Works with various ESP-IDF versions

README.md

@@ -2,7 +2,7 @@
 
 # TL;DR
 
-This port of FastLED 3.3 runs under the 4.0 ESP-IDF development environment. Enjoy.
+This port of FastLED 3.3 runs under the 4.x ESP-IDF development environment. Enjoy.
 
 Pull requests welcome.
 
@@ -41,11 +41,27 @@ or might not be correct for your ESP32. I've checked in a version that runs at 2
 runs both cores, uses 40Mhz 4MB DIO Flash, auto-selects the frequency of the clock, and
 only runs on Rev1 hardware, and has turned off things like memory poisoning.
 
+Because I'm trying to support different versions of esp-idf, and the sdkconfig files seem
+contradictory, the one in this repo matches "current" master, with a 4.0, 4.1, and 4.2 version.
+If you'd like to test my starting point, copy the correct one over to sdkconfig and
+give it a try.
+
 I've read scary stuff about Rev0 and GPIO. You have to insert a number of NOP statements
 between bangs of the pins. If you're using that version, you might want to look carefully
 into the issue.
 
-# Use of ESP32 hardware for 3 wire LEDs
+# a note about level shifting
+
+I've now read a lot of reddit posts about people saying "but I hook LEDs up to an Arudino and it works,
+but the ESP32 is flakey". Why yes. That's because ESP32 pins are 3.3v, Arduino pins are 5v, and LED signal
+levels are 5v. Either you get lucky with the LEDs you have, or you go find out about level shifting.
+
+Adafruit's page on level shifting is perfectly good, although you don't need a breakout board,
+and using a 4-pin package isn't so cool as an 8 pin package, since an ESP32 can drive
+8 channels. That's SN74HCT245N , and they're to be had from Digikey at $0.60. Read the datasheet
+carefully and get the direction and the enable pins right - they can't float.
+
+# Use of ESP32 hardware (RMT) for 3 wire LEDs
 
 The ESP32 has an interesting module, called RMT. It's a module that's
 meant to make arbitrary waveforms on pins, without having to bang each pin at
@@ -59,12 +75,16 @@ channels.
 
 The FastLED ESP32 RMT use has two modes: one which uses the "driver", and
 one which doesn't, and claims to be more efficient due to when it's converting
-between LED RGB and not. I have not tested whether using the ESP driver
-works.
+between LED RGB and not. 
 
 Whether you can use the "direct" mode or not depends on whether you have other
 users of the RMT driver within ESP-IDF. 
 
+It also depends on the version of ESP-IDF you're using. I've found that the "direct"
+driver works perfectly well in ESP-IDF 4.0, but with higher versions, there
+are incompatibilities. Since I haven't found solutions yet, the built-in driver
+is used with ESP-IDF v 4.1 and above.
+
 Essentially, if you have the Driver turned on, you shouldn't use the direct mode,
 and if you want to use the direct mode, you should turn off the driver.
 
@@ -109,7 +129,7 @@ have threads of control or message queues or anything like that.
 
 # A bit about esp-idf
 
-ESP-IDF, in its new 4.0 incarnation, has moved entirely to a cmake infrastructure.
+ESP-IDF, in its new 4.x incarnation, has moved entirely to a cmake infrastructure.
 It creates a couple of key files at every level: `CMakeLists.txt` , `Kconfig`. 
 
 The `CMakeLists.txt` is where elements like which directories have source and includes live.
@@ -129,6 +149,34 @@ There's no way to remove components you're not using. Don't want to compile in H
 The menuconfig system allows you to not run it, but you can't not compile it without
 going in and doing surgery.
 
+# ESP-IDF versions
+
+First of all, if you're changing versions, you have to be quite careful. The only foolproof method
+I've found is a brand new clone, a new install.sh, manually removing the project's build directory,
+and using the defult sdkconfig with a menuconfig, setting the parameters you need within this version.
+
+Within menuconfig, I tend to use the following settings. Minimum required silicon rev to 1, because there 
+are speed workarounds at Rev0 that get compiled in. I change the compiler options to -O2 instead of -Os or -Og.
+Default flash size to 4M, because all the devices I have are 4G.
+
+Second of all, there be some dragons in the different versions.
+
+The FastLed RMT code runs in two different modes - it either uses an onboard driver, or it uses the ESP-IDF RMT driver.
+I've found that if you use the driver that was originally written for FastLED, it works great with ESP-IDF 4.0,
+but crashes horribly in 4.2 and master. These are interesting branches because the new S2 version of the ESP32
+chip requires those branches.
+
+It's quite possible that more and more changes will creep in, or that someone will find the flaw that's causing 4.2
+to crash.
+
+# A short plug for Microsoft's WSL
+
+Although ESP-IDF v4.x has apparently made great strides in working with VS and Platform.io, they still suggest
+you use cmake in windows. This avoids the elephant which is WSL - Windows Service for Linux. I use that
+exclusively for this project, and all of the instructions on how to install and use ESP-IDF for Linux work great,
+including flashing devices over USB. Serial devices are mounted as "/dev/ttySX", where X is the COMM number in the
+device. Really works nicely.
+
 # History 
 
 ## The other FastLED-idf
@@ -155,6 +203,14 @@ be everyone's guest!
 I did reach out to Espressif. I think they should include or have a FastLED port.
 In their forums, they said they don't intend to do anything like that.
 
+## SamGuyer's fork
+
+According to a reddit post, someone named Sam Guyer fixed the issues with FastLED by using some async
+mechanisms. This is still an arduino port, but maybe it's best to port this over next.
+
+https://github.com/samguyer/FastLED
+
+
 # Updating
 
 This package basically depends on three packages: two that you pull in,
@@ -206,7 +262,7 @@ However, really being multi-core would mean having a locking semantic around the
 array, or double buffering. FastLED doesn't seem to really think that way,
 rightfully so.
 
-# Liscening
+# Licensing
 
 FastLED is MIT license.