9/13/24
Drawing:

To Do:
- Decide on input and output for each module in design with team
- Continue envelope research, create first rough sketch of amplitude envelope circuit
- Test out arduino input and output, decide on what will be digital/analog with team
- research and decide on a direction to go with the DAC
9/22/2024
Last week the team got together and did some testing with an Arduino, figuring out how to use the timer interrupt and output a square wave onto the oscilloscope. We then decided to go with a Teensy rather than Arduino as the clock speed will fit our needs better. We ordered parts and managed to get an output from the Teensy using the built in DAC. It looks like we will still be using a separate DAC for performance purposes. I have been researching an envelope IC and how the envelope circuit will be integrated with everything else we have set up. This week I will be
- Working on the envelope schematic, specifically trying to understand better what parameters with IC needs and what it can do.
- test how the envelope will be controlled and how the input is translated into the circuit.
- Work on the CDR presentation
My concerns currently are mainly that it is hard to break up parts of the project to work on in parallel in the team as everything is so dependent on each part.
9/29/2024
Yesterday I updated our teams block diagram, illustrating changes to our design and added more specific information based on component decisions we have made.

I have been working on getting a circuit design put together with the Envelope IC we have decided on using. So far I have the 3 of the input parameters set up, Attack, Decay, and Release. These 3 Parameters all will be controlled with potentiometers that will be given -5 volts, followed by a voltage divider that steps that down to the 0 to -240mV that these parameters need to input into the IC. This week I will be working on the sustain parameter as that is a bit more complicated as it needs to be based both on a potentiometer but also the gate of the note.
1/26/2025 Worklog
This week I worked on researching a new plan for the Envelope module of our Synth design. The Ic we were using wasn’t working as reliably as needed so after trying a few more things, we decided to try a different design. I ordered a 7555 timer ic that is used in an open source design of an ADSR envelope by YUsynth and Eddy Bergman. I found parts and had them ordered. This week I will be looking more into this design for considerations that will have to be made when putting it together and integrating the envelope into our Synth.
2/4/2025 Worklog
This week I got in the parts for the envelope module with the new design we are using. I started assembling it on a breadboard, but have not gotten to the point of testing yet. Next week I will be spending time getting it testable and hopefully working. If I can’t get it working this coming week, I will start switching to a digital envelope design.
2/16/2025 Worklog
This last week, we continued working on the analog envelope module. We ended up deciding to go with a full DSP design as we couldn’t get an analog design working given our time constraints. We currently have an envelope design working with the teensy audio shield. This week I will be updating our KiCad schematics to fit our current designs and start working on the PCB design.
3/3/2025 Worklog
Last week I started working on the schematics and board design for our current setup. This week I will continue working on that and hopefully get to a point where I can have other look it over. We will have to make decisions about the UI connectors for the envelope and filters on what will be sliders and what will be knobs. I am wanting to get our first version of the board ordered by next week so that will be my main focus.
3/9/2025
Last week I have been working on the pcb design. It is not done yet as the weather last week impacted my ability to get on to campus. I do however have all the footprints for the components into KiCad and now we just need to move some stuff around and add in connections. This is what I will be working on this week. We also need to consider how much space the sliders will take on a PCB and if it might be worth it to create a separate board to house those.

3/16/2025
Last week we finished up the PCB design, we decided to put the UI components on the top side of the board and the other components on the bottom side. We did this because we want the sliders to be able to be flush with the top of the box, but the teensy with the audio shield on top is taller than the sliders. This week we will mostly be focusing on box designs and prepping the PCB design for a second version if needed just in case as we will not have much time left to redesign if it doesn’t work for some reason.


3/23/2025
Last week we started the case design and went over some considerations for how we want the final enclosure to look, as well as how we want to implement the board standoffs. We are currently just waiting for our board to come in as getting that working and in the box is our last step.
3/30/2025
Last week our PCBs came in and we got the components all soldered. We also finalized our case design and printed it. This week we will be making some final touches and testing, then our project will be complete.
