When we last heard from out intrepid Simblee Breakout Shield, it was found to be using and open drain linelevel converter without pull-up resistors, and that’s against the law. Or, at lease against good judgement.
After a dual face palm, I found the TXB0108PWR chip, again from Texas Instruments. This one is a push-pull line level converter, so no pull up resistors are needed on the GPIO. The pin-outs are close between the two chips, but not exact. Too bad. It would have been nice to just drop in the different chip. But, the I2C still needs pull ups anyway. ,I gave it a TXS0102 open-drain converter, and pull-ups and ordered the revised boards.
After I build and test this one, I’ll move on to the next version. I want to dispense with the breakout, and put the Simblee chip directly on the shield. I’m also going to use Silego chips for the line level converters. If you haven’t heard of the Silego chips, they’re very small mixed-signal programmable logic. I’ll write more about them later.
Run Fourier, run