Neo Trellis not detected using I2C_address_detect


Active member
I've just got a 8x8 Neo Trellis and soldered 2 out of the 4 boards together and then tested it using the i2c_address_detect script and its not detecting it:

I2C address detection test
Did not find device at 0x10

I have it connected to the Teensy 4.1 as follows:

SDA > 18
SCL > 19
VIN > 3.3V
INT > not connected as using the onboard connector

I've soldered the A0 pad together on the 2nd board but as far as I understand it it should be detecting the 1st board regardless of any dodgy soldering or address mistakes on the 2nd board.


#include <Adafruit_I2CDevice.h>

Adafruit_I2CDevice i2c_dev = Adafruit_I2CDevice(0x10);

void setup() {
  while (!Serial) { delay(10); }
  Serial.println("I2C address detection test");

  if (!i2c_dev.begin()) {
    Serial.print("Did not find device at 0x");
    Serial.println(i2c_dev.address(), HEX);
    while (1);
  Serial.print("Device found on address 0x");
  Serial.println(i2c_dev.address(), HEX);

void loop() {
Double check solder bridge on address select pads, the pic is unclear.

Try inserting 150R in SCL and SDA lines as close as possible to T4.1 SCL and SDA pins.
Its working now without me having to change anything, the i2c_address_detect script still doesn't detect it but when I loaded up the NeoTrellis example it lit up like a christmas tree, maybe something in the sketch needs to activate it.