Search found 20 matches

by rezarethink
Thu Nov 16, 2023 6:16 pm
Forum: ESP32 Arduino
Topic: Unwanted delay before and after SPI transaction
Replies: 5
Views: 6914

Re: Unwanted delay before and after SPI transaction

This worked for toggling the CS automatically SPI.begin(SPI_SCK, SPI_MISO, SPI_MOSI, SPI_SS); // SCK, MISO, MOSI, SS SPI.setHwCs(true); However, it didn't result in a speedup of the overall SPI process. I measured 3uS before the SPI transfer and 6uS after the SPI transfer worth of delay when the SPI...
by rezarethink
Thu Nov 16, 2023 4:44 am
Forum: ESP32 Arduino
Topic: Unwanted delay before and after SPI transaction
Replies: 5
Views: 6914

Re: Unwanted delay before and after SPI transaction

I’ll test it out and see if that speeds anything up. I found some docs that discussed a 1us delay acquiring a bus but I’m seeing a much larger delay.
by rezarethink
Thu Nov 16, 2023 3:30 am
Forum: ESP32 Arduino
Topic: Unwanted delay before and after SPI transaction
Replies: 5
Views: 6914

Re: Unwanted delay before and after SPI transaction

That’s what the example code did. Is there a faster way?
by rezarethink
Wed Nov 15, 2023 6:04 pm
Forum: ESP32 Arduino
Topic: Unwanted delay before and after SPI transaction
Replies: 5
Views: 6914

Unwanted delay before and after SPI transaction

https://previews.dropbox.com/p/thumb/ACHqZ7Fbn9pHOj3AmNwI3_XGYisd-u_ivTBdktcYmZhL-cviEUketfyo7R-2xnnpjcMFnt-Rq6m6aWcK539zdjBGE0Q4SbV_gsj9J6oiCRfczgKYPPHfJodeVG3mG7vEPfZdeu5oNV6hO5Tgj2vMUGngE6dEV_v00B5uX3PP-mJButK4BGYibBJHBWWXeUJKBF2Ix9MhPYuPQZ8rVzxyxf5NXrt5rpQwF9A91fDs7BUVZxWBGjU0RyCCJ8B0aVjsNTY_OV...
by rezarethink
Mon Nov 27, 2017 10:22 pm
Forum: Hardware
Topic: What matching components should be used for the 5x5 QFN package?
Replies: 9
Views: 15316

Re: What matching components should be used for the 5x5 QFN package?

Although the sparkfun schematic might have those components in it, they only populate a small cap on the PCB, which is strange. Also, the sparkfun uses the 6x6 package and we use the 5x5 which has a different rated output impedance. There are references for the components used to match the 6x6 but n...
by rezarethink
Thu Nov 02, 2017 5:01 pm
Forum: Hardware
Topic: What matching components should be used for the 5x5 QFN package?
Replies: 9
Views: 15316

What matching components should be used for the 5x5 QFN package?

According to the datasheet, the smaller 5x5 QFN (ESP32-D2WD) part the output impedance is 35+j10 which is different than the larger 6x6 package. What matching components would be recommended that part vs the old part (which has a different output impedance)? Also, I noticed that there are no matchin...
by rezarethink
Wed Sep 13, 2017 3:43 am
Forum: ESP-IDF
Topic: C version of esptool?
Replies: 3
Views: 6734

C version of esptool?

I will have an ESP32 and an STM32 on my PCB. I need to be able to perform OTA upgrades to both. Wondering if there is a C port of the esptool that will allow me to reflash the ESP32 from the STM32? The ESP32 that I'm using only has 16mbit of flash (internal) but the STM32 has 64mbit. Planning on hav...
by rezarethink
Thu Aug 24, 2017 2:59 am
Forum: Hardware
Topic: JTAG Daisy-Chaining
Replies: 1
Views: 4610

JTAG Daisy-Chaining

I'm planning on using the ESP32 along with an STM32. Is it possible to do JTAG daisy-chaining? And would both ICs need to be powered up for JTAG to work for either IC?

Thnx,
Reza
by rezarethink
Thu Aug 24, 2017 1:50 am
Forum: Hardware
Topic: Crystal Capacitance Tuning
Replies: 1
Views: 5837

Crystal Capacitance Tuning

I've been able to use a 26Mhz and 40Mhz xtal in testing, but for production if 40Mhz is more supported, that's what I would like to design in. I'm considering this XTAL: http://datasheet.octopart.com/FA-128-40.0000MF10Z-K3-Epson-datasheet-86700903.pdf For other designs, I typically double the capaci...
by rezarethink
Wed Aug 23, 2017 5:58 am
Forum: ESP-IDF
Topic: JTAG (OpenOCD) with WinBond Flash Works, Fails with Macronix Flash
Replies: 3
Views: 6590

Re: JTAG (OpenOCD) with WinBond Flash Works, Fails with Macronix Flash

I'm asking everyone - spent 3 days on this so far so I'm looking for all the help I can get. :) I just got a reply from visualGDB saying that they were previously using their own version of openOCD with their own flashing stubs in it. The latest beta version supports the esp32 version of openOCD and...