Search found 14 matches
- Wed Sep 06, 2023 5:54 am
- Forum: 硬件问题讨论
- Topic: ESP32-S2FN4R2 内置Flash和PSRAM时， VDD_SPI怎么接？
- Replies: 1
- Views: 18884
ESP32-S2FN4R2 内置Flash和PSRAM时， VDD_SPI怎么接？
看文档， 此时应该使用 主电源输入配合芯片内部的一个 Rspi， 那么 VDD_SPI 只要接一个电容到地就可以了吗？ RSPI的作用什么？
- Mon Jun 05, 2023 2:44 pm
- Forum: 硬件问题讨论
- Topic: 想确认一下 esp32 s2 支持 gc032a 摄像头， 对吗？
- Replies: 1
- Views: 2155
想确认一下 esp32 s2 支持 gc032a 摄像头， 对吗？
看规格应该可以， 但是想最终确认一下
- Wed May 10, 2017 9:21 am
- Forum: General Discussion
- Topic: can I use esp32 as a bluetooth TAG, and limit esp32 tx range in 0.5m?
- Replies: 0
- Views: 3285
can I use esp32 as a bluetooth TAG, and limit esp32 tx range in 0.5m?
这个可以被实现吗？
Could it be implemented?
Could it be implemented?
- Fri Apr 07, 2017 3:36 am
- Forum: General Discussion
- Topic: how to use esp32 input capture and motor pwm function?
- Replies: 15
- Views: 36634
- Thu Mar 23, 2017 3:58 am
- Forum: General Discussion
- Topic: only three slave can be attached in SPI ?
- Replies: 8
- Views: 17496
Re: only three slave can be attached in SPI ?
Ooops.... I can set spics_io_num = -1, but when I call spi_bus_add_device > 3 times, driver still said E (199) spi_master: spi_bus_add_device(326): no free cs pins for host .... If you wan to use more than 3 devices, you have to modify spi_bus_add_device() function, something like this: #define NO_...
- Wed Mar 22, 2017 6:53 am
- Forum: General Discussion
- Topic: only three slave can be attached in SPI ?
- Replies: 8
- Views: 17496
Re: only three slave can be attached in SPI ?
maybe i call spi_bus_add_device once, with a dummy CS pin number, and select CS via GPIO manually? why the API has this limit? You can set the divice configuration not to use CS ( spics_io_num = -1 ) in spi_device_interface_config_t structure int spics_io_num; ///< CS GPIO pin for this device, or -...
- Tue Mar 21, 2017 9:01 am
- Forum: General Discussion
- Topic: only three slave can be attached in SPI ?
- Replies: 8
- Views: 17496
Re: only three slave can be attached in SPI ?
yeah, i did this and use .pre_cb and .post_cb to tgl CS pin
thank you!
thank you!
- Tue Mar 21, 2017 3:08 am
- Forum: General Discussion
- Topic: only three slave can be attached in SPI ?
- Replies: 8
- Views: 17496
Re: only three slave can be attached in SPI ?
maybe i call spi_bus_add_device once, with a dummy CS pin number, and select CS via GPIO manually?
why the API has this limit?
why the API has this limit?
- Tue Mar 21, 2017 3:01 am
- Forum: General Discussion
- Topic: only three slave can be attached in SPI ?
- Replies: 8
- Views: 17496
only three slave can be attached in SPI ?
i have layouted a PCB, esp32 connect 5 spi slave, share same CLK/ MISO/ MOSI and 5 independent nCS to every device. but when I use spi_bus_add_device() 5 times, it said: E (199) spi_master: spi_bus_add_device(326): no free cs pins for host E (199) spi_master: spi_bus_add_device(326): no free cs pins...
- Fri Jan 13, 2017 7:30 am
- Forum: Hardware
- Topic: External Interrupt Latency
- Replies: 17
- Views: 36621
Re: External Interrupt Latency
I have done a measurement and delay from external trigger to application-provided ISR handler is around 2us (at 240MHz clock), which is around 500 cycles. yes, real interrupt delay is about 1.7~1.8uS, it seems too long for a 240Mhz processor, I measure the delay on a 32Mhz 8bit mcu, delay is ~700nS...