In the first Blog-1, I had just started with the Enviro HaT but I did not have any idea of how to interface the Automation HaT or both the HaT's connected together

with Pico Hat. During the last days, I had plugged in the Automation HaT, and installed the required software, tried the demo examples, and tested their functional

working demo!

Also, one more task was to solder the Pico HaT Hacker on the 40-pin GPIO header and connect both the HaTs. There were some basic challenges to get both the

HaTs working together. I had questions in my mind before I get started.


1) How will both the HaTs be working plugged in together in the little space?

2) Can I only use the available sensors on the Enviro by just connecting the I2C wires? and plug in the Auto HaT in the main header?


I started by soldering the Pico HaT on the main header and the 40-pin male header on the second header. While connecting the Enviro Hat together with Automation

HaT there were initial errors to access the I2C sensor ltr559. The problem was that I was only connecting the 4-wire I2C sensors. The BME280 was working nice, the

ltr559 was showing up in the list of I2C devices but while trying to access the sensor the error was about Error No. 121, I/O error.

The solution was that I need to connect all the grounds and 5/3.3 V pins marked in the above picture.

Finally, I have both the HaTs working together with an additional DPS310 Temperature/Pressure sensor from Infineon connected with the Automation HaT I2C interface.

The next part is that I want to have more sensors at various places in the 1m3 space and there might not be a possibility to connect them over the same I2C interface bus

because of the limitation of available I2C addresses. The MQTT protocol with ESP could be one of the possible thing I could try to send sensor data from various places.