - and VERY low consumption.

 

[Ian Rogers]

I am - simple and easy to use - and VERY low consumption.

Wont keep proper time though surely!!! Its not really a watch crystal!!

 

[geko]

Wont keep proper time though surely!!! Its not really a watch crystal!!

The external oscillator on Timer 1 uses a watch crystal so yes it should but you have to implement the RTC itself in software.

 

[Ian Rogers]

Sorry! I mis-interpreted I thought you were talking about the internal 32khz..

 

[Nigel Goodwin]

Wont keep proper time though surely!!! Its not really a watch crystal!!

As already pointed out, you simply hang a 32KHz watch crystal and a couple of caps on the pins, simples!!

My GSM modem project I've been involved in uses exactly that, and is designed to give a five year battery life - waking up every 'four weeks' (adjustable via text message during setup) and sending confirmation it's still working (thus preventing the card from expiring).

 

[3v0]

The PIC18F26J50 is $3 and change at Newark.

It has a Hardware RTCC just as if it were connected to a clock chip. Requires a clock crystal. See section 17.0 Real-Time Clock and Calendar (RTCC) in the datasheet

**broken link removed**

 

[Nigel Goodwin]

The PIC18F26J50 is $3 and change at Newark.

Which is about double the price of the 16F1827

 

[3v0]

Which is about double the price of the 16F1827

Point made but its there if he wants to use it. I just picked the first on on the list. There are about 20 of them. For on off's who cares about the extra buck and a half.

 

[Nigel Goodwin]

Point made but its there if he wants to use it. I just picked the first on on the list. There are about 20 of them. For on off's who cares about the extra buck and a half.

But what advantage does it give?.

 

[3v0]

The advantage is that you get a hardware clock calendar on the chip. In this case the student does not have to place a RTC chip on his board or include the code to use a timer as a clock. I am not sure what all the built in RTCC does anyone who really cares can check the datasheet.

 

[Nigel Goodwin]

The advantage is that you get a hardware clock calendar on the chip. In this case the student does not have to place a RTC chip on his board or include the code to use a timer as a clock.

But you've got to write the code to setup and then access the RTC chip, which is likely to be MORE code than using the timer with an external 32KHz crystal, there seems little advantage at all (hence my question?).