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by chipace
Fri Nov 08, 2019 4:26 am
Forum: Advanced users
Topic: Raspberry Pi3 I2C baud rate setting
Replies: 15
Views: 5312

Re: Raspberry Pi3 I2C baud rate setting

Code: Select all

modprobe -r i2c_bcm2708
modprobe i2c_bcm2708 baudrate=1200000
This worked on my previous rpi. No need to reboot.
by chipace
Tue Nov 05, 2019 12:01 am
Forum: General discussion
Topic: MCP4725 DAC with LCD issues
Replies: 40
Views: 1012

Re: MCP4725 DAC with LCD issues

As Joan has already pointed out the LCD connected as shown in the linked document is not an I2c device so it will not show up as an I2c device. The LCD is being driver directly from the gpio using 4 data pins and 2 control pins . Sorry about that. My 20x4 LCD is an i2c device... I was assuming ever...
by chipace
Mon Nov 04, 2019 11:49 pm
Forum: Beginners
Topic: Raspberry Pi INA219 Tutorial problem
Replies: 15
Views: 287

Re: Raspberry Pi INA219 Tutorial problem

Are you able to see the i2c device address when you run the following command?

Code: Select all

i2cdetect -y 1
I can't see where you are specifying your i2c device address in your python script.
I assume your A0 and A1 pins are tied to GND so that you have a device address of 0x40.
by chipace
Mon Nov 04, 2019 9:21 pm
Forum: General discussion
Topic: MCP4725 DAC with LCD issues
Replies: 40
Views: 1012

Re: MCP4725 DAC with LCD issues

The problem I tnink lies with the modules that I have had trouble installing. I will start the whole process again with a fresh install of Raspbian, so that all superfluous stuff is ersaed. I would try the LCD by itself on the i2c bus. When you removed power to the MCP4725 with both devices on the ...
by chipace
Mon Nov 04, 2019 4:22 am
Forum: General discussion
Topic: MCP4725 DAC with LCD issues
Replies: 40
Views: 1012

Re: MCP4725 DAC with LCD issues

I have used both of those on my RPi. I am not sure which stage you are at but here is my approach. (1) Ensure that the I2C bus is enabled (Use the Raspberry Pi Configuration GUI or edit /boot/config.txt). Reboot. (2) Connect first device. Connect power and ground to the MCP4725. Connect the i2c bus ...
by chipace
Wed Oct 02, 2019 7:10 pm
Forum: Advanced users
Topic: Looking for help with J2 on the Pi 4
Replies: 1
Views: 252

Re: Looking for help with J2 on the Pi 4

I soldered a push-button on my RPi4 between GLOBAL_EN and GND. It can be used as a hard reset or wake after shutdown. I needed to use it once as a hard reset... the board locked up and was completely unresponsive, but the wake function I use everyday. If the usb-c power supply is always left attache...
by chipace
Tue Oct 01, 2019 11:12 pm
Forum: Advanced users
Topic: MS5540 water depth sensor
Replies: 2
Views: 241

Re: MS5540 water depth sensor

Looks like a SPI device without a chip select. Here is some sample code where I set the spi channel and clock frequency in Python. I use spidev to talk to the part. You will need to drive the MCLK at 32kHz if your board does not have an oscillator. Hope this helps #!/usr/bin/python import spidev # =...
by chipace
Wed Sep 18, 2019 6:09 am
Forum: Advanced users
Topic: pyusb traffic is different on RPi4
Replies: 1
Views: 136

pyusb traffic is different on RPi4

I am looking at wireshark logs between my oscilloscope and RPi4 (connected with USB 2.0). If I use the same SD card in my RPi3 and RPi2 I have no issues with my pyvisa/pyusb script. When I insert it into my RPi4, I am seeing differences in the usb traffic. Is there a way to identify from the wiresha...
by chipace
Thu Sep 12, 2019 7:06 am
Forum: General discussion
Topic: RPi4 pyusb and libusb1 detach kernel driver
Replies: 2
Views: 143

Re: RPi4 pyusb and libusb1 detach kernel driver

I'm using pyvisa and pyusb to download screen captures from my oscilloscope. import visa import datetime import time import re import csv from math import floor, log10 class rigol_ds1054z: # Constructor def __init__(self, debug=False): resources = visa.ResourceManager('@py') # insert your device her...
by chipace
Wed Sep 11, 2019 2:52 am
Forum: General discussion
Topic: RPi4 pyusb and libusb1 detach kernel driver
Replies: 2
Views: 143

RPi4 pyusb and libusb1 detach kernel driver

I am trying to get my RPi4 to work just like my RPi3 and RPi2 when using pyusb and libusb1. In looking at the log files it appears that RPi3 and RPi2 detach the kernel driver, while the RPi4 does not when doing communication on a specific USB port. I am using the same SD card and inserting it into t...
by chipace
Tue Sep 03, 2019 5:14 pm
Forum: General discussion
Topic: RPi4b USB 2.0 differences with previous RPi?
Replies: 3
Views: 327

Re: RPi4b USB 2.0 differences with previous RPi?

The Pi 4B uses a completely different USB controller to all other models of Pi. The type A ports are all driver by a VLI chip - the VL805. The original USB 2.0 controller used on previous models of Pi is present on the type C connector that is normally used to power the board. I don't know whether ...
by chipace
Tue Sep 03, 2019 1:31 am
Forum: General discussion
Topic: RPi4b USB 2.0 differences with previous RPi?
Replies: 3
Views: 327

RPi4b USB 2.0 differences with previous RPi?

Has anyone seen any usb 2.0 differences (compared to previous RPi) with the RPi4b? I am having problems with saving Kilobytes of data from my oscilloscope using pyvisa. Small queries work identical to previous RPi, but whenever I try to save screenshots, waveform csv data, or scope configuration I o...
by chipace
Fri Aug 30, 2019 6:52 pm
Forum: General discussion
Topic: Turn Off System Power Using GPIO Pin
Replies: 4
Views: 614

Re: Turn Off System Power Using GPIO Pin

emma1997 wrote:
Thu Aug 29, 2019 5:25 pm
Ran off same set of AA cells for almost 3 years now.
Sounds like you made an Amazon Dash button using a RPi0. Amazon used boost circuit to get that down to a single AAA.
by chipace
Wed Aug 28, 2019 5:49 pm
Forum: General discussion
Topic: Is it possible to measure the power consumption using raspberry pi? If yes then how?
Replies: 16
Views: 756

Re: Is it possible to measure the power consumption using raspberry pi? If yes then how?

Please, please, please don't use an INA219. Use the INA260. INA260 has a 2 milliOhm sense resistor integrated in the package and requires absolutely no calibration. It is possible to get much smaller LSBs using a custom sense resistor with the INA219, but you have to do a serious calibration routine...
by chipace
Sun Aug 25, 2019 6:03 pm
Forum: Python
Topic: RPi4b pyvisa is too fast
Replies: 1
Views: 130

RPi4b pyvisa is too fast

I just solved a problem I had with saving my oscilloscope's settings and screen captures using pyvisa. It turns out I needed to add some delay after I sent the SCPI command (over pyvisa) before I run read_raw(). My RPi3b+ does not need any delay, as it is just slow enough that the scope can be ready...
by chipace
Wed Aug 21, 2019 11:32 pm
Forum: General discussion
Topic: Uses for Raspberry Pi Zero/Zero W?
Replies: 81
Views: 3573

Re: Uses for Raspberry Pi Zero/Zero W?

For the price, its hard to resist adding one to any order I make, just to have spares to tinker with. I have 10 or so Zero W's kicking around here now. Do you also have 10 micro SD cards, 10 wall warts and 10 usb cables? Possibly 10 micro HDMI adapters and 10 OTG adapters too? I have enough micro S...
by chipace
Wed Aug 21, 2019 10:56 pm
Forum: General discussion
Topic: Uses for Raspberry Pi Zero/Zero W?
Replies: 81
Views: 3573

Re: Uses for Raspberry Pi Zero/Zero W?

alphanumeric wrote:
Wed Aug 21, 2019 8:10 pm
For the price, its hard to resist adding one to any order I make, just to have spares to tinker with. I have 10 or so Zero W's kicking around here now.
Do you also have 10 micro SD cards, 10 wall warts and 10 usb cables? Possibly 10 micro HDMI adapters and 10 OTG adapters too?
by chipace
Wed Aug 21, 2019 6:33 pm
Forum: General discussion
Topic: Uses for Raspberry Pi Zero/Zero W?
Replies: 81
Views: 3573

Re: Uses for Raspberry Pi Zero/Zero W?

I used one in a solar powered weather station. If it is not battery powered, a RPi2 or RPi3 will be fine. I always buy the latest RPi, so I really don't need extra low-cost RPis available for projects. I probably will not buy another Zero or recommend anyone to buy one, unless it is specifically run...
by chipace
Mon Aug 19, 2019 8:20 pm
Forum: General discussion
Topic: rpi-bootloader updates for Aug 19?
Replies: 15
Views: 1224

Re: rpi-bootloader updates for Aug 19?

https://github.com/raspberrypi/firmware/commits/master

Most of the changes are to binary files, so the comments are the only way to know of a specific change.
by chipace
Mon Aug 19, 2019 7:16 pm
Forum: General discussion
Topic: rpi-bootloader updates for Aug 19?
Replies: 15
Views: 1224

rpi-bootloader updates for Aug 19?

I saw that a new kernel and new rpi-bootloader was recently made available. Is there a blog page that lists new features which have recently been enabled? I am wondering if usb boot has been enabled for RPi4b.
by chipace
Tue Aug 06, 2019 9:23 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 22807

Re: Why moving to 64bit?

jamesh wrote:
Tue Aug 06, 2019 8:51 pm
We do have a HW roadmap, and on the whole we need software to run on that hardware, which drives the SW side
Would a 64bit Zero be in the roadmap? If there was, would that help the transition to a 64bit Raspbian?
by chipace
Tue Aug 06, 2019 7:12 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 22807

Re: Why moving to 64bit?

From a historical perspective, I believe Microsoft waited many years after x86-64 hardware was in circulation before it offered a 64bit OS. Maybe we could have a kickstarter to get the Zero hardware upgraded to an a53 core? Put it on a newer process and get even lower current consumption. When the Z...
by chipace
Sat Aug 03, 2019 9:25 pm
Forum: General discussion
Topic: Pi cluster for kubernetes
Replies: 10
Views: 771

Re: Pi cluster for kubernetes

You might want to wait for RPi4b to get PXE boot before building the cluster. No reason to have multiple sd cards... you want to set it up such that it could scale to 16 nodes, right? One master node to rule them all!
by chipace
Sat Aug 03, 2019 3:40 am
Forum: General discussion
Topic: video file playback orientation
Replies: 6
Views: 349

Re: video file playback orientation

Does VLC on your x86 box rotate it correctly? If not then it sounds like a generic VLC bug rather than anything Pi specific. Rotation is normally represented in the composition matrix of the MP4 file. (eg https://gitlab.com/SaberMod/pa-android-frameworks-base/blob/987ab4833ecbafbdf750eb1b04e4369343...
by chipace
Sat Aug 03, 2019 3:16 am
Forum: General discussion
Topic: Adafruit has 1GB RPi4 in stock
Replies: 1
Views: 111

Re: Adafruit has 1GB RPi4 in stock

Now just the 2GB versions are left.

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