I’ve been working on a project that uses I2C for Temps, Humidity, and 16x2 RGB LCD display,
(3) 1-Wire DS18B20’s and reads 2- analog voltages. Everything is working using a small breadboard.
I decided to use the Shield Shield since it provides a small prototyping area and the Adafruit (714) Display Shield seemed like a good choice. I discovered the when the Photon is plugged into the Shield Shield that it interferes with the Display Shield unless you use stacking headers, this raises the Display Shield by 3/4". A low profile pin connector by Mill-Max might may eliminate needing to use stacking headers.
All components are wired to the Shield Shield and everything is working except the 1-Wire devices, trying D2, D3, D4, D5, D6 and they all behave the same. About 1.5 seconds or so so after the firmware is loaded the pin controlling the DQ of the 1-Wire bus starts oscillating. The only difference I can find in the two setups is the TXB0108PWR Level Translators. Since the Breadboard setup up does not have level translators I’m wondering if I should remove them from the SS PCB. A note on the SS data sheet,… excessive capacitive loading and cause the auto direction detection to fail. The 1-Wire signal is plugged directly into D6 on the Photon header using a 5" breadboard patch wire. And that is on the 3.3V side of the translator. The breadboard setup also used a 5" patch wire for the 1-Wire bus and it is functioning properly… I don’t see for my application the need for the Level Translators but maybe I missing something.
Any ideas or suggestions?