Main features:

• OneOfEleven mods, including AM fix
• fagci spectrum analyzer (F+5 to turn on)
• better battery percentage calculation (based on real measurement, battery calibration recommended)
• battery calibration option available available in the menu (instructions below)
• there is no FM radio nor Aircopy, not enough memory space

❗❗❗You can now calibrate the battery voltage reading in the radio menu.

To enter the calibration:

1. turn the radio on holding PTT and the first side button
2. imediately go to BATVOL option and adjust the voltage with UP/DOWN buttons
3. confirm the setting, calibration will be saved to EEPROM

The calibration option becomes unavailable if you leave the menu screen and you have to repeat from step 1.

Open reimplementation of the Quan Sheng UV-K5 v2.1.27 firmware

This repository is a merge of OneOfEleven custom firmware with fagci spectrum analizer plus my few changes.

https://github.com/OneOfEleven/uv-k5-firmware-custom
https://github.com/fagci/uv-k5-firmware-fagci-mod/tree/refactor

All is a cloned and customized version of DualTachyon's open firmware found here ..

https://github.com/DualTachyon/uv-k5-firmware .. a cool achievement !

Use this firmware at your own risk (entirely). There is absolutely no guarantee that it will work in any way shape or form on your radio(s), it may even brick your radio(s), in which case, you'd need to buy another radio. Anyway, have fun.

Radio performance

Please note that the Quansheng uv-k radios are not professional quality transceivers, their performance is strictly limited, somewhat below that of a decent transceiver. The RX front end has no track-tuned band pass filtering at all, and so are wide band/wide open to any and all signals over a wide frequency range. Using the radio in high intensity RF environments will nearly always destroy your reception, the receiver simply doesn't have a great dynamic range, though are quite sensitive (weak signal wise).

Saying that, they are nice toys for the price, fun to play with.

User customization

You can customize the firmware by enabling/disabling various compile options. You'll find the options at the top of "Makefile" ('0' = disable, '1' = enable) ..

ENABLE_SWD                    := 0       only needed if using CPU's SWD port (debugging/programming)
ENABLE_OVERLAY                := 0       cpu FLASH stuff
ENABLE_LTO                    := 0     **experimental, reduces size of compiled firmware but might break EEPROM reads - DISABLE overlay if you enable this
ENABLE_UART                   := 1       without this you can't configure radio via PC
ENABLE_AIRCOPY                := 0       easier to just enter frequency
ENABLE_FMRADIO                := 1       WBFM VHF band 2 RX
ENABLE_NOAA                   := 0       everything NOAA
ENABLE_VOICE                  := 0       want to hear voices ?
ENABLE_ALARM                  := 0       TX alarms
ENABLE_1750HZ                 := 0       side key 1750Hz TX tone
ENABLE_BIG_FREQ               := 0       big font frequencies
ENABLE_SMALL_BOLD             := 1       bold channel name/no. (when name + freq channel display mode)
ENABLE_KEEP_MEM_NAME          := 1       maintain channel name when (re)saving memory channel
ENABLE_WIDE_RX                := 1       full 18MHz to 1300MHz RX (though frontend not tuned over full range)
ENABLE_TX_WHEN_AM             := 0       allow TX (always FM) when RX is set to AM
ENABLE_CTCSS_TAIL_PHASE_SHIFT := 1       standard CTCSS tail phase shift rather than QS's own 55Hz tone method
ENABLE_MAIN_KEY_HOLD          := 1       initial F-key press not needed, instead hold down keys 0-9 to access the functions
ENABLE_BOOT_BEEPS             := 0       give user audio feedback on volume knob position at boot-up
ENABLE_COMPANDER              := 1       compander option (per channel)
ENABLE_SHOW_CHARGE_LEVEL      := 0       show the charge level when the radio is on charge
ENABLE_REVERSE_BAT_SYMBOL     := 1       mirror the battery symbol on the status bar (+ pole on the right)
ENABLE_CODE_SCAN_TIMEOUT      := 0       enable/disable 32-sec CTCSS/DCS scan timeout (press exit butt to end scan if disabled)
ENABLE_AM_FIX                 := 1       dynamically adjust the front end gains when in AM mode to helo prevent AM demodulator saturation - ignore the on-screen RSSI (for now)
ENABLE_AM_FIX_SHOW_DATA       := 1       show debug data for the AM fix
ENABLE_SQUELCH_LOWER          := 1       squelch settings more sensitive - plan to let user adjust it in the menu
ENABLE_RSSI_BAR               := 1       enable a dBm/Sx RSSI bar graph level
ENABLE_AUDIO_BAR              := 0       experimental, display an audo bar level when TX'ing
#ENABLE_COPY_CHAN_TO_VFO      := 1       not yet implemented - copy the channel into the VFO
#ENABLE_SINGLE_VFO_CHAN       := 1       not yet implemented - single VFO on display when possible
#ENABLE_BAND_SCOPE            := 1       not yet implemented - spectrum/pan-adapter

Some changes made from the Quansheng firmware

• Various Quansheng firmware bugs fixed
• Added new bugs
• Mic menu includes max gain possible
• AM RX everywhere (left the TX as is)
• An attempt to improve the AM RX audio (demodulator getting saturated/overloaded in Quansheng firmware)
• keypad-5/NOAA button now toggles scanlist-1 on/off for current channel when held down - IF NOAA not used
• Better backlight times (inc always on)
• Live DTMF decoder option, though the decoder needs some coeff tuning changes to decode other radios it seems
• Various menu re-wordings (trying to reduce 'WTH does that mean ?')
• ..

Compiler

arm-none-eabi GCC version 10.3.1 is recommended, which is the current version on Ubuntu 22.04.03 LTS. Other versions may generate a flash file that is too big. You can get an appropriate version from: https://developer.arm.com/downloads/-/gnu-rm

Building

To build the firmware, you need to fetch the submodules and then run make:

git submodule update --init --recursive --depth=1
make

To compile directly in windows without the need of a linux virtual machine:

1. Download and install "gcc-arm-none-eabi-10.3-2021.10-win32.exe" from https://developer.arm.com/downloads/-/gnu-rm
2. Download and install "gnu_make-3.81.exe" from https://gnuwin32.sourceforge.net/packages/make.htm

3. You may (or not) need to manualy add gcc path to you OS environment PATH.
   ie add C:\Program Files (x86)\GNU Arm Embedded Toolchain\10 2021.10\bin

4. You may (or not) need to reboot your PC after installing the above

Then you can run 'win_make.bat' from the directory you saved this source code too. You may need to edit the bat file (path to make.exe) depending on where you installed the above two packages too.

I've left some notes in the win_make.bat file to maybe help with stuff.

Credits

Many thanks to various people on Telegram for putting up with me during this effort and helping:

• DualTachyon
• Mikhail
• Andrej
• Manuel
• @wagner
• @Lohtse Shar
• @Matoz
• @Davide
• @Ismo OH2FTG
• OneOfEleven
• @d1ced95
• and others I forget

License

Copyright 2023 Dual Tachyon https://github.com/DualTachyon

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Example changes/updates

Video showing the AM fix working ..