Search found 20 matches

by mathieu
Wed May 15, 2019 11:30 pm
Forum: Pyboard D-series
Topic: Home-made breakout / dev board
Replies: 2
Views: 310

Home-made breakout / dev board

Based on the information from this thread , I designed a very basic development board for the pybd which is documented here . This is actually the first PCB I ever designed, and a big part of the fun was finding out if I could pull off soldering the 0.4-mm-pitch WBUS connectors (spoiler: it's much e...
by mathieu
Sat Apr 06, 2019 4:17 pm
Forum: Pyboard D-series
Topic: Unresponsive pyboard: how to tell if it's dead?
Replies: 6
Views: 482

Re: Unresponsive pyboard: how to tell if it's dead?

A few answers: - This is a pyboard D (PYBD-SF6-W4F2) - I was (foolishly) driving a PAM-8403 audio amp out of the VIN pin of the WBUS-DIP68. I was under the impression that my computer USB could not deliver 1 A :? . - It does look like the fuse is blown (infinite resistance), and the LED lights up br...
by mathieu
Sat Apr 06, 2019 1:32 pm
Forum: Pyboard D-series
Topic: Unresponsive pyboard: how to tell if it's dead?
Replies: 6
Views: 482

Unresponsive pyboard: how to tell if it's dead?

I connect the USB port on my pyboard D to a computer. Nothing lights up on the board; rshell is unable to see the board; no flash drive is mounted on the computer. Same results with a different computer, and with a different USB cable. Pressing USR and RST buttons to enter safe mode gets no response...
by mathieu
Mon Feb 11, 2019 5:26 pm
Forum: MicroPython pyboard
Topic: Changing DAC.write_timed() frequency on the fly
Replies: 1
Views: 143

Re: Changing DAC.write_timed() frequency on the fly

Answering my own question based on a very quick test using a blinking LED connected to the DAC pin... Yes, it seems to work (for the blinking LED at least) by calling Timer(6).freq(f) , where f is the desired frequency. This is (to me at least) unexpected and delightful in its simplicity. I've been ...
by mathieu
Mon Feb 11, 2019 3:39 pm
Forum: MicroPython pyboard
Topic: Changing DAC.write_timed() frequency on the fly
Replies: 1
Views: 143

Changing DAC.write_timed() frequency on the fly

After initiating a DMA transfer from a buffer to a DAC using DAC.write_timed() in DAC.CIRCULAR mode, is there any way to change the frequency at which the buffer is written to the DAC without a new call to DAC.write_timed()? For instance by acting on Timer(6)? My goal would be to imitate some kind o...
by mathieu
Fri Feb 08, 2019 9:51 pm
Forum: Pyboard D-series
Topic: Questions and wish list about Pyboard D
Replies: 35
Views: 2831

Re: Questions and wish list about Pyboard D

Questions: Is there a reasonable chance that the pyboard D would have out-of-the-box support for I2S? Or, conversely, is there any reason to think this is unlikely? Further: am I wrong in believing the micropython implementations of I2S only run on ESP32 boards? If that's correct, is there a technic...
by mathieu
Sun May 27, 2018 12:26 pm
Forum: MicroPython pyboard
Topic: SPI(2) interfering with DAC(2)
Replies: 1
Views: 430

SPI(2) interfering with DAC(2)

I'm using the following: DAC.write_timed(buffer, 16000, mode=DAC.CIRCULAR) on pin X6 to generate an audio signal. SPI-MOSI on pin Y8 to drive a NeoPixel strip with JanBednarik's ws2812 library For some reason, my DAC becomes silent shortly after I call WS2812.send_buf(). I've checked that the DAC bu...
by mathieu
Thu May 24, 2018 10:07 am
Forum: ESP32 boards
Topic: DAC.write_timed() support?
Replies: 1
Views: 458

DAC.write_timed() support?

Hello,

Is DAC.write_timed() supported on ESP32 (more specifically, on the Sparkfun ESP32 Thing)?

I looked for information in the Github source for MicroPython, but didn't find anything.

Thanks,

- Mathieu
by mathieu
Wed May 23, 2018 2:28 pm
Forum: Hardware Projects
Topic: Driver for WS2812 RGB LEDs (NeoPixels, ...)
Replies: 27
Views: 15785

Re: Driver for WS2812 RGB LEDs (NeoPixels, ...)

Great! But as I understand from your post on the other thread, the call to send() is still blocking during transfert, so CPU is not availabe for other tasks. Am I right? Right. First step was to get DMA working, and main reason for that was to get uninterrupted transfers with interrupts enabled. Pr...
by mathieu
Fri May 18, 2018 9:32 am
Forum: MicroPython pyboard
Topic: Fast method for writing to a Neopixel strip
Replies: 2
Views: 531

Re: Fast method for writing to a Neopixel strip

Thanks, I'll try that and report here.