New Model #9958: Retevis RT40B - CHIRP

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New Model #9958

closed

Retevis RT40B

Added by tyler two over 2 years ago. Updated about 2 years ago.

Status:

Closed

Priority:

Normal

Assignee:

Jim Unroe

Category:

Target version:

chirp-legacy

Start date:

07/27/2022

Due date:

% Done:

100%

Estimated time:

Equipment Loan/Gift Offered:

Yes

I read the instructions above:

Description

I have a 10 pack of RT40B FRS radios. I'm waiting for a programming cable - it uses a TRRS jack into the phone. I will step through some of the existing Retevis radio, including the RT22 FRS.

I don't know if it is a clone of some other radio.

Happy to ship one domestically in the U.S. to support the effort!

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native-app.txt (4.7 KB) native-app.txt	Retevis programming app USB serial output	tyler two, 08/02/2022 04:48 AM
chirp.txt (1.11 KB) chirp.txt	Chirp app USB serial output	tyler two, 08/02/2022 04:48 AM
Retevis - RT40B.pcapng (100 KB) Retevis - RT40B.pcapng	Retevis programming app wireshark dump of usbmon	tyler two, 08/02/2022 04:48 AM
Retevis_RT40B.img (517 Bytes) Retevis_RT40B.img	CHIRP Radio Images (*.ing) file from RT40B	Jim Unroe, 10/08/2022 07:33 PM

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Updated by tyler two over 2 years ago

BTW I would just gift the radio, not loan it. Why send back a cheap radio? Ha

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Updated by tyler two over 2 years ago

I was unable to get it to work with the existing Retevis presets for similar-seeming radios. I'm willing to ship a radio out to someone or to step through some more basic attempts at things - Would running the official software and somehow sniffing the USB TTY traffic help anyone?

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Updated by Jim Unroe over 2 years ago

Status changed from New to Feedback

It appears to be a model that may have some similarities with a pair of models that are supported by the retevis_rt21.py driver. I could take a look at it but I make no promise as to when a working driver can be made available or if a working driver can be provided at all.

Jim KC9HI

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Updated by tyler two over 2 years ago

File native-app.txt native-app.txt added
File chirp.txt chirp.txt added
File Retevis - RT40B.pcapng Retevis - RT40B.pcapng added

I am not a programmer and I certainly don't know much about serial I/O, but I used the info you provided and took a stab at adding a device config section....

The "magic" that the Retevis programmer outputs seems to be:
_magic = "PHOGRH" + "\x5c"

but when Chirp does the subsequent serial.read(1) it is getting back "P", and if it reads more characters (because of course I did read(100))it receives PHOGRH. It looks like this radio has remote echo? I noticed if I open a serial terminal to the radio and type, I see my characters on the screen, but it stops when I turn the radio off.

Looking at the structure of this driver, I'd say that puts this into a totally different class - it doesn't look like this echo behavior is handled by the simple per-device configs.

See attached dump of /sys/kernel/debug/usb/usbmon/3u output and a wireshark capture.

I totally understand the limitations of free software and I don't have any expectation of entitlement to your time. But let me know if I can do anything to assist.

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Updated by Jim Unroe over 2 years ago

I agree with your assessment regarding the "magic". Obviously, without a radio I cannot tell that the radio echos back any characters. There are at least 2 other Retevis models that I have done that have an echo behavior so this shouldn't be a problem. But this is as far as I can get without physical access to a RT40B. Sorry.

Jim KC9HI

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