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espressif / ESP8266_RTOS_SDK

Latest ESP8266 SDK based on FreeRTOS, esp-idf style.
http://bbs.espressif.com
Apache License 2.0
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SDK 2.0 SPI Master issue #231

Closed berkutta closed 5 years ago

berkutta commented 6 years ago

I'm using the newest 2.0 SDK and facing issues with the SPI Master example from https://github.com/espressif/esp8266-rtos-sample-code/blob/master/02Peripheral/HSPI_Master/user/user_main.c

Cyan/Blue is the CLK Line (GPIO14). The signal is very unstable and noisy. My Slave SPI Device (SSD1331 Display) can't handle a such noisy clock signal. Is there a solution for that?

(FYI: I don't face any of those issues with the ESP32)

ds1z_quickprint3

xiongyumail commented 6 years ago

Hi @berkutta Maybe you need an external pull-up resistor?

berkutta commented 6 years ago

Hi @xiongyumail Thanks for answering, is there an example schematic on how to use and where to put pull-up resistors on the SPI interface of the ESP8266?

berkutta commented 6 years ago

I have now tried with a 10k Pullup Resistor on HSPI CLK but it's still nearly unusuable.

berkutta commented 5 years ago

Looks like it got fixed with the new SPI driver. Thank you Espressif!

ds1z_quickprint1

xiongyumail commented 5 years ago

Thank you! I think it might be related to this option. CLEAR_PERI_REG_MASK(PERIPHS_IO_MUX_CONF_U, SPI1_CLK_EQU_SYS_CLK);