@magpern:
It should never be hot. The thermal fuse should not be hot. Something is wrong with your module.

About range:
With module mounted inside wall (in in-wall can, below wall switch) it works fine about 10 meters from gateway.
Currently I have 5 modules working well for 6 months.
The only one problem I have is with poor quality Hongfa mini relays - some of these sometimes get sticky contacts and I need to remove wall switch and knock into relay. I changed relay to NPA-AS5 and problem gone.

I do not know how to advice you.
I suspect that there is some problem with your module - first try check why it is hot?
Or you live in very noise environment.

@magpern

No, a have no problems with sketch.
It looks like some problems with radio communication.

Diodes are only for protection transistor from reverse voltage spikes. Diodes never should be even warm. Something is wrong. You can test this without diodes.

47uF for radio is C6, you do not need to add next one.

@rolandow
There are a lot of manuals on the internet.
For example:
https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard
https://www.circuito.io/blog/atmega328p-bootloader/
https://www.instructables.com/id/Burning-the-Bootloader-on-ATMega328-using-Arduino-/
https://www.instructables.com/id/How-to-Burn-the-Arduino-BootLoader-on-to-a-AtMega3/

@magpern
About USBasp:
It is only warning, USBasp clones are working well.
But they have very old firmware, so upgrade is recommended.

About uploads:
You need to do manual reset to upload sketch.

@magpern

1. About "cannot set SCK period":
   It is common problem. You are probably using Chinese USBAsp clone.
   To remove this warning you need to update firmware in your programmer.
   Here is article how to do this. http://www.kondzio.info/elektronika/152-aktualizacja-programatora-usb-asp.html
   The article is in polish, but i hope with google translator you will be able to undestand.

2. Diode any diode 0805/SOD-80
   You can use 0805, just use little bit more tin for soldering. But you are right - SOD-80 is preffered.

3. The radio
   I know about it, but it is really no more space on PCB for do this.
   And I think make PCB bigger to add free space is not good idea.

Best regards,

@андрей-лезьёв Yes, You are right. I fixed the mistake in the description.
Valid values are: low_fuses=0xE2 high_fuses=0xD2 extended_fuses=0x06

Obviously you can skip one relay.
If you skip relay REL2 you can also skip D2,T2,R3,R4.
If you skip relay REL1 you can skip D1,T1,R1,R2

@rolandow
DRL files contains information about drilling holes in PCB.
There can be 2 types of holes at PCB:

• Plated Through Hole is a hole that has been plated and connects the top layer of the board with the bottom layer. This is in file -PTH.DRL
• Non Plated Through Hole is just hole. This is in file -NPTH.DRL

In this project ALL holes are PTH type, so file -NPTH is just empty.

I never ordered PCB in China, but i'm pretty sure that you can simply upload the same ZIP file with all Gerber files that you downloaded from openhardware.io and they will accept it. There are no need for renaming files.