What was your first electronics project?

That's a great question. I'm sure a bunch of my first experiments where just hooking things to a battery and a switch, or putting together circuits from a "learning kit" onto a breadboard, so I won't be counting those.

I think my first, actual, real project was building a PIC programmer. It's one of the first PCBs I remember etching, and the first time I remember following all of the steps to a project, from researching several alternatives, selecting the best fit for my needs, gathering the materials, instructions and tools, all the way to completing an actual assembled gizmo that had a purpose.

It was an "Enhanced" NOPPP3 programmer, and I built it after someone recommended me to look into Microchip PICs (they knew I was passionate about programming and electronics, so they introduced me to microcontrollers and in the process casually changed my life).

One of my favourite projects used a PIC chip, the one with four A-to-D converters on it plus a useful number of digital I/O's. I wrote the program in Assembler, which was so simple it seemed hardly worth using a higher-level language. The circuit contained the PIC chip, a ceramic resonator, a capacitor or two, and some pins to solder the wires to. The Veroboard fitted into about the smallest aluminium box available, with a 9-way D connector on each end, one male and one female. The purpose of this little box was to convert the analogue voltages from a two-axis analogue joystick into the variable-frequency quadrature square-wave signals required by the mouse port on the BBC Microcomputer. This meant I could use a proper joystick to fly aeroplanes on the Beeb! The little box is powered from the Beeb, so no external power supply is needed. I was never happy flying with a keyboard...

The great thing about doing it with a PIC was that the box replaced several up/down counters, two full-sized A-to-D converters, a clock circuit, digital interfaces (opto-isolated?), a few other bits and pieces, and yet another PSU. Three push-buttons replicate the three buttons on the BBC mouse. Using individual chips and discrete components to do the job, plus the power supply, would have required a container about the size of an AVO Model 7 multimeter (est) but much lighter.

I would have liked to have used the PIC range for work projects but I don't think MicroChip made them to military specifications at that time.

I love when PICs (or any other microcontroller) can replace a bunch of other ICs. Before I used PICs I was using logic gates and converters, and counters. It was mind-blowing to me that all of that could be replaced with a single IC that I could program to my liking.

I definitely like the simplicity of PIC assembly (at least for the earlier family of devices. The new ones are fairly more complex) and I also enjoy writing code directly in assembly instead of going for a higher level language.

battlecoder said:

I love when PICs (or any other microcontroller) can replace a bunch of other ICs.

Yes. There is an ever-returning cost though: you usually have an additional manufacturing step to program the device.

Yeah. Mind-blowing to me too. After the A-to-D-to-Quadrature I made a digital selector switch using two CMOS logic chips so that I could select either the digitsed joystick output or a genuine mouse output at the flick of a two-pole changeover toggle switch. This saved lots of plugging and unplugging, which is always a good idea where mini-DIN connectors are being used. One pole of the switch was connected to the Chip Enable pins, the other to the Vcc pins. I did that to prevent overloading of the 5v supply from the BBC mouse port; it probably wasn't necessary.

Yeah. Mind-blowing to me too. After the A-to-D-to-Quadrature I made a digital selector switch using two CMOS logic chips so that I could select either the digitsed joystick output or a genuine mouse output at the flick of a two-pole changeover toggle switch. This saved lots of plugging and unplugging, which is always a good idea where mini-DIN connectors are being used. One pole of the switch was connected to the Chip Enable pins, the other to the Vcc pins. I did that to prevent overloading of the 5v supply from the BBC mouse port; it probably wasn't necessary.