Touch Display Overview
Let's take a closer look at the Red Vision Touch Display for RedBoard and the hardware included on it.
2" Capacitive Touch LCD
The Touch Display Board has a 2", 340x240px resolution capacitive touch LCD.
Connectors
R3 Headers
The Touch Display comes with male headers soldered to plug directly into a SparkFun RedBoard (or other compatible development board that uses the R3 footprint). These are 2 8-pin, 1 10-pin and 1 6-pin headers. These headers break out all the required pins for running and controlling both the display on this board as well as pins for the connected camera board.
Camera Connector
The Touch Display board has a 2x10 female connector to connect to the Red Vision Camera Board (or other compatible camera board, refer to this list for supported hardware). Note, the Camera Board has a 2x9 header so when connecting the two, make sure to align it to the side near the Qwiic connector. We cover this in more detail with photos in the Hardware Assembly section further on in this guide.
GPIO Expander
The Touch Display includes a PCA9534PW GPIO expander to control several I/O (input and output) pins from the display and camera over I2C. Users can interact with the GPIO expander using the SparkFun PCA9685 Python package.
LED
The sole LED on this board is a red Power LED to indicate when the board has power.
Solder Jumpers
The Red Vision Touch Display for Pico has a large amount of solder jumpers so we'll cover them in subsections. If you're not familiar with how to use solder jumpers or want some tips, check out our working with jumper pads and PCB traces tutorial.
GPIO Expander Jumpers
The INT jumper controls whether or not the GPIO expander's interrupt (INT) pin connects to A2 on the RedBoard. The jumper is OPEN by default. Close the jumper to connect the interrupt pin to A2 for software control of the GPIO Expander.
The set of jumpers labeled A0, A1 and A2 control the I2C address of the GPIO Expander. All three jumpers are OPEN by default to set the GPIO Expander's address to 0x20. Closing different combinations of these jumpers lets users select from eight I2C addresses. The table below outlines the different options to change the address. You can also refer to the schematic for more information.
| I2C Address | A0 State | A1 State | A2 State |
|---|---|---|---|
| 0x20 (Default) | Open | Open | Open |
| 0x21 | Closed | Open | Open |
| 0x22 | Open | Closed | Open |
| 0x23 | Closed | Closed | Open |
| 0x24 | Open | Open | Closed |
| 0x25 | Closed | Open | Closed |
| 0x26 | Open | Closed | Closed |
| 0x27 | Closed | Closed | Closed |
Other Jumpers
The last jumpers we haven't covered are labeled PWR and I2C. The PWR solder jumper completes the Power LED circuit and is CLOSED by default. Open the solder jumper to disable the Power LED. The I2C jumper pulls the I2C pins (SDA/SCL) to 3.3V through a pair of 2.2kΩ resistors. Open this three-way jumper to disable the pullup resistors on the I2C bus if necessary.
Board Dimensions
The Red Vision Touch Display for RedBoard measures 2.10" x 2.35" (53.34mm x 59.69) to fit the R3 footprint.
