From 537ddf006b740e6a33d15427d05a4cfb8b18861f Mon Sep 17 00:00:00 2001 From: eleccoder <9162301+eleccoder@users.noreply.github.com> Date: Sun, 14 Nov 2021 21:14:57 +0100 Subject: [PATCH] Correction and minor improvements --- README.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 8d5201c..29a59a7 100644 --- a/README.md +++ b/README.md @@ -1,9 +1,9 @@ GitHub last commit # raspi-pico-aprs-tnc -A TX-only [TNC](https://en.wikipedia.org/wiki/Terminal_node_controller) (Terminal Network Controller) to generate the [AFSK](https://en.wikipedia.org/wiki/Frequency-shift_keying#Audio_FSK) audio tones for [APRS](https://en.wikipedia.org/wiki/Automatic_Packet_Reporting_System) (Automatic Packet Reporting System) messages using a [Raspberry Pi Pico](https://en.wikipedia.org/wiki/Raspberry_Pi) microcontroller board. +A TX-only [TNC](https://en.wikipedia.org/wiki/Terminal_node_controller) (Terminal Node Controller) to generate the [AFSK](https://en.wikipedia.org/wiki/Frequency-shift_keying#Audio_FSK) (Audio Frequency-Shift Keying) audio tones for [APRS](https://en.wikipedia.org/wiki/Automatic_Packet_Reporting_System) (Automatic Packet Reporting System) messages using a [RP2040](https://en.wikipedia.org/wiki/RP2040) microcontroller on a [Raspberry Pi Pico](https://en.wikipedia.org/wiki/Raspberry_Pi) board. -An analog line-out audio signal will be generated by a filter connected to GPIO-pin 'GP0' which provides the binary PWM signal. You can probe it by a scope, listen to it by using an audio amp, or connect it to any RF transceiver to send it on the air (ham radio license required). +An analog line-out audio signal will be generated by a band-pass filter connected to GPIO-pin 'GP0' which provides the binary PWM signal. You can probe it by a scope, listen to it by using an audio amp, or connect it to any RF transceiver to send it on the air (ham radio license required). ![AFSK scope screenshot](https://github.com/eleccoder/raspi-pico-aprs-tnc/blob/main/doc/img/afsk_scope.png)