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by brekee12
Sun Jun 03, 2018 4:50 am
Forum: Automation, sensing and robotics
Topic: piscope
Replies: 7
Views: 1012

Re: piscope

Hi Joan, I am dealing with MSP430 and CC2500 radio. All the IOs are used of the uC, so I have to write a bitbang SPI on uC. Something goes wrong. The radio works on the Raspberry SPI, but not on the MSP430. I quickly connect Raspberry GPIO 18-21 to the bitbang SPI and installed PiScope. At first run...
by brekee12
Mon Jan 23, 2017 9:10 am
Forum: Python
Topic: How to send 16bit via spidev?
Replies: 5
Views: 910

Re: How to send 16bit via spidev?

Try pigpio library with second spi device not with standard spidev. Probably your AD7490 does not accept CS handling during the 16 bit communication. Between the two words it raises momentarly that can be the problem. Unfortunatelly, it is a long time ago I made C programming of this second spi but ...
by brekee12
Tue Jan 17, 2017 12:48 pm
Forum: Automation, sensing and robotics
Topic: Power Meter 3AC 50Hz with 3 current and 3 voltage sensors
Replies: 3
Views: 887

Re: Power Meter 3AC 50Hz with 3 current and 3 voltage sensor

To measure three phase it is very complicated. Not only question of ADC but isolation is crucial point of your project. The best way to study electronic power meter IC-s.
by brekee12
Tue Jan 17, 2017 12:41 pm
Forum: Troubleshooting
Topic: Power problems with B+ 2 and a 5v 9amp Power Supply
Replies: 5
Views: 944

Re: Power problems with B+ 2 and a 5v 9amp Power Supply

The problem is probably with the power supply. If (and probably so) switching supply, drops momentarly it's voltage because of connecting Wifi (consumes a lot power especially at connection time). What kind of supply do you have (230AC/5V, 12V/5V, ...)?
by brekee12
Thu Dec 15, 2016 3:08 pm
Forum: Beginners
Topic: How to know which one DS18B20 has failed
Replies: 7
Views: 1087

Re: How to know which one DS18B20 has failed

sensor_tfile[1] ="/sys/bus/w1/devices/10-000802a08713/w1_slave" in this title 000802a08713 is a uniqe serial number. Before you put your system up and running sign your sensors on the hardware, so it is easy to identify which one went wrong. It is a little extrawork at the beggining signing one-by-o...
by brekee12
Wed Dec 14, 2016 1:18 pm
Forum: Beginners
Topic: 5V, 240ma Fan
Replies: 6
Views: 1226

Re: 5V, 240ma Fan

Simple use a TIP120 type transistor in open collector mode. This can drive even a 1A fun from 5V supply, loading raspberry output with a mA. 5V can be loaded with 240 mA only the power supply must support at least 2.5A-s to make sure raspberry gets enough power.
by brekee12
Tue Dec 13, 2016 2:41 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: i2c detection issue
Replies: 10
Views: 1528

Re: i2c detection issue

Raspberry I2C works on 3.3V. So, do not use 5 V supply, use 3.3V. If it is directed from the board supplier you need level converter or multiplexer with 5V tolerant SDA and SCK. Make sure nothing gets over 3.3V to the data and clock pin! Raspberry is not 5V tolerant!
by brekee12
Thu Dec 01, 2016 7:35 am
Forum: C/C++
Topic: 24lc1025 memory interfacing
Replies: 9
Views: 1230

Re: 24lc1025 memory interfacing

As I have a look at the datasheet there is a read and a write instruction randomly read and write memory address. Try to follow that in the datasheet end. Be careful if you have seen address 0x50 the device read instruction is address 0x51. This is the properties of the I2C bus. At the end of the da...
by brekee12
Wed Nov 30, 2016 1:37 pm
Forum: Automation, sensing and robotics
Topic: Use pi as voltage meter?
Replies: 13
Views: 2998

Re: Use pi as voltage meter?

Search the forum. There are many people solved that using PHP, webserver and so on..
by brekee12
Wed Nov 30, 2016 1:34 pm
Forum: C/C++
Topic: 24lc1025 memory interfacing
Replies: 9
Views: 1230

Re: 24lc1025 memory interfacing

In the first byte R/W must be setup properly (giving different address) of read and write because of the properties of the I2C bus. I think before you go further you should deeply study I2C bus specification and and the datasheet. Unfortunatelly I can not help you further because I did not use I2Cpr...
by brekee12
Wed Nov 30, 2016 4:54 am
Forum: Automation, sensing and robotics
Topic: Use pi as voltage meter?
Replies: 13
Views: 2998

Re: Use pi as voltage meter?

Yes, you can do measurements with ADS1115. High Voltage sensors need voltage dividers, but using some resistor solves the problem. I2C bus is ideal for low sampling rate converters, you can use as much as four AD on the bus and the wide supply range makes it easy to interface for RPi applications. S...
by brekee12
Tue Nov 29, 2016 2:39 pm
Forum: C/C++
Topic: 24lc1025 memory interfacing
Replies: 9
Views: 1230

Re: 24lc1025 memory interfacing

I never used i2ctools to program memories, however there are some information in the manual pages and the readme files. You can also googling.
by brekee12
Tue Nov 29, 2016 9:57 am
Forum: C/C++
Topic: 24lc1025 memory interfacing
Replies: 9
Views: 1230

Re: 24lc1025 memory interfacing

Try to use pull-up resistor. In some cases I had the problem with not enough strong pull up.
by brekee12
Tue Nov 29, 2016 8:09 am
Forum: C/C++
Topic: 24lc1025 memory interfacing
Replies: 9
Views: 1230

Re: 24lc1025 memory interfacing

First of all, which I2C port are you using. There are two 0 and 1. 0 has no pull-up resistors! 1 has the resistors but it makes sense to use two other 3k3 pull up. Check whether your I2C bus enabled in raspi-config and you are added to i2c group in /etc/group. If all this are OK you should see your ...
by brekee12
Sat Nov 26, 2016 5:45 pm
Forum: Automation, sensing and robotics
Topic: Use pi as voltage meter?
Replies: 13
Views: 2998

Re: Use pi as voltage meter?

First off all you need a resistor divider. It has to have two resistor connected in series. The values depend on what current affordable from the 30-50V. Have an example: 100uA is supported so the two resistor together should be 50V/0,0001A= 500kOhm. I do not remember exactly ADS1115 input range but...
by brekee12
Fri Nov 25, 2016 6:54 am
Forum: Beginners
Topic: Power supply
Replies: 18
Views: 2367

Re: Power supply

Easiest way is that Raspberry powered continuously from a wall adapter. It cost almost nothing, but immediatelly ready to use after powering the TV. It also best for the Pi, not switching on and off all the time.
by brekee12
Fri Nov 18, 2016 7:19 am
Forum: Gaming
Topic: USB Soldering Help is Needed
Replies: 6
Views: 1346

Re: USB Soldering Help is Needed

Sorry, but I don't know the extension. However, If you could solve your problem without unreversable (soldering) changes of the board would be preferable. It is always good to have a chance to use things in the original state. It is like a rule of thumb.
by brekee12
Thu Nov 17, 2016 4:35 am
Forum: Gaming
Topic: USB Soldering Help is Needed
Replies: 6
Views: 1346

Re: USB Soldering Help is Needed

OK, I have got it. In the USB power is only 500mA-s power supplied. With the extended USB power (set in the config.txt) 1.2 Amps the maximum you can draw. 1 sqare miliimeter wire can conduct 6A as rule of thumb, so 1.2/6=0,2 sqare millimeter which is (if I remember well ) AWG 24 with 0,5mm wire diam...
by brekee12
Wed Nov 16, 2016 4:56 pm
Forum: Gaming
Topic: USB Soldering Help is Needed
Replies: 6
Views: 1346

Re: USB Soldering Help is Needed

Why do not you use standard USB cable. A standard USB-A u-USB cable fits to your requironments, only the power source must be USB A female.
by brekee12
Tue Nov 08, 2016 2:16 am
Forum: General discussion
Topic: Seek Hardware: 120v AC Switch That Defaults to "On"
Replies: 4
Views: 673

Re: Seek Hardware: 120v AC Switch That Defaults to "On"

Sorry for my bad english it is not clear why should you switch on and off your board? My board is running a clock program. I am welcomed at the morning and say good night at the evening (espeak). The board is powered continuously for weeks and even development period just minimal numbers restarted i...
by brekee12
Mon Nov 07, 2016 5:51 pm
Forum: Troubleshooting
Topic: Espeak error with USB Del Soundbar (but Youtube sound works)
Replies: 5
Views: 1054

Re: Espeak error with USB Del Soundbar (but Youtube sound wo

It is alsa problem. Normally gives some error messages (does not find jack server and some alsa messages), because alsa defaults to the jack connector, there maybe you got the voice, but clearly alsa not configured correctly. Sorry I am on RPi 1B.
by brekee12
Mon Nov 07, 2016 8:33 am
Forum: Troubleshooting
Topic: Espeak error with USB Del Soundbar (but Youtube sound works)
Replies: 5
Views: 1054

Re: Espeak error with USB Del Soundbar (but Youtube sound wo

The error messages are correct. Would you share the command you start espeak. The issue come up mainly by incorrect setup of the alsa and espeak can not use it right way.
by brekee12
Fri Nov 04, 2016 1:29 pm
Forum: Beginners
Topic: white LED strip with transistor
Replies: 14
Views: 3699

Re: white LED strip with transistor

MOSFET is like a capacitor, which is charged and discharged. Higher the frequency, more driving current needed which heets Raspberry's power output stage. Heatsink can help a little, but because your RPi is running on high temperature: - shorten the lifetime - no possibility to connect other device ...
by brekee12
Fri Nov 04, 2016 7:00 am
Forum: Beginners
Topic: white LED strip with transistor
Replies: 14
Views: 3699

Re: white LED strip with transistor

I am not familiar with python, but if you switched the transistor too often (high frequency) RPi outputs more current to gate than it should. That is why it comes hot. You should decrease the frequency to some tenth of Hz with wide range of PWM or you must use MOSFET driver IC.
by brekee12
Thu Nov 03, 2016 12:15 pm
Forum: C/C++
Topic: Turning LED on/off with keyboard button
Replies: 3
Views: 1684

Re: Turning LED on/off with keyboard button

Install PIGPIO library and it becomes so easy to write your program you does not need help. It does not matter you are in CLI, C or python just a couple of line.

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