Archive for January 22nd, 2019
With the astable blinking green, I had to do this:
It blinks every two seconds because it uses 1 MΩ timing resistors, rather than the 2 MΩ resistors in the first version.
Because the DSO150 runs from the internal battery, you can clip it anywhere with few ill effects. The blinky runs from a battery, too, but connecting a high-impedance node to what’s basically the power line common may lead to heartache and confusion; it’s generally a Bad Habit.
A closer look at the DSO150 screen shows the expected bipolar exponential waveform across the 1 µF timing cap:
The scope triggering seems iffy, as the trace capture pauses every now and again for no apparent reason. This may have something to do with the very slow sweep speed; at 500 ms/div, the complete waveform takes forever to accumulate.
At least we know the signal lies well within the DSO150’s bandwidth!