2
\$\begingroup\$

I've been thinking about getting into using some pic microcontrollers, and I found the below two things to help get me started. But, on the product page for the microcontroller, it says 20 mhz, but then in the description it says it has an 8mhz internal oscillator. Which is right? Also, with the programmer below, it says usb to serial adapters don't work, but I don't have any serial ports on my computer, is there anything I can do about that?

http://www.sparkfun.com/products/8
http://www.sparkfun.com/products/228

\$\endgroup\$
3
\$\begingroup\$

The pic 16F88 can run up to 20 MHz with an external oscillator. Then up to 8 MHz with the internal oscillator selected. This is usually done by setting the fuse bits(I use AVR not PICs so not completely sure on how to do that usually in the IDE).

As for the programmer I would look at just getting a PICKIT 2 or 3 for programming easy to use also made my microchip. And forgot to mention USB :).

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ Ok. I chose this programmer because of the price, and (this probably isn't good, but) I dislike in-circuit programming. Is there another similar to this that uses a usb interface? Also, you wouldn't happen to have a basic schematic on how to set up a pic with an external oscillator? \$\endgroup\$ – a sandwhich May 1 '11 at 18:19
  • \$\begingroup\$ Just googled and found that its connected to the PIC in the lower left hand side of the image. It uses two capacitors connected to osc1 and osc2. \$\endgroup\$ – Dean May 1 '11 at 18:23
  • 2
    \$\begingroup\$ That datasheet for any pic will specify how to connect the oscillator \$\endgroup\$ – Kellenjb May 1 '11 at 18:53
  • 2
    \$\begingroup\$ microchip.com/stellent/… <-Microchips out of circuit programmer. It will be very beneficial to do in circuit programing though, having to pop pics in and out of a programmer and bread board really takes a toll on the pins and will more then likely cause you problems that are hard to debug. \$\endgroup\$ – Kellenjb May 1 '11 at 18:55
5
\$\begingroup\$

Forget about those serial port programmers sold by Sparkfun and other suppliers, they aren't supported by MPLAB, they don't program the latest chips, they don't work very well, and you won't get in-circuit debugging. If you don't believe me, look at the posts about them on the Sparkfun forums. Here is a typical tale of woe.

Get a Microchip PICkit 2 or 3, they plug straight into a USB port and the PICkit 3 supports all current devices, and works with the new MPLAB-X IDE.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ Why the downvotes? \$\endgroup\$ – Leon Heller May 1 '11 at 19:04
  • \$\begingroup\$ I recently bought a 555cn timer ic for another purpose, would this work as an external oscillator? \$\endgroup\$ – a sandwhich May 3 '11 at 2:14
  • \$\begingroup\$ It would, but there isn't any point. The internal oscillator will be a lot faster and more stable. \$\endgroup\$ – Leon Heller May 11 '11 at 10:21
  • \$\begingroup\$ Ah, makes sense. \$\endgroup\$ – a sandwhich May 11 '11 at 19:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.