small-scope

I've built the new board and tested some features. Have to visit local hackerspace to do more tests.

Conclusions:

• DC works
• attenuator works
• attenuator values are really impractical (not very standard) and I'll probably have to buy them online

To do:

• test AC (need AC source)
• test DC offset (need 10k or similar pot)
• test overvoltage protection (need 9V source for arduino)

I've compiled the scope in windows 7 virtual machine as well and that went without any problems, so after I test the board I'll probably add windows executable to github.

Today the new PCB design is finished. I'm quite satisfied. It's probably not my finest work and the PCB area is larger than necessary, but it's single sided with only two short leads on top layer of the board.

I haven't made and tested the board yet, and that will probably have to wait at least until next week.

For the moment, this is it, and if the board works as intended, I'll probably call this project finished and start something new.

So today the schematics got an update. This should be more or less final form for the moment, no more feature creep.

Next thing on the schedule is designing PCB which will take a bit of time since I want to stick with single layer design friendly to home PCB manufacture.

The features now include attenuator, AC coupling with offset, DC offset, some safety, two LEDs for status...

As before, this is still in development and hasn't been tested, so I don't know whether it actually works, but to best of my knowledge, it should.

I had to move to a different apartment and was lacking internet access so all the projects took a hit.

Progress should continue soon.

The PCB design is done. It has attenuator and some protection so my goals are met. Added the option to run the scope from external power supply as well, and fixed the missing Vref cap on current version.

Haven't had opportunity to make the board yet, so i have no idea whether it actually works (to best of my theoretical knowledge it should).

Most of the software is done(ish).

The firmware works decently, I'll probably rearange it at some point (put different pieces in different places). Just ironed out a bug/feature today.

The software is never done, but it's in good enough state, it works and it looks fine. It lacks some features I'd like to add.

The hardware is the main issue at the moment.

I have a "working" version based on girino, but that has some problems (well, mine has). First, I'd like an attenuator on input and some protection for arduino. I've modified some of the OP amp parts as well.

Currently I'm unable to make PCBs so the work si purely theoretical, but that should be resolved soon.