Search found 74 matches

by Mike Teachman
Tue Mar 05, 2019 6:11 am
Forum: Drivers for External Components
Topic: TI ADS1219 ADC driver
Replies: 8
Views: 1110

Re: TI ADS1219 ADC driver

If it is a 24bit ADC and your Vref is 3.3v then the sensitivity it has to read is 3.3v/(2**24) = 0.00000019669532775878905 volts What sort of hardware would be needed to decouple and isolate the ADC so that such fine voltages are not just inducted from the air?? For this ADC the useful resolution i...
by Mike Teachman
Sun Mar 03, 2019 8:34 pm
Forum: Drivers for External Components
Topic: TI ADS1219 ADC driver
Replies: 8
Views: 1110

Re: TI ADS1219 ADC driver

At this time there is no low-cost breakout board available for this device. It is possible to make your own - I added a section to the github repo listing the parts I used.

https://github.com/miketeachman/micropy ... kout-board

ads1219-breakout.jpg
ads1219-breakout.jpg (20.38 KiB) Viewed 1021 times
by Mike Teachman
Sat Mar 02, 2019 12:57 am
Forum: Drivers for External Components
Topic: TI ADS1219 ADC driver
Replies: 8
Views: 1110

TI ADS1219 ADC driver

If you need a 24-bit ADC here is a driver for the Texas Instruments ADS1219

https://github.com/miketeachman/micropython-ads1219

All device functions are supported in this driver. Tested with uPy v1.10 running on ESP32 port.

datasheet:
http://www.ti.com/lit/ds/symlink/ads1219.pdf
by Mike Teachman
Wed Feb 13, 2019 4:41 pm
Forum: ESP32 boards
Topic: i2s compatibility
Replies: 15
Views: 3094

Re: i2s compatibility

I have some questions though, why you decimate or prune your samples before saving into the SD?. And, how can I achieve full resolution (18bits) from the mic (https://cdn-shop.adafruit.com/product-files/3421/i2S+Datasheet.PDF)? There is now a better way to save full resolution mic samples to extern...
by Mike Teachman
Sun Feb 10, 2019 4:12 am
Forum: ESP32 boards
Topic: i2s compatibility
Replies: 15
Views: 3094

Re: i2s compatibility

thanks for trying it out. Really glad to know it works on someone else's build ! For the pruning part, I reduced the sample size to 16 bits to reduce the time to copy the samples to the SDCard (which should help to support a higher sampling rate), and to reduce the space used on the SDCard. In my ap...
by Mike Teachman
Wed Feb 06, 2019 9:46 pm
Forum: ESP32 boards
Topic: i2s compatibility
Replies: 15
Views: 3094

Re: i2s compatibility

Thanks for mentioning this work and listing those devices - I'll have to order some and try them out. The PR I submitted addresses a gap in the functionality of the LoBo port. It is missing a core I2S piece, which is about interfacing to external I2S hardware devices via the ESP32 pins, using the I2...
by Mike Teachman
Wed Feb 06, 2019 8:18 pm
Forum: ESP32 boards
Topic: i2s compatibility
Replies: 15
Views: 3094

Re: i2s compatibility

update: PR for I2S support is submitted: https://github.com/micropython/micropython/pull/4471 usage guide and examples describing how to use this new I2S class: https://github.com/miketeachman/micropython-esp32-i2s-examples It would be great if a few enthusiasts could try out this PR and report back...
by Mike Teachman
Fri Feb 01, 2019 11:11 pm
Forum: Development of MicroPython
Topic: include i2s library for esp32
Replies: 1
Views: 464

Re: include i2s library for esp32

please check out my answer to your esp32 post
viewtopic.php?f=18&t=5900
by Mike Teachman
Fri Feb 01, 2019 3:39 pm
Forum: ESP32 boards
Topic: i2s compatibility
Replies: 15
Views: 3094

Re: i2s compatibility

I'm not aware of a uPy I2S module for the ESP32. For a project that requires an I2S microphone I ended up writing a uPy module that uses the I2S interface in the ESP-IDF. I'll be finishing that work in a couple of days, then submitting a pull request to the main uPy repo. A few things left to do, li...
by Mike Teachman
Sat Dec 29, 2018 6:03 am
Forum: ESP32 boards
Topic: optimizing uasyncio performance
Replies: 26
Views: 3267

Re: optimizing uasyncio performance

As expected, project time "yielded" to holiday time with family and friends ;) But, a few slices of time allowed me to experiment with the Fast IO implementation of uasyncio. https://github.com/peterhinch/micropython-async/blob/master/FASTPOLL.md A time-critical coroutine that handles microphone sam...