Search found 7 matches

by blark
Thu Jan 30, 2020 2:38 pm
Forum: ESP32 boards
Topic: Hardware SPI ~0.85ms delay before sending data
Replies: 3
Views: 290

Re: Hardware SPI ~0.85ms delay before sending data

I'm still kind of hung up on this, anyone know if it's possible to use Viper to directly access the HW SPI peripheral? I cranked the ESP32 frequency up to 240MHz and it's still taking a long time between SPI messages. In contrast the STM32 running at 84Mhz that I am sending 1000 bytes of data to pro...
by blark
Wed Jan 15, 2020 4:21 pm
Forum: ESP32 boards
Topic: Hardware SPI ~0.85ms delay before sending data
Replies: 3
Views: 290

Re: Hardware SPI ~0.85ms delay before sending data

Not much improvement at all from caching bytes. I found another thread on this that states there is a lot of data checks and SPI setup going on in the background. It seems like something that could possibly be optimized. I guess I will use large transfers (of about 1KB at a time) so I don't experien...
by blark
Mon Jan 13, 2020 7:30 pm
Forum: ESP32 boards
Topic: Hardware SPI ~0.85ms delay before sending data
Replies: 3
Views: 290

Hardware SPI ~0.85ms delay before sending data

I have a question about delays that I'm experiencing with hardware SPI. I have the following code which sends 16 bytes of data: vspi = SPI(2, 1000000, polarity=0, phase=0, bits=16, firstbit=0, sck=Pin(18), mosi=Pin(23), miso=Pin(19)) test = bytearray(16) ss.off() vspi.write_readinto((0xff).to_bytes(...
by blark
Fri Jan 10, 2020 5:36 pm
Forum: ESP32 boards
Topic: Hardware SPI instability issues (vspi, hspi) - SS oscillating
Replies: 5
Views: 168

Re: Hardware SPI instability issues (vspi, hspi) - SS oscillating

Ahh, yes I was using 1x and I only used the spring clip on the SS line because I don't have 6 hands :lol: I'll play around with 10x next as well, thanks very much! Edit: yes, the scope goes down to 50MHz max when I use two channels. I have the DS1054Z with the 100MHz hack Edit 2: 100Mhz and 10x prob...
by blark
Fri Jan 10, 2020 5:04 pm
Forum: ESP32 boards
Topic: Hardware SPI instability issues (vspi, hspi) - SS oscillating
Replies: 5
Views: 168

Re: Hardware SPI instability issues (vspi, hspi) - SS oscillating

Wow! What a massive difference that spring clip makes (again yellow = SCK, cyan = SS) https://i.imgur.com/TotX2zQ.png Again, thanks very much for the help on this. And for your patience with my n00b scope skills ;) Hopefully someone else with a similar issue might stumble across this and save a bunc...
by blark
Fri Jan 10, 2020 4:46 pm
Forum: ESP32 boards
Topic: Hardware SPI instability issues (vspi, hspi) - SS oscillating
Replies: 5
Views: 168

Re: Hardware SPI instability issues (vspi, hspi) - SS oscillating

Awesome. It sounds like this is just a bad GND connection. I'm using the stock Rigol DS1054 probes with the Alligator style clips. I will do some research into what I can do to improve the accuracy of my readings. Thanks for the quick and thorough feedback!
by blark
Fri Jan 10, 2020 3:34 pm
Forum: ESP32 boards
Topic: Hardware SPI instability issues (vspi, hspi) - SS oscillating
Replies: 5
Views: 168

Hardware SPI instability issues (vspi, hspi) - SS oscillating

I am having issues with the hardware SPI on several boards running MicroPython. I've tried nightlies, 1.12 and 1.11 to see if this might be an issue related to a single firmware. The behavior is the same across all hardware and firmware versions. I've tested ESP-WROOM-32 modules from both Adafruit (...