#Setup external usb audio interface software#

WITH : the receiver must provide a close contact when NO signal. voltage is 5V, even if there is a 5V Zener protection on board. WITHOUT : the receiver must provide a voltage when NO signal.

#Setup external usb audio interface software#

The Squelch input drives transistor Q1 to pin 48 VOLDN and tells the software that a carrier is present. The jumper JP4 can be used to interrupt the PTT line in removing this jumper and/or wiring a front panel switch. The PTT function is done via CM119A pin 13 GPIO3. The Watchdog is preventing a steady carrier situation if the controler software crashes. Transistor Q4 is not driven anymore and locks the PTT line via Q3 which is the PTT switch. As soon as the LED0 stops blinking, the Watchdog puts the NE555 output in a LOW state. This LED0 output is also used to drive a Watchdog build around a NE555 triggerable astable. Blinking shows a USB dialog and steady that the chip is powered and waiting. The LED0 output on pin 12 drives the Led HB (heartbeat) that monitors the CM119A state. It has an internal oscillator with an external 12 MHz crystal. The heart of the interface is a CM119A chip that has a USB transceiver, voice DA + AD converters and 8 GPIO ports. The output is protected by a fuse F1.Ī jumper can select the power source for the board the internal PS or via the USB A connector. The input is max 30V and it can furnish 3A. The board has its own power supply build around a small DC-DC buck converter that can power the interface and an external board via the USB1 A type connector. GPIO4 to GPIO8 available on onboard pin connector.DSUB- 9 female connector for RADIO inputs/outputs (PTT, SQ, AF TX & AF RX).Port USB A to power an external board like a raspberry via a USB cable (USB C, etc.).Port USB B for IN/OUT and connexion to computer or Raspberry board.2mm power Jack to power the onboard 5V/3A power supply (max 30V input).5 GPIO available, software programmable.PTT output can be cut via jumper or switch (for tests, relaying OFF, etc.).Squelch level jumper selectable, ground or high level (open squelch).Left/right transmit audio channel jumper selectable.4 monitoring LEDs, Heardbeat, Squelch, PTT & OK.Watchdog locking the PTT output in case of communication problem with the controler.Powered via USB port or onboard stepdown regulator, jumper selectable.Onboard USB sound card compatible USB 2.0 and 48 kHz sampling rate.So, the idea to build a newer board with an onboard USB audio chip was born.īeing retired, i found the time and mood to develop a new interface board using the same chip CM119A which is a small LQFP-48 case. With time, this solution appeared to be not the best choice for different reasons. It was using a cheap USB audio stick that we modified and plugged on my board. In order to digitalize the audio signals and interface them with the repeaters, i developped a small interface board some years ago. Our corsican repeater network TKNET uses the Asterisk software for the routing and communication between nodes.