JUMA TRX2 microcontroller in the DDS board contains two serial com interfaces called UARTs. UART#1 is connected to JUMA TRX2 back plate RS232 connector. UART#2 signals are available at the connector J1 on the DDS board. Operation of RS232 interface (UART1) can be selected from TRX2 Config. RS232 interface can be used for TRX2 controlling with PC or for Voice memory option control. TRX2 RS232 port can not be used for both functions at the same time.
JUMA-TRX2 firmware version 1.03 supports UART2 usage for Voice Memory option control leaving UART1 for general TRX2 control.
Controlling device can be PC or JUMA-KB1 as with RS232 interface. UART2 speed is fixed 9600 bd and UART2 can only be used for Voice memory control. Users can implement their own cabling from DDS board J1 connector to controlling device. Bellow there are two different suggestions how cabling can be done.
This alternative of course limits AUX connector usage for its original functions(I/Q out or PTT signals). Wiring is however very simple. Remove jumpers from main board AUX config block J5. Connect wires from J5-3 to DDS board J1-3 and J5-4 to DDS board J1-1.
Cable can be made from scrap PC harness
DDS board J1 – Main Board J5 cable routing
Detail of DDS board connector. User should watch for possible clearance/insulation issues with the Voice Memory board
of Main Board J5 connection. Jumpers are saved on single pin(no connection)
Check that all plugs fit side by side. Leave enough room for antenna BNC connector
Solder 1nF RFI filter capacitors between 3,5mm jack lugs .
Detail picture how to make DDS board J1 connector
There is not much space behind the Voice Memory board.
of the UART2 cable. Do not leave cable lying over the RF LPF filters.