How to connect an I2C display to VOXL

Table of contents

  1. Overview
  2. Hardware
  3. Target Software
  4. Usage
  5. Hardware Setup

Overview

Here at ModalAI, Inc. we like to use a small I2C display on our robot to give us some visual feedback on what is happening in, for example, the boot up sequence.

We are use a 0.96” 128x64 ssd1306 OLED display.

Here is a link to the one we use: Amazon page

voxl-dk

Hardware

  • Custom cable with the following pinout:
VOXL - J10, DF13-6S-1.25C connector I2C Display
Pin 1 - 3.3V VCC
Pin 2 - TX NC
Pin 3 - RX NC
Pin 4 - SDA SDA
Pin 5 - GND GND
Pin 6 - SCL SCL

Target Software

  • I2C Display Example Application: Download

  • Install the package to the target:

adb push i2c_display_x.x.x.ipk /home/root/ipk
adb shell "opkg install /home/root/ipk/i2c_display_x.x.x.ipk"

Usage

Once the software package has been installed you use the command i2c_display. If you do not supply an argument it will display the ModalAI, Inc. splash screen. Otherwise you can give it a one or two word phrase to put on the display. For example: i2c_display "TIME INIT"

Hardware Setup

  • Disconnect power from the VOXL
  • Connect the VOXL’s J10 to the i2c display using the custom cable described above
  • Reconnect power