ZUMspot v0.4 & I2C on-board interface usage for OLED screen

[G0APM]

I note the ZUMspot (v0.4 in my case) HAT has convenient I2C interface header available.
Measuring shows 3.3V and GND go to the appropriate GPIO headers but SDA & SCL don't.

I successfully have an OLED screen operating connected directly to the GPIO pins (as type 3)
but am wondering if it's possible to use the more convenient ones on the modem board itself?
If anyone has used this method can you advise the requirements/setting please?

73

[KE0FHS]

Yes, you can use the I2C through-holes for an OLED display. On the v0.4 board, connected to the clock (SCL) and data (SDA) pins on the STM32 chip. On the v0.6 board, the SDA/SCL pins for OLED are connected to the GPIO pins.

On the Configuration page, for MMDVM DIsplay Type, select OLED. You can leave the other two display settings at their defaults (Port: /dev/ttyAMA0;
Layout: G4KLX).

Some settings notes:

• Set OLED type in Expert Editor > MMDVMHost > OLED section. 0.96″ = Type 3; 1.3″ = Type 6. After applying changes, reboot Pi-Star.
• Change OLED rotation in Expert Editor > MMDVMHost > OLED section > Rotate (0 or 1).
• Change between white text on black background (0) and black text on white background (1) in Expert Editor > MMDVMHost > OLED section > Invert.
• Thanks to Scott, VK7HSE, for this one: If your OLED display has garbled text, check your Display Level in Expert Editor > MMDVMHost > Log section. It must be set to 0.

P.S. Nice avatar!

[G0APM]

That's great!

I appreciate you taking the time to reply, it would have been easier than soldering directly
to the board. I have another ZUM board so next time I'll take that route.

73