I2C timeout with OLED display on Pico

Yes, it's really strange. Just looked at the datasheet: http://www.embeddedadventures.com/datasheets/SSD1306-Revision%201.1%20(Charge%20Pump).pdf

See 8.1 MCU Interface selection. It may well be that your OLED is in 3 wire SPI mode, not I2C. It might correlate with what one of the comments on the hobbyking page said:

OK. After some experimenting, this display works actually fine with some caveats ! Multiwii uses its own i2c libraries and this display will work with these. However this board doesn't connect SDAin and SDAout and hence will not work with standard Arduino libraries using the wire library ... Luckily, there is an easy fix ! Just put a solder bridge between pins 19 and 20 of the flat cable going to the OLED and everything works :-) The i2c address is 0x3C and google for "GOFi2cOLED" and you will find a very good Arduino library that works 100% with this display :-) I'll post a picture under the files section of the hack to solder pins 19 and 20. Might be good that HobbyKing upgrades the board with these pins properly connected ... Good luck.

I actually have a board that's like that - this one: http://www.embeddedadventures.com/oled_display_128x64_OLED-12864-WHITE.html

So I'll see if I can come up with a 3 wire SPI version - just shorting those pins might be easier though!