However, you cannot use this feature from cygwin. You need to invoke python script directly from Windows. Double-clicking the python script works, but you need to catch exceptions in the case (otherwise, you don’t know what happened when an exception was raised).
Here is the sample program to read arrow keys.
from msvcrt import getch
print("press ESC to exit")
key = ord(getch())
if key == 27: #ESC
elif key == 224: # special keys (arros, f keys, ins, del, etc.)
key = ord(getch())
if key == 75:
elif key == 77:
elif key == 80:
elif key == 72:
As mentioned in my previous post, AVI Dragon’s SPI pins in debugWire interface have to be disconnected during debug run in order to properly run an application that uses SPI / USI. I also noticed that the Dragon dominates RESET pin, too. In my project, I’m resetting target chip from Arduino. The Dragon is killing this functionality as well. This makes me quite uncomfortable with my development work, so I’ve enhanced the switch I made on bread board previously, and made a helper device. It’s nicely working. I named it “Dragon’s Tail”.
There are several ways to connect Dragon to the target device for debugging. However, only debugWire is available for ATTiny* chips.
debugWire commonly utilizes 6-pin header for ISP (In Circuit Programming).
Dragon can be used both as OCD (On Chip Debugging) and ISP devices. However, these modes cannot be run simultaneously. The device is modal. AtmelStudio has capability to switch modes. In order to close debug mode and return to normal, do debug -> disable debugWire and close from AtmelStudio. This functionality is available only when running debug execution.
AVR Dragon interferes Arduino over USB hub. If you connect both into the same USB hub, serial interface of Arduino eventually freezes. Connect different USB ports to avoid this problem.
Typical analog noise generators make signal by amplifying AC component coming out from zener current of transistors reversely biased between emitter and base (here’s an example circuit).
Any bipolar transistor would work as such a noise source, but noise quality in listening is different from part numbers. 2SC828A is well known as good noise source, but it’s been obsolete for long. So for Analog2.0, I have been recommending 2SC3311 instead. But this part becomes obsolete as well. Now I have to find another one.
I’m going to try making a digital communication bus for synthesizer modules.
Analog synth has a very simple control language which is voltage. Any message is translated to voltage that can be read by any modules that accept voltage input. So for example, VCO output is basically audio output but also can be used as control voltage of some other modules, such as VCO cross modulation.
This simple data exchange methodology makes analog synthesizer very versatile and flexible. However, as a drawback, patch wiring would become too complicated as you make complex module network.
One solution for making the wiring simple is to use a single common data bass where all modules are connected, and exchange data selectively using some software. Apparently, making such a bass for analog signals is impossible or extremely difficult. So I’m going to try making it using a digital bass.
I did basic study of voltage controlled envelope generator based on analog circuit approach. However, I found the implementation quite complex, although its quality was good. So, I next tried another approach that has simpler circuit. This version calculates the EG curve using micro processor, and makes analog output using PWM with minimum external filtering circuit.
I’ve started studying voltage controlled envelope generator designs, since I have several use cases of it.
An envelope generator usually is implemented by an RC charging circuit with potentiometers as resistors. However, such design does not capable of quick parameters change. So voltage control (or digital control) functionality is necessary for better articulation. Also, non-potentiometer control is crucial to polyphonic voices.
There are several approaches to design voltage controlled envelope generators. This article describes about an analog approach which I tried first.