Raspberry Pi Stack Exchange
Raspberry Pi Stack Exchange

Questions tagged [hat]

A "hat" is an add on board designed specifically to fit on top of the pi via the GPIO header. They have a small EEPROM chip which is used to configure them, but may be built to serve any purpose.

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Is it possible to use an additional HAT with the Raspberry Pi PoE HAT

I recently got a Raspberry Pi 3 Model B+ and the official Raspberry Pi PoE HAT. It is powering it from my switch fine but I am wondering if it is possible to also use an additional HAT with it? The PoE HAT seem to allow pins to pass all the way…
njh
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Why does the Sense Hat / Astro Pi show the wrong temperature and humidity?

I recently bought the sense-hat, previously called astro-pi. Unfortunately the temperature shows 28 to 31 degrees Celsius from both temperature sensors on the board. They often show around 30 degrees right from the start when the raspberry pi boots,…
ElectroDxvid
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How to detect what kind of HAT or GPIO board is plugged in - if any?

I am setting up some Raspberry Pis for use in demos to colleagues, in order to show off capabilities of the Pi itself, and of some of the add-on boards that are available. I would really like to be able to maintain one cron-job/start-up script for…
Clare Macrae
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PoE hat fan activation on OS other than Raspbian

I'm aware that the only officially supported OS that the PoE hat works on is Raspbian. I can confirm that both my hats work, and that the fan does switch on and off if I have Raspbian installed on the SD card the Pi is booting from. Currently,…
Larnu
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How to use a GPIO pin after I put on a HAT?

I got a Speaker pHAT for my Pi Zero. According to the pinout, it only uses 5 GPIO pins, so plenty of room to add something else. The problem is, I'm not sure what's the best way to physically attach something after the hat is attached. Two solutions…
fstanis
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How to approximate room temperature in a better way

I've just bought an Enviro pHAT. The temperature sensor on my pHAT reads around 31 degrees Celsius for my room This sensor is close to the Pi, so it also gets a heatwave from the CPU Is there a better way to approximate the actual temperature?
R Harrington
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Stepper Motor Hat v0.1 - pre-soldered version

I am pretty new and have installed the referenced HAT. I followed the instructions, but it is not detected. I have power and a green LED on the board and when I turn it on and off the servos jump a bit, so it seems like it is physically OK. I have…
CaptStephan
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Establishing how to power on a HAT using GPIO

I have a combined GSM/GPS HAT and a Pi Zero. I can turn on the HAT manually using the power button, but would like it to power on at boot via /etc/rc.local. I can do something along the lines of this, within /etc/rc.local: echo "17" >…
Clive van Hilten
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Same lipo power source for raspberry pi and motor hat

I am building a rover and would like to power the Raspberry Pi and the Motor HAT with the same power source. I want to use a 2500 mAh LiPo battery for a long play time. My DC motors work at 6V-9V. How can I do this?
Raspi_roverman
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i2c_arm bus initialization and device-tree overlay

I've built a Pi1541 HAT, just for fun, and am now playing with the device-tree autoconfiguration in Raspbian. I've made an overlay that autoloads during boot, based on the EEPROM contents, and that overlay defines the five buttons, the LED and the…
Hans Liss
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RPi4 won't power on from 5V if any load is present on 3V3

The short version: Raspberry Pi 4B, rev 1.1, doesn't turn on when provided with 5V on the pins 2&4 if any load is present on the 3V3 (pins 1&17). However, powering the Pi from a USB-C source (with the same load on 3V3) works as intended. The longer…
MJBogusz
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setup wifi hotspot with 4G hat

I have bought a 4G hat for my raspberry pi 3B+ (the sim7600 waveshare for europe) and followed these instructions for setup. It is running the latest version of raspbian and I have internet on the raspberry through the USB interface (wwan0), which…
Jarrr
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GPIO relay signal cross turns to all relays staying on after Darlington added

I have 4 Sunfounder 2 channel relays 7 of which that I'm using to control some things on my aquarium. I suspect that I may have wired them up wrong somehow though. The behavior I'm seeing is as follows; if I open either Drain Pump/Fill Pump…
Brad W
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No response from RFID HAT

Model: Raspberry Pi 3 Model B Vi.2 HAT: RaspberryPi-B1 v1.3 I just bought RaspberryPi Hat RFID/NFC board (RaspberryPi-B1 from ib technology). I've spent all day trying to get a response from it, but still no luck. If I shortwire my UART rx and tx…
BjarkeHou
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pHAT DAC 3.5mm solder pins

Like many others, I have been working on a handheld gaming system using a Raspberry Pi Zero. One of the downsides of doing this, however, is that it has no sound built in, other than through the HDMI port. I have looked into getting the GPIO pins to…
thatoneguy245
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