8000 [Enhancement] Make Wire and SPI lib compatible between ESP32 and ESP8266 · Issue #3691 · esp8266/Arduino · GitHub
[go: up one dir, main page]
Skip to content

[Enhancement] Make Wire and SPI lib compatible between ESP32 and ESP8266 #3691

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Open
olikraus opened this issue Oct 8, 2017 · 6 comments
Open

[Enhancement] Make Wire and SPI lib compatible between ESP32 and ESP8266 #3691

olikraus opened this issue Oct 8, 2017 · 6 comments

Comments

@olikraus
Copy link
olikraus commented Oct 8, 2017 •
edited
Loading

Basic Infos

This is a feature extension request to make the ESP32 and ESP8266 library compatible with each other.
From my analysis i would suggest to modify ESP8266 library and align with ESP32 library. However other modifications are also thinkable. For more specific suggestions, see below.

Discussion reference:
olikraus/u8g2#377
olikraus/u8g2#378

Hardware

Hardware: n.a.
Core Version: head

Description

Problem description

Assigning movable pins for ESP32 and ESP8266 differs between the projects.

Settings in IDE

n.a.

Sketch

n.a.

Debug Messages

n.a.

Analysis of the Problem

SPI Lib ESP8266:
Link: https://github.com/esp8266/Arduino/blob/master/libraries/SPI/SPI.h#L56
Uses "pins" member function to assign movable pins:
pins(int8_t sck, int8_t miso, int8_t mosi, int8_t ss);
Note, that ss and mosi are required areguments

SPI Lib ESP32:
Link: https://github.com/espressif/arduino-esp32/blob/master/libraries/SPI/src/SPI.h#L55
The begin() member function accepts several (optional) arguments for
the assignment of the pin numbers:
"void begin(int8_t sck=SCK, int8_t miso=MISO, int8_t mosi=MOSI, int8_t ss=-1);"

Wire Lib ESP8266
Link: https://github.com/esp8266/Arduino/blob/master/libraries/Wire/Wire.h#L53
Has a "pins" member function which is declared as deprecated.
"pins(int sda, int scl)"
Instead use "begin(int sda, int scl);"

Wire Lib ESP32
Link: https://github.com/espressif/arduino-esp32/blob/master/libraries/Wire/src/Wire.h#L55
The ESP32 Wire lib extends the begin() member function with optional pin
arguments and also a frequency paramenter:
"void begin(int sda=-1, int scl=-1, uint32_t frequency=100000);"

Conclusion

  1. All four extensions are none-standard extensions on the Arduino Core libraries (not
    sure whether they are documented)
  2. SPI Lib extensions are completly incompatible between ESP32 and ESP8266
  3. Wire extensions partly compatible between ESP32 and ESP8266, but ESP has
    an extra frequency parameter and scl line is optional, this means you can specify "begin(X)"
    to move the sd line to pin X, which is not possible on ESP8266.
  4. The extension of "begin()" member function is used in 3 of 4 cases. So the
    approach in SPI lib of ESP8266 does not seem to fit.

Suggestions for modification

ESP8266 and ESP32 should agree on common code regarding the extension
for movable pins for SPI and Wire functionality.

From seeing the above differences my suggestion is to modify the ESP8266 project
to make it compatible to the ESP32 project:

  • SPI Lib: Introduce void begin(int8_t sck=SCK, int8_t miso=MISO, int8_t mosi=MOSI, int8_t ss=-1);
  • Wire Lib: Modify "begin(int sda, int scl);" to "void begin(int sda=-1, int scl=-1, uint32_t frequency=100000);"
@olikraus olikraus changed the title [Enhancement] Make Wire and SPI lib compatible between ESP32 and ESP8266 [Enhancment] Make Wire and SPI lib compatible between ESP32 and ESP8266 Oct 8, 2017
@olikraus olikraus changed the title [Enhancment] Make Wire and SPI lib compatible between ESP32 and ESP8266 [Enhancement] Make Wire and SPI lib compatible between ESP32 and ESP8266 Oct 8, 2017
@olikraus olikraus mentioned this issue Oct 8, 2017
Closed
@me-no-dev
Copy link
Collaborator

I agree :) We could also add Wire::pins(sda, scl) to ESP32 ;)

@devyte
Copy link
Collaborator
devyte commented Oct 10, 2017

Since we're discussing compatibility and api, do we want to consider #2677 here?

@olikraus
Copy link
Author

As a library author I fully agree that the API fuctions for SPI and Wire should be the same to avoid ifdefs.

@freeck
Copy link
freeck commented Oct 10, 2017 •
edited
Loading

Same for the file system api's for SD, FS, SDFAT libraries...

@me-no-dev
Copy link
Collaborator

FS compatibility is not that simple to do ;) ESP32 follows Arduino's SD API and SPIFFS on ESP8266 uses a different API from the rest. Changing either will bring more issues than anything.

@olikraus
Copy link
Author

I personally would be happy if at least ESP32 and ESP8266 extensions for SPI and Wire libs are compatible.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
4 participants
@olikraus @freeck @me-no-dev @devyte
0