ESP8266 Community Forum

I'm having a strange issue with a phototransistor. I have an OP804SL picking up IR pulses from my electric meter for power consumption monitoring. On the same ESP-12 I am running a nonparisitic OneWire bus with about 5 DS18B20s. Every 30 seconds the OneWire bus is rescanned for new devices--to facility hot plugging, a temperature request is executed, the 2 seconds later the temp is pulled from each sensor. When a meter pulse lands in the middle of OneWire activity, the phototransistor doesn't pull down enough to trigger an interrupt. I'm using an uno with serial plotter as a poor man's scope. I do use the internal pullup, and a strong 4.7K external pullup to help with noise. The OneWire bus has a 4.7K pullup as well.

I temporarily solved the problem putting a transistor in between, but that recently failed with the increased ambient sun light.

Can someone give me a clue as to what is going on?