Merge branch 'master' of https://github.com/sh123/codec2_talkie

README.md

@@ -22,12 +22,13 @@ This minimalistic Android application is a digital voice frontend for your radio
 # Suitable radios and modems
 - Tested, works:
   - LoRa modem (BT): https://github.com/sh123/esp32_loraprs
-- Tested, unstable:
+- Tested, works, but not too stable:
   - AFSK1200 PicoAPRS (USB): http://www.db1nto.de/index_en.html
   - AFSK1200/GMSK9600 Kenwood TH-D74A (BT): https://dl1gkk.com/kenwood-th-d74-bluetooth-packet-radio-setup/
 - Could work, needs testing:
   - AFSK1200 MicroModem (USB): https://unsigned.io/micromodem
   - AFSK1200/GMSK9600 Mobilinkd TNC3 (BT/USB): https://store.mobilinkd.com/products/mobilinkd-tnc3
+  - nRF2401L01 2.4 GHz (USB): https://github.com/sh123/nrf24l01_arduino_kiss_modem
 
 # Related Projects
 - Codec2 codec: https://github.com/drowe67/codec2
@@ -36,10 +37,10 @@ This minimalistic Android application is a digital voice frontend for your radio
 - iOS Codec2 wrapper: https://github.com/Beartooth/codec2-ios
 
 # FAQ
-- Gaps in received audio
-  - If indicator often changes between RX/IDLE on the receiver side when sender and recipient are close by then 
-    - most likey you do not have enough bandwidth, use higher throughput modem mode, for LoRa modems you need approximately 170% of data rate for the given codec2 bitrate
-    - modem goes into RX state too fast after sending first packet, increase TxTail parameter for your modem, so it will longer TX tail before switching to RX
+- Gaps in received audio, indicator often changes between RX/IDLE on the receiver side when sender and recipient are close by then 
+  - most likey you do not have enough bandwidth, use higher throughput modem mode, for LoRa modems you need approximately 170% of data rate for the given codec2 bitrate, AFSK1200 modems should work at 450 bps codec2 mode, 700 bps might work, but not on all modems
+  - modem goes into RX state too fast after sending first packet, increase TxTail parameter for your modem, so it will longer TX tail before switching to RX
+  - if you are using LibAPRS based modem, set TxTail and TxPreamble programatically by using `APRS_setPreamble` and `APRS_setTail` methods as it does not seem to set these values from `CMD_TXDELAY` and `CMD_TXTAIL` KISS commands
   
 # TODO
 - Parrot mode, so speech coming from aether will be transmitted back (testing or digirepeating)