That´s the latest Version of the IO Board. As the name says, it features a cheap OLED Display, that is connected via (secondary) I2C Bus.

Opposite to LCD IO Board, it has an additional 3,5mm Jack (Send PA), which enables you to control external Power Amplifier with it. It also has an Interface to connect USB-Serial Converter (like this one) to control it over CAT. On top of that it has an ISP Interface, so you do no longer need to disassemble the rig to upgrade the firmware.

The Disadvantages of this IO Board are:

  • takes 5mA more Current
  • Obviously smaller Display (with some Details still missing on software side)

Gerber Files and BOM

PCB Files (for direct Upload to JLC PCB): OLED_V2_Gerber

Schematic: uSDX-IO-OLED_Rev2_1

iBOM (checklist): uSDX-IO-OLED_Rev2_1


The SMT Resistors and Capacitors are all in 0805 Size, with no special requirements. Ceramic caps for 16V and more rating is OK. Resistors are only Pull up´s…. Completely uncritical.

D1/D2 Standard 1N4148 Diodes

SW4 (rotary encoder) use EC11B13 (Unlike other rotary encoders, this one is known to work without trouble and comes at a reasonable price)

SW1-SW3 you can use for example these

MK1 (on-Board Mic) for example this one (watch for polarity !!!)

J4,J5,J6 use these

J1 and J2 are male jumper connectors, nothing special

J3 is Place Holder for OLED Display, like this one (if you buy another one, watch for the right order of the Pins)

J7 and J8 are Female Pin Sockets, with bent contacts for horizontal mount. Nothing special.

Just solder everything in. The OLED Display can either be soldered directly or you can use another female jumper header, so you can change it. The PCB features holes, to mount the OLED Display with Spacers if needed. threading is M2, chose height according to your needs.

J1,J2,J7 and J8 are soldered on the Bottom Side of PCB. Rest is on the Top Side !