Guru
Joined: 11/02/2018
Location: AustraliaPosts: 2375
| Posted: 04:14am 09 Jan 2022 |
" it only enables the DATA OUT pin to pull the line high when CS is low, when DATA OUT is low it is not actively pulling the line low. A pull down resistor (to 0v) on the transistor collector would help."
I think mine works without the pull down resistor because the emitter can act as a collector and vice versa, with much reduced gain. The reverse beta is typically around 1/10 of forward. This only works at low voltages as the B-E reverse breakdown voltage is only 6 to 8V.
If you do use a pulldown resistor perhaps it could go to LCD-CS instead of 0V. Tried it on mine and it works as before.