These are my various projects, mostly to learn by doing. Somewhat in chronological order.
Here's an example of why one should not stay in the starter kit phase for too long. I didn't have any material to work with, didn't know about Dupont headers, ribbon cables or breakout boards. It's very frustrating to solder directly onto header pins as they take longer to heat up and the plastic will distort. Also, I only had a few header scraps and was hesitant to use even those. By buying a reasonable supply of material you'll be able to more feely experiment and learn faster.
Hadn't used this display until... this exact date. It's a bit wonky when updating pixels. Made for 5x8px characters that you can define yourself. There's a driver onboard under a black "glob-top" (I believe that is the technical term).
Using a shift register to control a single 7(8) segment display. The micro controller only have so many pins for controlling LEDs and such, but there are ways to transmit more complex information over just a few pins (perhaps a single one).
Buck converter something something. Here my bench power supply powers another one which modifies the voltage. Stay away from working directly with AC / wall outlet if you're a beginner!
Accident. Or was it murder? LEDs need a resistor or they will easily fry.
A DIY kit I soldered together. Cheap audio amps aren't very good, but practice is. Headers went on skew, despite efforts to hold in place with greenstuff. The actual trick is to solder one lead sloppily, then with a hand free you can now reheat that joint and click/adjust the header into place. When perfect, do the rest of the joints. If you solder two joints before adjusting you're in trouble as you can't reheat both.
This audio amplifier module also uses the LM386 (though surface mount) I believe. Quality is not very good. Audio signals need good caps... the pillow-shaped poly*, I've heard. Ceramic caps can apparently work as microphones, I guess because capacitance varies with pressure, and also as speakers, producing a high pitch whine. To complicate matters further, wires pick up radio signals, and twisted/touching wires do weird things as well. In these SMD boards I guess the tiny caps (brown bits) are not sufficient.
Paper breadboard can be easily cut. This is an early version of a purring machine for my cat. Put in tennis shoe and it sounds like cat-mom. Sleeps next to it for hours. Will make over-engineered version when new parts arrive.
Not a project, but I love the look of these.
My first ATtiny85 project. It's a power light pulser for a mac G4 MDD, to replace the onboard one. Ultimately I just used a rainbow LED though...
555 blinky thing (barely) powered by my very old solar panels, through a step-up.
Audio mixer with its potentiometer guys showing. I bought this mixer back in the Amiga days, meaning to use it for mixing the separated 2+2 channels onto tape. Never got it to work. I was worried that I had reversed the polarity of the PSU and blown something. The enclosure was hard to open up so I didn't bother trying to fix it... until now. Turns out the bottom has nothing attached to it so it can be pried off. No need to undo all of knobs and plugs. Once inside I noticed a protection diode, which measured OK, so probably nothing wrong with the mixer.
So I tested PSU (wall wart) and got no voltage from it. Opened that up (it was welded >__<). The rectifier bridge measured OK, Cap was OK, but it had a variable transformer coil which failed continuity test. Unclear to me how these simple things can fail, but it was one of those custom things with leads coming out at different points (for 3-12V output). The mixer takes DC9V through a barrel jack or 9V battery underneath, but to test it I first had to solder up a RCA-Stereo plug cable.
It works, though noisy at lower volume. Rectangular LEDs come on at higher volumes as a form of VU meter.
I replaced the black power button with a red to give it a sexy accent, and even got a set of replacement (aluminium) knurled shaft knobs.
Decided to take the bull by the horns and assembled my DSO oscilloscope. Here I've only attached the resistors... 23 to measure and place. Still have no good method for bending legs to make 'em stay put.
DSO oscilloscope finished. Was surprised when it worked, because I had to do some SMD repair on the fragile screen ribbon (C8, C9: 1uF). Last image: measuring a 555 "square" wave signal generator I made.
Old legs can serve again, as breadboard jumpers. Here I've used shrink tube as isolation/color coding, but old cable peelings can work in a pinch.
Bought a cheap LCD screen with composite in from china, but it rolls when hooked up to NES/SNES. Gets hot too. Seems to have been repurposed, as the board had been forced into the casing and had no buttons mounted. I made my own breakout cables just to poke around. With China, you'll never know what you'll get, but the advantage is that you're no longer scared to open things up and begin shorting pads to see what happens.
LED experiments. Trying out the resistor networks, testing for LED dimming as they go on and off.
Laying out my Arnuino. Soldered new headers onto LED tester board.
If your budget is really tight, you can make a simple (and perhaps not very safe/rugged) variable power supply from an old 12V power brick and a cheap step-down buck converter (<2€). It might be enough for simpler low power things. Then you can make an enclosure for the brick and board (or just board if brick gets hot), swap out the buttons/trimpots for front panel mount ones. Add a toggle power switch for AC in, and a latched one for DC out. Though, if you buy all that, you're up to the cost of a cheap bench one already (except you get some extra components and the pleasure of building something). Project is... underway.
A much simpler solution for simple breadboard stuff is to use the <1€ breadboard power supply. I also found a little power supply hidden under a breadboard listing (8€). It's a step up from the breadboard one, but a step below a bench PSU. I suspect cheap power supplies won't handle abuse as well as bench ones. Above I'm powering a power supply with a power supply, which is a bit of nonsense. Discovered later that leaving the 9V battery connected drains it :/ I should get these battery boxes with a built in switch.
More chip pics. Building a project box for buck converter board. Should have done front panel art first, printed and used as guide.
Found 12V in an IKEA LED strip hub dangling and attached a little auxiliary light for my corner workspace. I had some "super bright" white F3 LEDs which I put in series and parallel (4+4). They drop two point something V each. Velcro-tape came in handy for attaching the precariously dangling hub to a shelf side.
New Panasonic microswitches replacing the busted ones in this old Amiga tank mouse. Can be twisted to sort of fit. Different height too, so had to modify the plastic contacts a bit. 6x6 Tactile switches fit better but they're not "clicky".