Doodads and Whatnot

For a long time I’ve been frustrated by the lack of tools for programming micro-controllers (PICs specifically) using MacOS X. Most bit banging serial programmers wont work with a USB-to-Serial adapter, though I’m told some commercial ones do. There are some USB programmers available but until recently I wasn’t able to find one that was compatible with the 16F88 (PDF, datasheet) and had MacOS drivers available.

Enter the PICkit 2

After finally getting tired of SSHing into a Linux box in another room every-time I wanted to write to a PIC I started looking for a USB based programmer with support for the 16F88. I was pleasantly surprised to see that the firmware for Microchip’s PICkit2 had been updated to work with the 16F88 (as of version 1.20). The PICkit is a nicely made unit (about 10cm x 4cm x 1cm) that can be bought, with a low pin count demo board included, directly from Microchip for under AU$100.

This still left me with the problem of Mac drivers but it didn’t take long to find Jeff Post’s PK2, an open source program for working with the PICkit2.

Using PK2 with MacOS X

Version 2.00 of PK2 works well well with MacOS. Older versions may work too but I haven’t done much testing with them. The program is easy to build and there is a native HID report which means that there is no need for MacOS users to muck about with libusb. Very nice indeed. When building make sure you use the osxhid Makefile target (unless you really want to use libusb). Once built and installed PK2 can be used to update the programmer’s firmware. Everything should be good to go and the programmer should be able to see the PIC it is connected to like so:

tobie@Tea-Chest ~ $ pk2 -device

PK2 version 2.00 - 2006/07/02
 pk2 -device
Communication established. PICkit2 firmware version is 1.21.0

Device ID 0x0760
PIC16F88 Rev 5 found
  Family:         Midrange
  Program size:   0x1000 (4096) words, width 0x3fff
  Eeprom size:    0x100 (256) bytes
  ID location:    0x0
  ID size:        0x4 (4) bytes
  Device ID       0x0760
  Write burst     4
  Program command O
  Program mode    n
  Program timing  n
  Data timing     d
  Erase mode      0
  CP mask         0x0834
  Bandgap mask    0x0000 0x0000
  Config mask     0x3fff 0x0003
  Save osccal     0
  Save bandgap    0
  Command table   63 00 02 03 04 05 06 08 18 17 1f 1f ff ff ff ff

Handy resources

The PICkit 2 comes with a CD-ROM which contains lots of examples and code for the supplied PIC16F690 including several lessons which should help someone not familiar with PIC programming to get a good grasp on the basics. For other PICs there are many forums and mailing lists on the internet including Microchip’s own. A quick Google search should point you in the right direction.

For updates and discussion of PK2 there is the pickit-devel Google group.