MicroP25RX and Wio Firmware

 FCC Search DB Files Unzip these files to the uSD card for the Zip Code Search function. The fcc_user.csv file is user-editable entries for the search.

FW Update Instructions
MicroP25RX_FW_Win_V2_2.pdf (updated 12-07-22) -goldmyne99

Adding A Channel - Quick Start Guide

MicroP25RX CC adding (12-07-22) - goldmyne99

Reference Doc For RGB565 Display Colors

RELEASED FIRMWARE (ships with this version)

MicroP25RX FW 2023-01-23-02 

Wio Terminal MicroP25RX FW CURRENT-2023010101.UF2 (use with 01-19-02)

Wio Firmware Source (github)



MicroP25RX FW 2023-01-30-01 

Wio Terminal MicroP25RX FW CURRENT-2023010101.UF2 (use with 01-30-01)


  • add ENC_FAST_DET to [GLOBL CONFIG] section. This option will immediately disable encrypted audio if detected (may cause some false detections in low SNR conditions).


  • Always start in MONITOR mode.
  • Revert one change to ASIC init code


  • Improvements to DSP and RF ASIC init code.


  • minor update. Fixed P1P2_INDICATOR color in the bacukp/restore functions.


  • increase audio gain before AGC. (higher compression).


  • Microp25RX fw update. Read Config and Write Config is now supported by the MicroP25RXMon application over USB. Versions are 01-05-02


  • Changes preparing for configuration editing via the MicroP25RXMon software.


  • Revert code back to 0101-06 state in attempt to fix new audio related issues for a user.


  • audio related changes.


  • P25 P1 & P2 voice synthesis improvement.


  • Update to MicroP25RX and Wio firmware. Added LINE0_BG and LINE0_FG colors to the [GLOBL_CONFIG] section of the backup ini file. These define the foreground and background color of the new top-line button function description line.  (default of white background with black text).


  • 0101-02  Another change to P1/P2 audio.
  • Revert some recent changes to P25 P1 audio.


  • Fix a new bug in P25 P1 audio.


  • remove IQ normalization code in the receiver firmware that was messing up RSSI calcs. The normalization is done in the MicroP25RXMon application for visualization purposes.


  • P1 and P2 audio improvements.
  • Support for the new MicroP25RXMon monitoring application.


  • WIO FW:  add top-button mode header to display for all modes.


  • 12-27-01 Fix issue with P2 encryption detection caused by 12-26 releases.
  • clear audio output buffer on encrypted audio detect. add ENC_TIMEOUT (millisconds) to [GLOBAL_CONFIG] section.
  • Attempt to fix issue with muting of P25 P2 encrypted transmissions.


  • P2 sync word detect allows a single bit error. BACKUP ini file allows for 1.4 AUDIO_VOL format value to allow lower volume levels.
  • WIO FW update 12-23-00 New AUDIO menu LOW VOLUME menu for lower volume applications. (-30 dB to +6dB range). Thank you goldmyne99!


  • 1222-04 Display Tone-outs longer on the display. Show frequency of tones in Hz on line 2 of the display (in addition to the index values on line 1).
  • 1222-03 Reset tone-b-timeout after we detect tone-a, but are still in the process of receiving tone-a. This should prevent a situation where tone-b-timeout occurs causes a detection miss on an unusually long tone-out.
  • 1222-02  FIX a bug that caused two-tone IDX readings to be off by 1. update: Every value from 1-72 was validated with signal generators to be correct in this release.
  • Minor improvements to two-tone decode.


  • Two-tone detection now supports multiple tone-out pairs per call. The display is in P25-group index format ( index 1-72) instead of frequency.


  • WIO FW: When saving the global config (hold top-middle button for > 3 seconds), there is a brief message displayed "Wrote Config". The new LCD backlight brightness value is saved to the Wio flash memory configuration.


  • Merge LCD backlight adjustment code from goldmyne99 fork. Use the joystick up/down buttons in monitor mode to adjust the LCD backlight brightness.


  • 1217-07 - Fix minor display glitch on line 2
  • Fix P1/P2 audio stutter issues (verified by users)
  • P1/P2 Two-tone audio frequency decodes display on Wio Line1. Display is currently in Hz. Index into table will be added later.

2022-12-15 (-03)

  • Wio FW 1215-05: Fix issue with color9,color10,indicator. Implement MENU FG,BG colors.
  • Display colors are now defined in the backup file. The colors are stored as HEX RGB565 values. You can reset to default values if you set the default fg equal to the default bg. See the RR forum for more details.

2022-12-15 Wio FW:  On the signals page, when setting the VGA to AUTO, the current value for the gain is displayed next to AUTO. When saving the gains with the top-middle button, this value will be used to set the VGA gain to a fixed value.


  • Fix bug with TG Zone mode selection
  • add P2_LSM parameter to [GLOBAL_CONFIG] section of the backup ini file. When set to 1, then P2 voice always uses LSM demod even if the control channel is set to FM demod. Set to 0 to disable this option. When set to 0, P2 will use the sites configured demod mode.


  • Another small update to the P2 channel filter and decode.

2022-12-09 Wio FW Update.

  • Selecting Monitor Mode toggles between standard view and TG History view. Changes submitted by goldmyne99. Thank you!


  • Improvements to sensitivity due to changes in P1 and P2 digital filters.
  • Fix lock-up issues when changing DEMOD / Gains for a newly added site.


  • Several improvements to the zip code search function / learn mode.


  • Update both MicroP25RX and Wio firmware. There is a new LOCK_NAC option in the BACKUP/RESTORE. The value has to be manually changed in the backup file. After updating the firmware, create a new backup. Edit the LOCK_NAC value to be 1 for all sites that have a valid NAC value. This will prevent any updates to the NAC. This can help improve P2 decodes in low SNR environments and also prevent the device from entering "LEARN MODE" due to an invalid NAC change. On the display, an 'L' will be shown next to the NAC value for locked values. 'U' for unlocked.


  • Fix issue with 'skip' button when receiving TDMA/P2 voice.


  • Allow TG Priority Interrupt during conversation when scanning is enabled (roaming mode is not OFF).


  • Wio Display. Fix display flicker when drawing the the keyboard. Shouldn't affect function.


  • Fix DEMOD change lockup / Write Config lockup when adding a new site.


  • Free up more Wio Terminal RAM.


  • Increase requirements for NAC validation.
  • Wio Firmware Update.  - Potential fix for elsuive bug that causes application flash to be lost on the Wio. Please report if it happens with this or newer version.


  • Fix for p25rx alias file import


  • Show demod mode on the signals display
  • Learn mode timeout is 30 seconds after enabling learn mode. Enabling learn mode will force re-learning CC information. During the learn mode timeout period, voice-traffic grants will be ignored. Learn mode is automatically enabled after manually entering a new frequency.


  • Fix issue with changing demod mode.
  • Show ENCRYPTED brielfly on display when encrypted transmission is detected.
  • Improved TDMA audio decode from version 11-23-02


  • This version may improve P2/TDMA decodes. If you give this alternate fw a try, then please report results via email. Initial feedback has been good. Thank you.


  • Fix issue with "allow unknown talk groups". Disable TG that have alpha tag of UNKNOWN when "allow unknown TG" is disabled.
  • In SIGNALS mode, top-left button enables/disables scanning (if roaming mode enabled), top-middle button save gain config, top-right button changes demod mode.


  • Fix gain control, save configuration
  • Add SD Card Formatter to the SD menu


  • Added adjustable gains per-site
  • Fixed DSD TG import issues

Select the site you want to change gains for, then press the mode button (joystick press-in). Select SIGNALS

Joystick up / down selects the gain you want to change.
Joystick left / right, increase / decrease the gain

The gain ranges for LNA, MIXER, VGA is 1 - 15. If you go above 15, then it switches to AUTO mode for that gain.

After configuring the gains to achieve the best EVM / performance, then press the TOP-MIDDLE button to save the configuration for that SITE. The gains are unique to WACN-SYSID-SITEID-RFSSID



  • At least 10x speed up when importing TG, ALIAS and when doing a RESTORE.
  • Much improved importing of DSD TG files. Including priorities, and Normal/ L/O status. Also allows spaces in the fields.
  • Fixed the lockup bug when changing DEMOD for the first time after flash reset to defaults. (not 100% sure this is fixed. needs more testing).
  • Allow changing of frequency with the joystick when voice is decoding