Search found 6 matches

by janlksrckts
Tue Sep 05, 2023 12:22 pm
Forum: Hardware
Topic: Jitter on 'one shot' RMT output
Replies: 2
Views: 3379

Re: Jitter on RMT output

Thanks for your reply. I found that using dedicated interrupt IO indeed makes the fixed part of the delay somewhat shorter, but the 1 us-wide 'jitter' remained the same. I also found that the 'jitter range' was equal to the resolution: rmt_config_t.clk_div = 80; // -> 1 us resolution -> 1 us 'jitter...
by janlksrckts
Sun Sep 03, 2023 10:04 am
Forum: Hardware
Topic: Jitter on 'one shot' RMT output
Replies: 2
Views: 3379

Jitter on 'one shot' RMT output

I implemented a programmable 'one-shot circuit' using RMT; a rising edge on an input GPIO pin starts a programmable delay (range from 5 us to at least 30 ms), after which an output GPIO is set high for a programmable duration (similar range). The only problem is a 1 us – wide 'jitter' on the produce...
by janlksrckts
Mon Apr 17, 2023 1:24 pm
Forum: ESP-IDF
Topic: where is the "Preprocessor Include Paths" in my eclipse IDE ?
Replies: 9
Views: 9563

Re: where is the "Preprocessor Include Paths" in my eclipse IDE ?

I also have this very same problem; no "Preprocessor Include Paths" property page. Why is this still an issue 5 years after mkseven32 posted this question? I installed and tried the Windows installers for Espressif-IDE 2.8.1, Espressif-IDE 2.9.1 and the online installer "esp-idf-tools-setup-online-2...
by janlksrckts
Fri Feb 24, 2023 3:14 pm
Forum: Documentation
Topic: ESP32 instruction set or assembly (ASM) programming docs?
Replies: 19
Views: 66166

Re: ESP32 instruction set or assembly (ASM) programming docs?

Hi ESP-Sprite, I see this thread is pretty old now, but still, you wrote: just to set expectations: don't assume you'll get an 120MHz GPIO waveform when you re-write that in assembly. On the ESP32, GPIO is routed via the APB bus and it will take the hardware multiple APB cycles to set/clear a GPIO b...
by janlksrckts
Wed Feb 22, 2023 4:53 pm
Forum: Hardware
Topic: SPI cannot deliver 800 ksps to external DAC
Replies: 1
Views: 1642

SPI cannot deliver 800 ksps to external DAC

I need the ESP32 to provide data over SPI to a 12-bit DAC (AD5452) at a rate of at least 800 ksps, this equals an update every 1.25 us. The thing with DACs however (at least the AD5452 and the MCP48XX family) is that they require the CS to briefly (30 ns) go high after every 16 bit sent. This acts a...
by janlksrckts
Thu Feb 02, 2023 9:05 am
Forum: Hardware
Topic: How to to drive an SPI DAC with DMA?
Replies: 1
Views: 1858

Re: How to to drive an SPI DAC with DMA?

Hi AutogolazzoJr
Did you ever figure out how to use DMA to MCP4922 SPI DAC and pulsing the CS of the DAC every 2 bytes?
I'm having the same issue now with an MCP4823 which is from the same DAC family. Thanks.