Search found 54 matches

by KanyeKanye
Thu Mar 23, 2017 8:33 pm
Forum: General Discussion
Topic: WROOM antenna radiation pattern
Replies: 2
Views: 2486

WROOM antenna radiation pattern

Does anyone got WROOM antenna radiation pattern graph?
Which way does it radiate most?
by KanyeKanye
Mon Mar 20, 2017 8:09 pm
Forum: General Discussion
Topic: Powering my esp32 projects
Replies: 6
Views: 13795

Re: Powering my esp32 projects

Maybe a joule thief :)
You can use your 0.2Ah battery. Value 0.2A (and even more) I wrote before is true when everything is on. Just remember about it writing a code, switch into powersave mode as often as it is possible, use pullups 10k and do not use a wifi too often
by KanyeKanye
Sun Mar 19, 2017 11:07 am
Forum: General Discussion
Topic: I2C: protection against connection (lines) problems
Replies: 9
Views: 5478

I2C: protection against connection (lines) problems

Each time, when I2C's lines SCL or SDL stops connect (eg. I am unplugging it), i2c_master_cmd_begin returns ESP_FAIL or ESP_ERR_TIMEOUT . If ESP_ERR_TIMEOUT is returned, I2C wont work anymore - after replugging disconnected pins, result is still ESP_ERR_TIMEOUT . How to protect it to recover after d...
by KanyeKanye
Sun Mar 19, 2017 9:25 am
Forum: General Discussion
Topic: Powering my esp32 projects
Replies: 6
Views: 13795

Re: Powering my esp32 projects

5V power supply would damage esp.
Esp if you're not too frugal (wifi on, low value resistors for pullups) needs about 0.2A and your battery will die in 1 hour.
by KanyeKanye
Sat Mar 18, 2017 10:59 pm
Forum: General Discussion
Topic: Hardware timer
Replies: 1
Views: 1814

Hardware timer

CPU freq is 240MHz. Timer configuration is like the one below. I check if timer_val (from timer_get_counter_value) is larger than 36621 (36621 * 0xffff = 2 399 957 235). I believed it was 10seconds, but it seems to take more than 31 secs; why? Are some timers used by WiFi or interface's (I2C, SPI, S...
by KanyeKanye
Wed Mar 15, 2017 8:02 pm
Forum: General Discussion
Topic: RTC hold capacitor
Replies: 1
Views: 1335

RTC hold capacitor

I would use WROOM module, so VDD3P3_RTC is not available.
How can I hold RTC when main power is down and do not drain its energy too fast - how to programmatically switch off everything but RTC, what current is needed than?
by KanyeKanye
Wed Mar 15, 2017 7:44 pm
Forum: General Discussion
Topic: Where is fourth SPI
Replies: 5
Views: 3454

Where is fourth SPI

I use esp-wroom-32 module (so flash is build in). I need sd card interface and two more independent SPI interfaces.
I see SPICLK - SCK/CLK, HSPICLK - IO14, VSPICLK - IO18. Where is last, fourth one clk pin?
What about its speed? Which is best for TFT Display connection?
by KanyeKanye
Thu Feb 23, 2017 10:58 pm
Forum: General Discussion
Topic: SDCard card detect and write protect pins
Replies: 6
Views: 3750

SDCard card detect and write protect pins

How to use gpio_cd and gpio_wp?
I am unable to find it anywhere else but inside sdmmc_host_init_slot.
by KanyeKanye
Sun Dec 18, 2016 9:59 pm
Forum: General Discussion
Topic: Allocating more memory result in bulk errors
Replies: 2
Views: 2747

Allocating more memory result in bulk errors

Working with WiFi, whenever I alloc any buffer larger than ~64bytes, my code crashes, but whats important I am unable to detect any accurate place where it does. Like there would be no more memory and when some background things for WiFi receive some packets, alloc space for them, the code stops: ch...