Hot answers tagged

5

That's the main problem with the Enviro pHAT, and the SenseHAT for that matter - proximity to the Pi affecting results. You're better off getting a Dallas 1-wire temperature sensor, preferably one with a long cable (such as, and this is just an example, the one contained in CamJam EduKit 2), or extend one without a lead by using jumper cables. This will let ...


5

Having read through the very helpful earlier comments and answers from Steve Robillard and Ghanima: /proc/device-tree/hat/product If /proc/device-tree/hat/product exists, you have a HAT attached and loaded - and that file contains the name of HAT. Here are some sample outputs: Display-o-Tron HAT cat /proc/device-tree/hat/product Display-o-Tron HAT ...


4

You will quickly face 2 problems : voltage and current. Voltage You battery produce 3.7V, the Raspberry use 5V, your motor 6-9V. You will basically needs two DC-DC step-up voltage converter to produce 5V and 9V from 3.7V. Current Now let's look if your supply provide enough current : The raspberry pi3 needs 2.5A at 5V and the converter is said to have a 95% ...


4

Ripping off SteveRobillards excellent comment: Use the HAT's I2C EEPROM The Raspberry Pi Blog points for HAT specification to GitHub where both documentation and software tools (eepromutils) for manipulation are available. README.md: The ID EEPROM contains data that identifies the board, tells the B+ how the GPIOs need to be set up and what hardware ...


3

I didn't get any answers, so I tried the random things method. It seems to work now and I have the addresses needed for the servos from ic2detect. Solution: you MUST boot up the Pi with the HAT installed but the power OFF. Then put the power to the HAT and the Pi seems to suddenly recognize the device. Not sure why at all, so I can't provide a more ...


3

You can buy stackable headers, which you could solder to the PoE HAT. You could probably use without soldering as the PoE HAT seems to make no use of the Pi GPIO. Any HAT mounted on top of the PoE HAT would impede the fan airflow, but as there is little evidence a fan is required this may not be a problem.


3

If you really don't want to extend the temperature sensor away from the Pi, it may be possible to compensate for the effect of the CPU. This post on yaab-arduino.blogspot.co.uk outlines an attempt at this in Python, using a moving average of the readings from both the temperature and pressure sensors (the pressure sensor can also measure temperature): ...


3

I'm using Ubuntu Server 20.04 LTS. The dtparams setting does not work, instead you need a udev rule. The fan config is in /sys/class/thermal/cooling_device0/, if you cat /sys/class/thermal/cooling_device0/type, it should be "rpi-poe-fan". Once you've confirmed that, use this udev rule as an example: SUBSYSTEM=="thermal" KERNEL=="...


3

It's not possible because there's no way to change the SPI chip select pin from CE0. https://www.raspberrypi.org/forums/viewtopic.php?t=227520 https://www.raspberrypi.org/forums/viewtopic.php?t=247569


3

The official design specification for a Raspberry Pi HAT hasn't changed since 2014 when the current form-factor was launched with the RPiB+. There's no hardware reason why a HAT for a RPi2B won't run on a RPi4B. The thing that may need to change is the software driver as 32-bit Buster is a bit different to Jessie. The RPF/RP(T)Ltd. folks have just launched ...


3

There is nothing in HAT requirements about supplying a machine-readable list of sensors. Therefore, there is no generic methods to list sensors on a HAT: even if such a method exists, it will be manufacturer-specific at best and HAT-unique at worst. HAT EEPROM contains either a device tree overlay or a name of such overlay in an external file. See if ...


2

Looking at the image of the device here, hopefully reproduced below: It ought to be possible to unsolder the five surface mount connections that attach the 3.5 stereo socket to the PWB and connect some skinny wires to the pads which (after bonding the wires with some hot-melt glue to reduce the chance of the wires being yanked off the PWB and ripping the ...


2

This page in the documentation (section 3.5) states: As of Linux 4.4, the RPi kernels support the dynamic loading of overlays and parameters. Compatible kernels manage a stack of overlays that are applied on top of the base DTB. Changes are immediately reflected in /proc/device-tree and can cause modules to be loaded and platform devices to be created and ...


2

Per this Pi Foundation forum thread There will be no registry maintained for ID data. You are free to use whatever data you want in the vendor fields of the "vendor info" EEPROM atom (0x0001), but of course the UUID must be unique and properly formatted. Further details can be found in the design guide and the ID EEPROM data format spec, and the ...


2

The HAT spec basically calls for the EEPROM to be an I2C device slaved on address 0x50 (which is more-or-less an industry default). At boot time, the device tree layout and other stuff is read from that EEPROM, and the recommendation is to leave those pins alone. So there shouldn't be any problem accessing that EEPROM anytime you like (it's just a slave ...


2

The 3 has the same form factor as the 2/0/+ models, with the same 40 pin GPIO header, so yes. The buses involved will work the same way, hence so should the software.


2

You can play from either, as long as the kernel modules for both are loaded. The method for doing this is as follows : Stop lxpanel Unload the audio drivers (rmmod or modprobe -r) Load the audio drivers (modprobe) Start lxpanel The reason why you have to disable or stop/start lxpanel is that the volume plugin hangs the system when you try to unload audio ...


2

The I2C bus is implemented on pins 3 and 5 of the Pi (GPIO 2 and 3, see https://pinout.xyz/). You need to concentrate your efforts to make sure there are no shorts or similar defects on those pins. You could try the following test to see if the base I2C GPIO appear to be functioning. Enter the following commands in a terminal window (prompt $ assumed). ...


2

For anyone finding this on Google, here's the answer based on what @jaromanda and @dougie commented... The holes I coloured green are connected to the corresponding holes in the GPIO connector, so to connect to a GPIO pin, you just have to solder to the corresponding green hole. Note: one of the holes on the GPIO connector has a square outline, which ...


2

OR, you could use just a PoE Splitter which is half the price of a PoE Hat and avoids the issue of trying to stack multiple hats on top of each other. I paid £9.90 for the GB version of the PoE Splitter. The same company sells a 10/100 speed version, so check you are buying the GB version before clicking "buy"-


2

I suspect the HAT you're looking for is the PiJack HAT, although intended for the Pi Zero I see no reason why it couldn't be persuaded to work on your Pi 3. Otherwise you may need to roll-your-own HAT using something like an ENC28J60 to give you an ethernet port over SPI and then implement some drivers. Finally, a controversial suggestion: have you thought ...


2

See https://www.youtube.com/watch?v=rrRg1guojQE This shows (my) pigpio library being used to control a variety of devices. A Raspberry Pi controlling a variety of motors and sensors. The pan-tilt head is moved by a pair of servos. The head holds a sonar ranger and an ADXL345 3-axis accelerometer. The servos control pins are connected directly ...


2

Pi HAT Waveform Generator for Raspberry Pi 3B+ 300 kHz sine waves at about 8 samples per waveform Sampling rate required is around 2.5 MSps. Have you considered the function generator modules? They are as small as 2.5cm x 5cm, so can piggybacked on to Rpi. References AliExpress AD9850 DDS Signal Generator Module 0-40MHz 2 Sine Wave and 2 Square ...


2

The USB port is NOT available on the 40-ping connector! If a USB serial is enought for debugging then you could add a USB-Serial chip like CP210x, CH340/CH341 or equal to the UART RX/TX pins, then you will get a USB serial on your HAT.


2

Answer Remark: Just a quick and dirty answer. Perhaps more details later. Warning: no guarantee no nothing won't meltdown or blow up. I skimmed the datasheets and quickly concluded that there is 80% chance OK, for the following reasons: (1) Touch display is SPI, and relay is I2C, (2) I2C relay has well documented instructions to change ...


2

I wanted to know if it's possible to stack the hats Depends on the HAT - the Sense HAT exposes pins BUT putting another HAT on top would make it unusable. Some have stackable headers but not all. The Pi exposes GPIO 0-27, of which 0,1 are reserved - leaving 26. The Sense HAT uses some of the pins https://pinout.xyz/pinout/sense_hat so not all are ...


2

That is a servo and is controlled as other hobby servos. I.e. 50 Hz pulses in the range 1000 to 2000 microseconds long. The code will look the same.


2

I wasn't able to get the ports each HAT will be using for the ReSpeaker 4-Mic Array and the 12-Bit/8-Channel ADC HAT. But I'm pretty sure you won't be able to do so because of an overlap in the pins the HATs will be using.


1

I ended up using the 4 x AA battery holder option. Power goes in to the VIN connector, ground to the GND. Unfortunately these don't have terminal blocks (everything else does), so to create a truly no-solder option I used the very-hacky technique of wedging toothpick tips into the solder holes suggested on another forum. If anyone's interested in using the ...


1

You can’t make an official HAT because it would miss the configuration pins. The pin mapping on 26 pin headers differs. Only you can decide if this is important. I think only 3 pins differ. See Which GPIO pins on previous modela are equivalent to those on the B+ model? The mechanical position also differs.


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