PicKit 3

I've had a long lay off from electronics, but the bug has bitten again. I wanted to drive some small motors at variable speeds. The way I would have tried in the past would have been to try using pulse width modulation from a Microchip PIC pin to create the pulses to drive a motor. The motor draws too much current to drive directly from a PIC pin, but a transistor or a half bridge would be fine, either using the PIC pin to control the motor.

I dug out the PIC chips I could find and looked on-line for datasheets etc. I found some PIC16F873 chips - t'Interweb informs me that these are out-of-date, but I thought I'd have a go anyway.

In the past I would have used Microchip's MPLAB to create the code for the PIC chip. The code would have been PIC assembler for their mid-range chips. I would then have copied the compiled code (as a hex file) to a program supplied by Velleman that used their K8084 PIC programmer to write it out to the chip. I never used the assembler enough to get properly familiar with it, so it was always an error-prone struggle that put me off a bit. All of this software expected to run on Windows which I am very happy to have moved away from onto Linux, so there is a another problem. Lastly the Velleman board connects with a serial cable (not USB) and it seems that a USB to Serial converter does not work with it.

I have since discovered Arduino. It uses USB, can be powered by the USB, has a C compiler that run in an IDE on Linux and works very well. Uploading the code to the Arduino is simple via the USB connection and the serial connection allows communication between the PC and the board. Arduino is easy to use and seems very popular, it does seem to be a bit of a one-size-fit-all. The chip usually comes pre-installed on a board with the external connections presented around the edges. Arduino is more expensive than a PIC and there are hundreds of PIC devices to choose from. I think the idea of using a PIC and Arduino in suitable places seems interesting too.

While I was looking at all of this I noticed that Microchip have ditched their in-house development platform and moved to Netbeans. This is an IDE I have used before. It works well so I thought I'd try it out. A download and install later and I could now assemble PIC code on my Linux PC, so the first Windows hurdle was overcome. Then I discovered that the Velleman PIC programmer didn't work - I think some of my soldering of the kit has let go. I looked for what the modern way of programming PICs (even my old ones) would be and discovered PicKit3. It is a programmer and debugger from Microchip which integrates nicely with the new Netbeans IDE, which they now call MPLabX. I found also that there are clones of PicKit 3 available so I ordered one from a Chinese company. It came with a Zero Insertion Force board for a range of chip sizes to plug into the PicKit 3 so plain PIC chips can be programmed.

So all that remained was to find a C compiler for PIC chips. As I looked through the literature on-line I discovered that Microchip have just released a new compiler called XC-8 for the mid-range PIC chips, like mine. The basic option is free. I have just downloaded it and installed it on my laptop into MPLabX, so now I need to try it.