Hi.
I’m looking for help, guidance and possibly consultant work to design and develop an amplifier.
Basically I want to build an amplifier with 3 line in inputs and 2 microphone inputs.
Also for every input I need to be able to trigger to which speaker set to send the audio. (Group A, Group B or Group C)
I also want internal storage to store audio files that can be configured to play from various trigger signals.
I figured I will need an MCU for this like stm32. I have some more documentation I can show if necessary
Any pointers to get the ball rolling?
I am willing to pay for help with design and development for a prototype
Thanks.
I’m looking for help, guidance and possibly consultant work to design and develop an amplifier.
Basically I want to build an amplifier with 3 line in inputs and 2 microphone inputs.
Also for every input I need to be able to trigger to which speaker set to send the audio. (Group A, Group B or Group C)
I also want internal storage to store audio files that can be configured to play from various trigger signals.
I figured I will need an MCU for this like stm32. I have some more documentation I can show if necessary
Any pointers to get the ball rolling?
I am willing to pay for help with design and development for a prototype
Thanks.
I basically have a concept idea. I can see if I can upload some illustrations later when I have access to my computer.
Assuming you want to hook specific files/inputs to specific triggers, specific inputs and specific outputs, a programming flowchart is the way to start. We had to do a "very simple" project like this and it ended up needing a Mac mini, a pretty complex program and two 16-channel studio interfaces. There were specific mechanical actions and that was also a microcontroller, but I think it needed I/O expanders beyond the scope of Arduino/ESP32.
We did the amplifiers (LM3886-based) and speakers (a Tang band 2" driver with a subwoofer), with a total of 32 channels and there were about 48 motors that needed activation based on specific inputs and actions. I think a display also ended up in the project due to feature creep at some point, but the program had been handed off due to its complexity (i.e we ended up not doing the software).
But we did start with a flowchart. It would have been impossible to understand the project without.
You'll need to define what constitutes the triggers (this itself can wildly change the product scope), and hook up your controller to a storage HAT where it can look for files. Beyond that, it's better to use a qualified programmer (there are some on the site) to build you a software prototype and see if everything is working before you hook up the noisy bits. I really recommend a Raspberry Pi or similar, as you seem to not have too much I/O but do need local storage and won't need a HAT. Even a model a few years old can do the job.
That’s a great response.
I’m thinking an UI to assign files to maybe some GPIO inputs or something and then you select which speaker group to play the file but not sure if my thinking is correct.
I will make a flowchart to get a better understanding of the project.
I’m thinking an UI to assign files to maybe some GPIO inputs or something and then you select which speaker group to play the file but not sure if my thinking is correct.
I will make a flowchart to get a better understanding of the project.
OK, that's a start.
Copy-paste errors apart, you seem to have each trigger activating only the inputs, but nothing for files or the microphone. Basically a programming flowchart is a list of actions that includes each trigger (on or off), each input, and each output.
For example:
If trigger C is activated play input 2 on speaker 1 unless something is playing on speaker 3 already or microphone input is active. This little loop will be one set of maybe 6-8 lines in code, and there will be a bunch of loops for each action/condition.
The flowchart represents this visually, so you don't have to think in code. Simply in terms of what action leads to what result, and what conditions must be satisfied for that action to happen or not.
At this point it might help to tell us of the use case and the actual application.
Here's an example:
Copy-paste errors apart, you seem to have each trigger activating only the inputs, but nothing for files or the microphone. Basically a programming flowchart is a list of actions that includes each trigger (on or off), each input, and each output.
For example:
If trigger C is activated play input 2 on speaker 1 unless something is playing on speaker 3 already or microphone input is active. This little loop will be one set of maybe 6-8 lines in code, and there will be a bunch of loops for each action/condition.
The flowchart represents this visually, so you don't have to think in code. Simply in terms of what action leads to what result, and what conditions must be satisfied for that action to happen or not.
At this point it might help to tell us of the use case and the actual application.
Here's an example:
Audio inputs is to play audio from other devices through line level. Typically the decision to where to route the audio is decided by the external device with a 0v signal. This is for automatic announcments primarily
Microphone inputs is for dynamic microphones like guide mic/Drivers mic
Auxiliary input is for various signals like door signals or stop signals. for example if the stop button is pressed the chosen file for this function is played.
Microphone inputs is for dynamic microphones like guide mic/Drivers mic
Auxiliary input is for various signals like door signals or stop signals. for example if the stop button is pressed the chosen file for this function is played.
So if I understand correctly, each 0V trigger selects where to route which announcement - announcements come from external devices that provide both the trigger signal and the line level signal (?)
The microphone input is always active and mixed into all outputs (?)
Just these two don't sound like they need a MCU yet, can be done with just discrete electronics. Yet. There must be something you need the MCU for.
The buttons trigger audio file playback from local storage - all outputs, or selective ones? In your diagram in #6 you allude to pin 1 and pin2 controlling , how many such pins will there be? Will they all be the same file, or different ones? Will they all be played only once, or can they be repeated?
One last thing that could help is if you detail each input and output condition separately, and hand that to the designer. A full list of every condition will be required anyway when you start the development.
Good luck, sounds like a very interesting project, I'll be sure to follow.
The microphone input is always active and mixed into all outputs (?)
Just these two don't sound like they need a MCU yet, can be done with just discrete electronics. Yet. There must be something you need the MCU for.
The buttons trigger audio file playback from local storage - all outputs, or selective ones? In your diagram in #6 you allude to pin 1 and pin2 controlling , how many such pins will there be? Will they all be the same file, or different ones? Will they all be played only once, or can they be repeated?
One last thing that could help is if you detail each input and output condition separately, and hand that to the designer. A full list of every condition will be required anyway when you start the development.
Good luck, sounds like a very interesting project, I'll be sure to follow.
Correct
The microphone sends the signal to activate usually by a pressing a button so the same kind of trigger principal for these inputs as above
For these function an MCU is not needed indeed.
For the internal file system and processing it will be.
There will be maybe 5-10 inputs for different kind of applications, In UI i want to be able to pick a file from storage and assign it to any pin so when i for example press the stop button i can program it to play a specific file and how the characheristics should be. (Play once, play when signal goes low etc)
If anybody have som designer referals i would appreciate it tremendously, been looking at Fivver and such but no luck yet.
Either that or i am in for a deep dive and need to lock in with chat gpt 😆