I have build a stepped tone generator (aka Atari Punk console) which are 2 555 timers connected together (one 555 is configured as a astable oscillator and drives the second configured as a monostable oscillator; more info here).
The circuit works as expected (I am using a 556 in place of the two 555).
I would like to control the frequency of the 555s from a midi keyboard. For this I would like to use a MIDI to CV converter that translates midi signals to voltages. I also build this circuit, which is based on an arduino and 2 DACs (MCP4922) and works as expected. (I can control another analog synth with it).
However, if I connect the MIDI to CV converter to the CONTROL pin of the 555, it does not work: whatever the output of the DAC, I measure around 5V on the CTRL pin. I believe this comes from the fact that the CONTROL pin of the 555 is at a voltage of 2/3 Vcc by default. How can i control the voltage applied on the control pin of the 555s with such a system ?
I am relatively new to electronics and this might be a complete newbie question. I am sorry if this is the case but I could not find the answer anywhere on the internet.