N2IRZ RSSI Software
30APR2026

The accompanying software is intended for the N2IRZ RSSI display board, running on a Raspberry Pi Pico (RP2040). 
This software is free to use, copy and modify, but may not be used for commercial purposes without written permission of Donald Rotolo, N2IRZ.

To use this software, save it to the Pi Pico as "main.py".

The software in this archive is version 1.8, dated 13MAR2026.

NOTES:
* At startup, the LED insicators sweep twice to identify any non-functional LEDs
* If the two leftmost LEDs flash alternately, no radio jumper has been selected
* The leftmost green LED is always lit if the software is running.
* The leftmost red LED is typically lit always except when transmitting, but this can vary.
* At idle, additional lit LEDs indicate the local noise (QRM + QRN) level
* During receive, LEDs light to indicate received signal strength. This is typically +/- 3 dBm
** If YOU measure the RSSI Voltage from ANY radio, using a calibrated signal source, every 10 dBm from -80 dBm to -120 dBm, send that data to me for a free RSSI Kit.


# Version History:
    # 1.0 Initial release
    # 1.1 Development version never released
    # 1.2 Implements measured threshold values TAIT TM-8xxx
    # 1.3 14OCT2025: Removes external ADC voltage reference
    # 1.4 21FEB2025: Implementws peak-hold as coded by Nino Carillo KK4HEJ
    # 1.5 17MAR2025: Implements TK-x90 RSSI curtves and multi-radio capabilities
    # 1.6 27SEP2025: Adds a sweep at startup to verify LED function (KA2DEW)
    # 1.7 11MAR2026: Flashes green LEDs when RSSI input overvoltage is detected (KA2DEW)
    # 1.8 13MAR2026: Defeat slow rise for peak indicator, corrected value in TAIT voltage table (KA2DEW)
