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Xingran’s Status Report for 4/3/2021

This week I was able to flash firmware updates to BM83 through OTA. I talked to the BM83 develop team over email and after rounds of debugging I could finally use their Android app as intended; I have also looked into many other programming and controlling options of BM83 along the way.

However, changing the operation modes in the firmware easily made BM83 stop connecting to the Android app, so I think the most reliable option is to have traditional UART update; I also found a GUI tool for sending/receiving UART commands/events to/from BM83, which I think should be our first step to connect BM83 to a speaker. Therefore, I purchased a USB-to-UART converter, so that I can largely follow the BM83 support documents in terms of how I program and config it.

While I am waiting for the converter to arrive, I tested our I2C control interface with the ADC. I can now read and write to the page select register in the ADC, which means that the hardware, I2C protocol and command formats are largely functional; by the time I post this I am still debugging writing and reading other control registers, but I believe it could be done soon.

Looking ahead, I will configure, pair, and connect BM83 to a Bluetooth speaker through the UART control interface with my computer (once the converter arrives). I will debug the ADC so that I can set its control registers, and then I will test its functions by feeding in a sine wave and check the output received by the microcontroller.

If these two things are done, I will officially be developing and testing our main audio path – streaming audio from the ADC input, through the microcontroller, to the BM83 module and then to the speaker.

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Adam’s Status Report for 4/3/2021

REV 1 ASSEMBLY: This week most of my time was focused on Rev 1 hardware assembly in order to get working boards into the hands of my team members as quickly as possible. We decided that the new board (named “Alexey”) with the additional passive components we ordered from Digikey last week would go to Xingran while Sam would get the old board (named “Bernice”) which is still capable of running the UI modules.

By the end of the day on Thursday, I delivered both Alexey and Bernice, as well as a rotary encoder for Sam to test UI code and a power switch. A small amount of work still needs to be done on Alexey to fully implement the Analog Overdrive module, but since this is of secondary importance, we decided to put that off in favor of getting a prototype with a working ADC.

BARI BOX: Meanwhile, I continue to work on the mechanical design for BARI’s enclosure. At present, I can estimate that the cost for 3D printing + fasteners will be on the order of $50 (half of what we budgeted), though I am working on ways to make it lighter and thus cheaper.

I don’t have any good photos this week, so enjoy the remaining parts spread across the floor of my apartment:

And a close up of one of the unfinished boards:

And a suggestive, soft-focus close up for the fans out there 😉