Hi

I suppose such questions have been posed upteen times but I guess a newbie like myself, searching thru the internet, get more confused than enlightened as I try to consolidate the answers for different sub-component. So I guess I might as well asked in one place. Thanks for your patience!

I am trying to build a system that involves a PIC microcontroller. Am trying to determine which one to choose. My requirements :

1) a LM75 temperature sensor - how many pins needed on PIC
2) 2 x 16 or 24 LCD display - 7 pins on PIC?
3) a photocell - how many pins needed on PIC
4) a speaker for simple beeps - how many pins
5) a 4x4 matrix keypad - how many pins
6) clock to tell time - "
7) USB port for upload/download to PC - "
8) RS232 port to send 5V signal to another relay device (??) - "
9) battery operated for normal usage


Based on the above, how many ports on a PIC would be needed? Any recommendations on the type of PIC (16F & 18F??) needed?

Many thanks!

 

You need at least 28 pin package unless you do a compact design under a 18 pin PIC.

The PIC must have following modules to meet your requirements.
AD/USART/TMRX etc...........

From PIC 16F series 16F87X,16F88X or in 18F series PIC18F45XX (+USB)....

__________________
Gayan

My Website
http://gsmicro.blogspot.com/

 

hi,
I would go with the 18FXXXX 40 pin series, if you really want USB.

It may be an overkill on the number of available pins, but you do have the option for expansion.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Probably the 18F4550 would do you just fine, and it gives you some headway for additional pins if required...

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

That would be a fine choice, just be warned USB is not exactly beginners stuff. You'll need either C18 or Swordfish BASIC (the SE version does not support USB but the commercial version does)

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

hi Bill,
For your memory database, Oshonsoft Simulator 18F4550 has USB support, its an addon option to the standard 18Fxxxx simulator, reasonably priced.

Regards

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

A little off topic, can you load the .hex files into the simulator?

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

Nevermind.. just reading through the costs of the program, $65 for the compiler which requires the simulator license of $55.. thats pretty hefty Is that in euro too?

I think I'll stick to the SF HID Software that it creates for each USB program


Urahara, take a look in the Swordfish help file under USB - this is not a good place to start for beginners with micro controllers, but none the less you have to have something to inspire too

A better newbie project would be to program your first PIC! This might help?

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

IMO the OshonSoft simulator (and your Junebug emulator) are top notch. I can't say I'm a fan of OshonSofts BASIC or Assembler. It's a good BASIC but Swordfish is a great BASIC.

Apparently they're working on debug support for Swordfish. Personally I found a quick fix in just sending debug data through the UART much like the old BASIC Stamp.

Yes, that's the only way I've found but it's not so handy as you can't compare your source code to the assembled code.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

Hi Gramo,

The 18Fxxxx for personal use is Euro29 and the USB add on is Euro49.. [ £23GBP and £38GBP as per todays exchange]

You can buy bundles for the complete set of Sims, at a discount.

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Thanks Eric,

It does look nice, downloading some trail software now

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

Hi Gramo aka Spency,
When you try the 18F, download Bills JPUG June Issue,from the BlueRoomElectronics site, try the Junebug Tutor 18F1320 Simulator for the Oshonsoft.

Regards

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Hi All

Thks for the responses! Will post further queries if I need more help!

Rgds

 

Some more questions :

For my project, I would like to have to hv the capability for my PC to download data with a pre-defined format to the EEPROM (say a 24CXX module). The PIC would then pick up the data and perform the necessary operation such as displaying the data, apply a mathematical formula against it, etc.

The 'problem' with present PCs is that they only hv USB ports. My notebook has 3xUSB ports with no RS232 port (didnt notice that when i bought the notebook, assuming that all PCs hv RS232 ports and mistook the video port for one!! ).

I hv come across drivers that simulates a USB port as a COM port. Is this a simpler way to transfer data from PC to the 24CXX? So to connect the PC to the PIC, does it mean then that I am now restricted to the 18Fxxxx that comes with USB? Or is there a way to still use the 16Fs but how do I connect it to the PC that only has USB ports? Putting things in context, is it still better to go 18F or 16F?

Thks!

 

You can use USB to Serial cable I used that cable for many projects of mine & it works fine.

__________________
Gayan

My Website
http://gsmicro.blogspot.com/