Search found 7 matches

by ZaneKaminski
Wed Apr 20, 2022 2:46 am
Forum: Hardware
Topic: ESP32 SPI /CS setup time before first SCK pulse?
Replies: 2
Views: 1785

Re: ESP32 SPI /CS setup time before first SCK pulse?

mikemoy wrote:
Tue Apr 19, 2022 4:05 am
Did you check the docs?
Yes I have, but there is no relevant information. So presumably there is no configurable parameter for this but I nevertheless need to know the delay between /CS going low and the first SCK pulse.
by ZaneKaminski
Mon Apr 18, 2022 11:17 pm
Forum: Hardware
Topic: ESP32 SPI /CS setup time before first SCK pulse?
Replies: 2
Views: 1785

ESP32 SPI /CS setup time before first SCK pulse?

I am interfacing the ESP32 as an SPI master to external logic at 80 MHz. I need to know, on the ESP32's SPI master operating at 80 MHz, how much time passes between /CS going low and the first SCK rising edge? Is this parameter configurable?

Thanks for any help you can provide.

Zane
by ZaneKaminski
Sat Aug 26, 2017 6:04 pm
Forum: Hardware
Topic: 26MHz TCXO (not crystal) -- which pin to connect to?
Replies: 10
Views: 17977

Re: 26MHz TCXO (not crystal) -- which pin to connect to?

I would also like to connect a 40 MHz clock generated elsewhere in my system to the ESP32. Hassan789, I think a 1.8V signal would probably be too low. It's likely a 3.3V level. Anyway, it's difficult to say whether it should be connected to XTAL_N or XTAL_P. Other chip vendors use a naming conventio...
by ZaneKaminski
Thu Jun 08, 2017 8:33 pm
Forum: Hardware
Topic: ESP32 GPIO slew rate/risetime
Replies: 9
Views: 9704

Re: ESP32 GPIO slew rate/risetime

Thanks for the info on the drive strength. That was a recent post! I shouldn't have missed it. Anyway, if nobody has any figures for the edge rates, I'll eventually measure it over all the drive strengths and with a few different capacitive loads My current design with the ESP-WROOM-32 is all quite ...
by ZaneKaminski
Mon Jun 05, 2017 9:45 pm
Forum: Hardware
Topic: ESP32 GPIO slew rate/risetime
Replies: 9
Views: 9704

ESP32 GPIO slew rate/risetime

Can anyone say anything about the rise and fall times of the I/O pins on ESP32? Is there a way to adjust the slew rate or drive strength as on other MCUs?

Zane Kaminski
by ZaneKaminski
Sun Mar 12, 2017 11:44 pm
Forum: Hardware
Topic: Clarifications on strapping pins
Replies: 1
Views: 5597

Clarifications on strapping pins

The following table is included in Figure 2 in the ESP32 datasheet: Screen Shot 2017-03-12 at 5.36.52 PM.png I am not sure how to interpret this type of truth table. It it saying that both GPIO0 and GPIO2 have to be low to download the boot image? What happens when GPIO0 is low but GPIO2 is high? I ...
by ZaneKaminski
Sat Jan 28, 2017 11:44 pm
Forum: Hardware
Topic: I2S - output main clock to codec
Replies: 2
Views: 6604

I2S - output main clock to codec

Hello. I have reviewed the I2S driver API found in i2s.h, but I am still not sure about one detail. I need to output the a main clock (16.9344 MHz or 18.432 MHz) to my codec chip. I figured I would synthesize it with the Audio PLL and then configure the I/O mux to output the signal, but I can't find...