Search found 10 matches

by BuGless
Thu Oct 01, 2015 3:58 pm
Forum: ESP8266 HDK
Topic: Internal pull-up of CHIP_EN
Replies: 3
Views: 2349

Re: Internal pull-up of CHIP_EN

Did you try to measure the internal nRESET pull-up?
(I.e. attach a capacitor, and then measure the time it takes to charge it?)
by BuGless
Thu Oct 01, 2015 3:48 pm
Forum: ESP8266 HDK
Topic: PWM registers?
Replies: 4
Views: 2335

Re: PWM registers?

Indeed. Seems you are right. That will mean I need to design in an extra MCU to control the PWMs. Thanks for the input.
by BuGless
Thu Oct 01, 2015 8:27 am
Forum: ESP8266 HDK
Topic: PWM registers?
Replies: 4
Views: 2335

Re: PWM registers?

Interesting. This begs the question though, what is the resolution of the PWM pulses, and how accurate does it maintain fixed phase relationships between different PWM channels? How well can it guarantee that the width of the pulses stays unaltered? I'm trying to reach 25ns resolution with respect t...
by BuGless
Wed Sep 23, 2015 6:19 pm
Forum: ESP8266 HDK
Topic: PWM registers?
Replies: 4
Views: 2335

PWM registers?

I'm in need of actually only one PWM (one frequency), but with five or possibly even six outputs with six different duty cycles. Is there documentation regarding the PWM configuration registers? Sample code? Any suggestions on how I create one or two extra PWM outputs with a different duty cycle (bu...
by BuGless
Thu Sep 17, 2015 9:01 pm
Forum: ESP8266 HDK
Topic: Internal pull-up of CHIP_EN
Replies: 3
Views: 2349

Re: Internal pull-up of CHIP_EN

When reading between the lines, I'm guessing that the pin indeed *has* an internal pull-up, however... These internal pull-ups (on all of those pins where they are) probably are reasonably weak (I'm guessing >50kohm). So that implies that they work perfectly fine if pins are non-critical and left da...
by BuGless
Wed Sep 09, 2015 3:50 am
Forum: ESP8266 HDK
Topic: Series resistor of 200 Ohm on SD_CLK
Replies: 1
Views: 1334

Series resistor of 200 Ohm on SD_CLK

How is that value of 200 Ohm determined?
What if I'd use 300 Ohm instead; would that work better, worse, equally well? Why not?
by BuGless
Wed Sep 09, 2015 2:52 am
Forum: ESP8266 HDK
Topic: Pull up resistors
Replies: 2
Views: 5254

Pull up resistors

In the pin specs I see wpu and wpd. I presume that means weak-pull-up and weak-pull-down respectively.
What are the specs on those wpu and wpd resistors?
by BuGless
Wed Sep 09, 2015 2:50 am
Forum: ESP8266 HDK
Topic: Decoupling capacitors
Replies: 1
Views: 2731

Decoupling capacitors

I see different recommendations for decoupling capacitors depending on which application/design guide I read. The following questions come to mind: a. The VDDPST explicitly does not need a decoupling capacitor. Does that mean that it merely pulls a completely flat DC current? I'd normally say that a...
by BuGless
Wed Sep 09, 2015 2:26 am
Forum: ESP8266 HDK
Topic: Crystal frequency 24MHz supported?
Replies: 1
Views: 1195

Crystal frequency 24MHz supported?

In some of the latest specs I see that the supported frequency range for the crystal is 26MHz to 52MHz. In other documents (and older documents) I see that it is 24MHz or 26MHz or 40MHz. Does that now mean that 24MHz is still supported? Also, does it matter which frequency one uses between 26Mhz and...
by BuGless
Wed Sep 09, 2015 2:04 am
Forum: ESP8266 HDK
Topic: 5V tolerant inputs?
Replies: 1
Views: 1666

5V tolerant inputs?

In the specs I see that the digital inputs are protected by 5.8V clamping diodes.
Does that mean that all digital inputs are 5V tolerant?
I.e. if I apply 5V to a digital input, will it register as a logic one, and will there be no damage to the ESP8266?

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