The cheaper "127x module":

https://www.ebay.com/itm/362762899146

and the "RA-02" model including .10 pitch breakout board:

https://www.ebay.com/itm/224085233235

I have found that the RA-02 device performs *much* better than the plain 127x module.  I get about 6x the distance (with the RA-02, well over 800 ft in my situation, from inside my house, through trees and other obstacles; only 150 ft with the cheaper module.)  I am using this antenna with IPEX connector with the RA-02:

DollaTek 433MHz Wireless 3dBi IPEX WiFi Spring Antenna for Ra-02 Module Lora OLED Board - 5pcs

Both modules use the 127x chip; perhaps the shielding on the RA-02 is a factor.  The RA-02 with the .10 pitch breakout board is also much more convenient for breadboarding as well final PCB build.

kind regards,

LouisR

There was a whole thread some time ago in which PID was a topic.
https://forum.dronebotworkshop.com/user-robot-projects/henry-ix-a-fully-autonomous-robot-platform/

  I retired from from a paper mill in 2014 after 28 years.. but i was in industrial instrumentation for over 40 years..tuned several thousand PID loops over that time, and I have a very good understanding of how it works, and how to implement it. Writing the software is the challenge.. I'm just now learning C++, so I have a ways to go in making it work on my Arduino Uno..The robot is working in the various modes it was constructed to to from the kit I bought..It has follow the light, object avoidance( utilizing IR and ultrasonic sensors), RC control via an Ir controller, and can be operated through an app on my smart phone.. I'm in no hurry, Since I'm retired, everyday is a Saturday...lol

Now, on to my project working on a PID control for my robot tank for speed control and object avoidance. It will be necessary for the the robot to be able to not only "see" what is ahead, but to decelerate and take action to avoid the object without stopping, then when clear of the object, accelerate  back to normal speed.

The challenge is writing a PID control algorithm.. so far, so good, just need more testing and adjusting proportional, integral, and derivative parameters to act fast enough to make corrective changes on the fly..

This will keep me busy for a looong while...heheh

good luck on your project, and thanks for the heads up on the SX127X board...

kind regards,

LouisR

Sorry for such a long wait in replying.

I stopped pursuing my attempts to get the RYLR890 working, as I found using SX127x breakout modules much easier to use. (The RYLR890 uses the SX127x, inside a layer of additional processing.):

eg: https://www.ebay.com/itm/362762899146

("RA-01" module:) https://www.ebay.com/itm/183432900897

("RA-02" module - requires external antenna:) https://usa.banggood.com/433MHZ-SX1278-LoRa-Module-433M-10KM-Ra-02-Wireless-Spread-Spectrum-Transmission-Board-2_4G-IPX-Antenna-for-Smart-Home-p-1939044.html?cur_warehouse=CN

Note that the first and the RA-01 modules have a < .1in pitch, so you have to fashion your own header to fit into a .1in form (proto board, etc.)  The RA-02 is .1in pitch.

You do not get AT commands using only the SX127x breakout module, but as the commands are all strings, it is a simple matter to encode the strings with your own identifiers if you want to segregate "channels" etc.

It is nicer because you don't really need the extra processing layer the RYLR890 is providing, and programming is simpler (IMO.)

CAVEAT: There are several tutorials on how to set these up using Arduino, however, they appear to be copied from the same tut.  I say this because in all of them, they show the Arduino (a 5v device) IO pins connected directly to the SX127x (a 3.3v device) IO pins with no level shifting.  They state that you only have to observe powering the SX127x with 3.3v, and and make no mention of level shifting as though it is not necessary.  THIS IS NOT TRUE.  My experience was it will not work, and in hindsight, I am lucky I didn't damage the SX127x.

If you follow the tuts, just be sure to use a level shifter.  Make sure you check the speeds and use one fast enough for the Arduino clock speeds (16 MHZ.)  I used a TXB0108 (20 MHZ) which fit the bill and it is working fine.  Or use a 3.3v Arduino (Note, I believe the 3.3v Arduinos are only 8 MHZ.)

(You may get away with using resistor voltage dividers for level shifters also, which could reduce your component footprint, but note that will affect speed.  I tried it and it seemed to work, but I just played it safe and used the TXB0108. YMMV.)

Here is one of the tuts.  It should give everything you need to know regarding wiring (just use a level shifter) and the code:

https://how2electronics.com/interfacing-sx1278-lora-module-with-arduino/

There are several on YouTube as well, just search "SX1278 arduino".

You guy have a great weekend too!

regards,

LouisR

The song said Never on a Sunday :)