ESP8266 Community Forum

- Mon Jun 18, 2018 7:40 am #76508 "The mathematical description of a quantum system typically takes the form of a "wavefunction," generally represented in equations by the Greek letter psi: Ψ. There's a lot of debate about what, exactly, this wavefunction represents, breaking down into two main camps: those who think of the wavefunction as a real physical thing (the jargon term for these is "ontic" theories, "
True but there is a discrete formulation due to Dirac.It is absolutely equivalent if you entertain the notion of wave collapse upon measurement. The Issue with psi is that it is a continuous whereas quantum states take on specific values as transitions between states aren't smooth. All waves involve the square root of minus one so does probability. If the wave is considered an emerging probability like dice thrown in the air contain the probability of all possible results but upon landing select a specific one with a frequency commensurate with the probability it is easier to see the connection between Dirac and psi. Anyway as much as we are intrigued by coding it is good to remember er it is the electrons that do all the work. A healthy respect for electrons very often makes for better coding.

- Mon Jun 18, 2018 8:15 am #76511

Sorry, but the description of QIO DIO etc means a lot to the engineer that designed the HW & SW. But I was raised with the phrase "It's all Greek to me.".

Do you know about interfacing a SPI device to an Arduino? For example a SD memory card. The Arduino/CPU/ESP8266 has a serial output pin, a serial input pin, a clock pin, and an enable pin to select the memory. All the information is transferred through one Data line to the SD card, and one Data line back to the CPU.

That was the basic serial flash chip. Because all the communications is through one line (per direction) it is slow. What if you could use two data lines? Or four? Then the transfers would take less time.

That is what this is about. Chips that have an enhanced SPI interface where data can be transferred through more pins rather than the original SPI configuration.

And I will translate the Greek for you.

I/O means Input/Output
Dual means two.
Quad means four.
Output means Output

This table from the excellent link provided.

Code: Select allOption   Mode Name   Pins Used                            Speed (ESP8266 & ESP32)
qio    Quad I/O      4 pins used for address & data       Fastest.
qout   Quad Output   4 pins used for data.                Approx 15% slower than qio.
dio    Dual I/O      2 pins used for address & data       Approx 45% slower than qio.
dout   Dual Output   2 pins used for data.                Approx 50% slower than qio.

Last edited by rudy on Tue Jun 19, 2018 7:38 pm, edited 1 time in total.

- Tue Jun 19, 2018 2:05 am #76515

And I will translate the Greek for you.

I'm voting this topic to be stickied!

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.