Hello everyone !
My first time posting a thread here, hope I won't break any rule ! (don't hesitate to tell me
)
I play in a band and we use MIDI to control our pedalboards. My goal is to create a solution to run MIDI over more than the 15m limit.
I saw this schematic about building a MIDI Line Driver over Cat 5 : https://www.edn.com/send-midi-signals-over-long-distances/
So I recreated the schematic in EasyEDA and worked on the PCB to make it work.
Four questions :
- Do you think I did anything wrong in my PCB or in my schematic ?
- On the schematic, I don't really understand the role of R3. Is it some kind of biasing of the signal between the 4N25 optocoupler and the input from the 74LS07 ?
- LED receive and send are supposed to show MIDI Data activity but I don't understand the setup with the +5V input on one side of the LED and the 74LS07 on the other side, could someone explain this to me ? (or point me to the right direction to understand this by myself ?)
- On the original schematic, there's C4, a 100nF cap between +5V and Ground, I thought it was just for stability improvement but with my power supply design, I think I don't need it anymore, am I right ?
My questions are probably quite basic but I'm learning all by myself so obvious things are sometimes not that obvious for me
Have a nice day everyone, thanks !
Arthur
My first time posting a thread here, hope I won't break any rule ! (don't hesitate to tell me
)I play in a band and we use MIDI to control our pedalboards. My goal is to create a solution to run MIDI over more than the 15m limit.
I saw this schematic about building a MIDI Line Driver over Cat 5 : https://www.edn.com/send-midi-signals-over-long-distances/
So I recreated the schematic in EasyEDA and worked on the PCB to make it work.
Four questions :
- Do you think I did anything wrong in my PCB or in my schematic ?
- On the schematic, I don't really understand the role of R3. Is it some kind of biasing of the signal between the 4N25 optocoupler and the input from the 74LS07 ?
- LED receive and send are supposed to show MIDI Data activity but I don't understand the setup with the +5V input on one side of the LED and the 74LS07 on the other side, could someone explain this to me ? (or point me to the right direction to understand this by myself ?)
- On the original schematic, there's C4, a 100nF cap between +5V and Ground, I thought it was just for stability improvement but with my power supply design, I think I don't need it anymore, am I right ?
My questions are probably quite basic but I'm learning all by myself so obvious things are sometimes not that obvious for me
Have a nice day everyone, thanks !
Arthur
