Connect multiple 2.8" TFT Touch Shield for Arduino
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james219
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- Joined: Fri Jul 30, 2021 10:22 am
Connect multiple 2.8" TFT Touch Shield for Arduino
Is it possible to connect 3 or 4 2.8" TFT Touch Shields to a single Arduino Uno?
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dastels
- Posts: 15820
- Joined: Tue Oct 20, 2015 3:22 pm
Re: Connect multiple 2.8" TFT Touch Shield for Arduino
In theory, possibly. In practice it's likely not the best approach.
Each TFT would need dedicated CS, DC, and backlite pins (connected to #10, #9, and #3), and each resistive touch controller would need a dedicated CS pin (connected to #8). The capacitive touch is harder since it's I2C and each would need a separate address and that doesn't seem possible so you'd have to use an I2C multiplexor such as https://learn.adafruit.com/adafruit-tca ... r-breakout. Interrupts from the touch controllers would have to be dealt with. If it's open-collector then you could connect them together and poll the controllers when one of them interrupts. If it's not open-collector you'll need to combine them with a big AND gate.
A completely different consideration is whether the UNO has enough power and memory to support multiple displays.
Dave
Each TFT would need dedicated CS, DC, and backlite pins (connected to #10, #9, and #3), and each resistive touch controller would need a dedicated CS pin (connected to #8). The capacitive touch is harder since it's I2C and each would need a separate address and that doesn't seem possible so you'd have to use an I2C multiplexor such as https://learn.adafruit.com/adafruit-tca ... r-breakout. Interrupts from the touch controllers would have to be dealt with. If it's open-collector then you could connect them together and poll the controllers when one of them interrupts. If it's not open-collector you'll need to combine them with a big AND gate.
A completely different consideration is whether the UNO has enough power and memory to support multiple displays.
Dave
Please be positive and constructive with your questions and comments.