I’m standing at my Rubicon (an ancient river, famously crossed by Julius Caesar in 49 BC). I’ve owned my Ender 3 for about two years, put a BTT SKR Mini E3 V2 in it about a year ago, and so far, have never felt a need to mess with the firmware. Until now. My kids gave me an infrared thermometer for X-mas, and I discovered that the bed temp is running 5 to 8 degrees lower than it’s set point of 65 degrees. PID Autotune is not enabled in firmware but I was able to use Gcode (in the terminal) to tune the nozzle. When I tried to do the bed I got an error, E-1 was not recognized as a valid input. My assumption is that I get the error because it’s not enabled in firmware.
So, here’s the question, is it worth the trouble (I’ve never tried to edit, compile or flash firmware, ever) for me to teach myself how to do it, and should I even mess with trying to do PID tuning on the bed in the first place? I also have an ABL device (it’s been in a drawer for about 9 months) that I’m thinking of installing, so if I’m in there messing with the configuration.h file I might as well enable that. I’m overwhelmed by the sheer number of files and options that I don’t know where to start. It’s hard to ask the right questions when you don’t know what questions to ask.
This is what I got when I entered M115 in the terminal: FIRMWARE_NAME: Marlin bugfix-2.0.x /Marlin PROTOCOL_VERSION:1.0 MACHINE_TYPE:SKR-mini-E3-V2.0
Most of what I’ve found in my web searching are ads trying to sell me what I already have, or “here’s how you do it in three easy steps” that leave people like me, who have never done this before, scratching our heads, because they assume we know what they are talking about. I want to learn how to do this, I just need a good place to start the process. If you’ve made it this far, I appreciate your patience.
Given that your firmware is based on bugfix-2.0.x, its already old 
There’s been a TON of improvements in Marlin since then.
You’ll want to use MPCTEMP to control your hotend temperatures - which is a massive jump up from PID.
The good thing is, with my site, it already had a build ready to go for your printer and mainboard:
If you don’t add the BLTouch, you can use this one:
It should be pretty much plug and play - which takes a lot out of the stress levels of making this all work. If I’m honest, this web site is designed and run purely to make things easier for people to experiment with 3D printing. If you’re not a programmer or tinkerer with software, the barriers to entry can be quite high when we’re talking advanced topics like 3D printer firmware - but it really doesn’t have to be that way. That’s what I want to achieve.
That being said, you will always notice a difference on the build plate vs what the set temperature is - because the temp sensor is under the bed - not on the build surface. Most people just add a few degrees to their bed temp if they need it.
That being said, it normally is better to have more precise monitoring and control in the firmware vs using BANG BANG - which is what your current firmware is probably doing.
First of all, thank you for your reply. As I mentioned, I’ve had my Ender 3 for about two years now, running on the SKR Mini for the last year, and as you said, “There’s been a TON of improvements”. It’s printing ok for my needs, but I wouldn’t mind having access to the features that up-to-date firmware could provide. I recently updated the firmware on my laser engraver and that was a pretty painless affair, but that didn’t require any editing of the file. For instance, if I enable BLTouch in the firmware of my Ender, do I need to have the hardware installed first or can I wire that in later? I would like to find a tutorial geared towards a first timer, like me, that can explain step-by-step which files I need and how to go about editing them and then uploading them to the printer, without bricking it! That’s very important to me…I keep telling myself…“Paul, don’t brick your printer”. Your site is a very good resource for people like me which is why I was more than happy to contribute financially. In addition to your .bin file I assume I’m going to have to edit the configuration.h file to enable the features I want, but I honestly don’t know. Can you recommend a link or site that would give me a good grounding in the art of firmware updating? Again, thank you for being here for people like me.
Firstly, its very difficult to completely brick a printer.
The SKR boards have their own bootloader - and its almost impossible to kill them via firmware upgrade.
Using the pre-built .bin file, you don’t need to edit any configuration files. Copy the file to the SD Card, rename it firmware.bin, plug it into the machine and power it up. That’s it.
If you don’t do the BLTouch first, then run the non-BLTouch firmware - you won’t need to change the firmware until you install the BLTouch and want it to work.
There are a number of YouTube videos that go through the process of physically installing the BLTouch - and there’s also an FAQ on the BLTouch on this forum that has a bit more details - but the BLTouch based firmware on this site already has the modifications needed to run out of the box.
Thank you. I’m going to try the non-BLTouch first and see how that works out. After test driving that around for awhile I’ll install my BLTouch and then flash the other .bin file. Cheers!