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by PeterR
Sun Jan 10, 2021 10:43 pm
Forum: General Discussion
Topic: How to use SPI of esp32 to read ADC samples periodically with fixed sample rate?
Replies: 5
Views: 1721

Re: How to use SPI of esp32 to read ADC samples periodically with fixed sample rate?

You will find this hard to impossible with an ESP depending on exactly what other I/O etc you use. The ESP has bus contension issues. Now the above does depend on if you can tolerate occasional (say) 2mS drop outs. 400 KHz ->25 uS. AFAIR it takes 10 uS+ to set up a SPI DMA. You could pre-allocate th...
by PeterR
Sun Jan 10, 2021 10:22 pm
Forum: General Discussion
Topic: SD card with SPI adapter
Replies: 6
Views: 1871

Re: SD card with SPI adapter

20 Mhz seems a lot. 10 Mhz might be pushing it. Unfortunately there are a lot of clone cards. I developed a product with an SD card & during reasearch bought many cards from a variety of suppliers from Amazon, ebay etc. Each supposed OEM card bought either at different times or from different suppli...
by PeterR
Sun Jan 10, 2021 10:10 pm
Forum: General Discussion
Topic: ESP32: Guru Meditation Error: Core 1 panic'ed (StoreProhibited)
Replies: 1
Views: 150

Re: ESP32: Guru Meditation Error: Core 1 panic'ed (StoreProhibited)

All the line numbers are posted, so post the source files! On a 30 second scan I could not see any pointer use, no mallocs etc & 9 out of 10 exceptions are stack related. Bump your stack. If that still sucks then post the source files, like C:\Users\Tom\Documents\Arduino\libraries\FastLED-3.4.0\src\...
by PeterR
Wed Jan 06, 2021 6:27 pm
Forum: General Discussion
Topic: New user issues with ESP32 and a SD Card Reader
Replies: 9
Views: 348

Re: New user issues with ESP32 and a SD Card Reader

Some code might help! I have used an SD card on ESP32 (using a hacked Ardunio driver) without issue - and I test hard. My only 'quick win' thought is that you should wind SPI clock speed back to say 1 MHz and then work up. ESP32 peripherals are slower than you might expect & GPIO muxing does not hel...
by PeterR
Thu Dec 31, 2020 11:32 pm
Forum: General Discussion
Topic: ESP32 GPIO Input Hysteresis (Schmitt Trigger)?
Replies: 4
Views: 357

Re: ESP32 GPIO Input Hysteresis (Schmitt Trigger)?

Not tried TWI on ESP before. SPI should do it. You can figure the mode. Some edge cases on hard wiring CS to figure but doable. Trouble is you have 4-6 asynchronous sources & you do not have 6 SPI devices on the ESP. 25MHz is also probably too fast if you use the ESP GPIO mux (use non native SPI pin...
by PeterR
Tue Dec 29, 2020 10:29 pm
Forum: General Discussion
Topic: ESP32 GPIO Input Hysteresis (Schmitt Trigger)?
Replies: 4
Views: 357

Re: ESP32 GPIO Input Hysteresis (Schmitt Trigger)?

You should really describe your original problem along with question.
No schmitt but a software latch, counter, RMT might work just as well (depending on you're actual problem).
by PeterR
Wed Dec 23, 2020 4:32 pm
Forum: ESP-IDF
Topic: Issues when using SPI SD card
Replies: 10
Views: 1024

Re: Issues when using SPI SD card

Well the datasheet says that it has a level convertor but does not show you how to use 3.3V.
I would hunt for a tutorial.

If you run 5V into an ESP pin then the ESP won't love you for long.
by PeterR
Mon Dec 21, 2020 1:30 am
Forum: General Discussion
Topic: MQTT connection fails when using static IP
Replies: 1
Views: 211

Re: MQTT connection fails when using static IP

The MQTT over web socket assumes that everything is in a single ethernet packet as I recall. If you are using websockets then check my posts, there is a patch in there somewhere. Perhaps the same issue exists with other transports? There is not enougth in your log for me to work with. Why the first ...
by PeterR
Sun Dec 20, 2020 10:03 pm
Forum: General Discussion
Topic: I2C Fails when doing SPI FLASH
Replies: 1
Views: 209

Re: I2C Fails when doing SPI FLASH

Hi, Yes, I suspect this is an inherent device issue. (1) ESP32 internal flash write will block code cache fetching - If your I2C driver is not located in IRAM then the driver may/will block. Simple answer is IRAM your I2C driver. There is lots of IRAM free these days & being 32 bit addressable its h...
by PeterR
Wed Dec 09, 2020 1:38 am
Forum: General Discussion
Topic: Implementation of the printf() function
Replies: 3
Views: 468

Re: Implementation of the printf() function

I direct ESP_LOGx to UDP and that works fine. I do see some 232 corruptions from time to time though but hey that's 232. printf() is not declared as RT safe (its pre C++11 for a start) & so you might well see RT issues! I think you are looking quite deep. Why debug that deep when you could roll your...

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