Serial.Read() error: -1

[rohoroho]

Hi, I created the classic MIDI interface. I connected it between my Midi keyboard and the RPI -3.

When I hit a key, the monitor shows for every hit the following error:

serialmididevice: Serial.Read() error: -1

I checked the signal to the serial port with my scope. It looks fine. I have also tried to replave the resistor of 220K by a 100K resistor. But that did not help.

The baudrate in the configuration file I have not changed.

The midi keyboard works fine with other programs.

What can be the problem?

Thanks

[BobanSpasic]

serialmididevice: Serial.Read() error: -1 means a BREAK is occurred.
A BREAK can occur mostly if there is no signal on the line for a long time (for the time of the 8 bits of transmission).
There can be a couple of reasons for something like this:

• voltage levels not matching (3V3 and 5V?)
• baud rate on Pi is set higher than on the transmitting device
• parity settings differs

I would check the voltage levels of the MIDI interface.

[rohoroho]

Thanks for your explanation! The solution Banana71 mentioned, I implemented and that worked!

[Banana71]

Hi rohoroho,

I would check the circuit for soldering errors or shorts. Is the diode reverse biased?
Right RX Pin on GPIO ?
I have had good experience with the following circuit from @diyelectromusic:

[diyelectromusic]

Hi rohoroho,

I would check the circuit for soldering errors or shorts. Is the diode reverse biased? Right RX Pin on GPIO ? I have had good experience with the following circuit from @diyelectromusic:

These days I tend to use the H11L1 version with 3V3 systems like the Pi or Pico :)

Kevin

[rohoroho]

Great! I implemented and that worked! Thanks a lot!