# Automation Hat - i2cdetect -y 1 **URL:** \ **Category:** Support\ **Created:** [September 20, 2017, 10:25pm UTC](https://forums.pimoroni.com/t/automation-hat-i2cdetect-y-1/6013 "2017-09-20T22:25:39Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![CliffB](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@CliffB](https://forums.pimoroni.com/u/CliffB)\ **Post date:** [September 20, 2017, 10:25pm UTC](https://forums.pimoroni.com/t/automation-hat-i2cdetect-y-1/6013/1 "2017-09-20T22:25:39Z")
I’ve just installed my automation hat and enabled I2C support on the pi 3 using raspi-config. As I’m not intending to use python but rather write my own code in C I haven’t run the pimoroni install scripts. I ran i2cdetect -y 1 and the output correctly showed a device at 0x48 (I understand that this is the ADC). Having read the pin out information I believe that the three LEDs are driven from an SN3218A device which is located on the I2C bus at 0x54. Should I be seeing this reported with the i2cdetect command? I’ve not tried sending any I2C commands yet but simple gpio commands using pigpiod correctly toggle the relays and open collector outputs so I believe the board to be working. Any assistance gratefully received. Cliff ---
**Author:** ![pi2003](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/pi2003/32/1613_2.png) [@pi2003](https://forums.pimoroni.com/u/pi2003)\ **Post date:** [September 21, 2017, 6:08am UTC](https://forums.pimoroni.com/t/automation-hat-i2cdetect-y-1/6013/2 "2017-09-21T06:08:16Z")
I don’t think so because the sn3218 is write only. ---
**Author:** ![CliffB](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@CliffB](https://forums.pimoroni.com/u/CliffB)\ **Post date:** [September 21, 2017, 9:29am UTC](https://forums.pimoroni.com/t/automation-hat-i2cdetect-y-1/6013/3 "2017-09-21T09:29:49Z")
Thanks for the reply. After more reading I came to the same conclusion that as the device is write only a non invasive read command won’t elicit a response. I re-ran the i2cdetect command with the -q flag (use SMBus “quick write”) added and the device did show up.