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by techpaul
Thu Mar 20, 2014 4:53 pm
Forum: Beginners
Topic: Using incoming UART data for processing in other application
Replies: 3
Views: 838

Re: Using incoming UART data for processing in other applica

As you have been told in previous threads, work out your data flows

40 kHz data at 8 bits needs at least a 400 kbps UART link. as each byte requires 10 bits for transmission

So check your PIC and the Pi can do at least 400 kbps on UART and the software at each end can keep up.
by techpaul
Thu Mar 20, 2014 2:15 pm
Forum: HATs and other add-ons
Topic: infrared beam
Replies: 3
Views: 1721

Re: infrared beam

First work out the physics requirements how big you hole is How far in does an object have to go to be detected What is smallest and largest object to be detected Be sure any method of detection covers the opening area and more How quickly do you want the sensor to respond 'immediately' is not an op...
by techpaul
Thu Mar 20, 2014 1:33 pm
Forum: General discussion
Topic: Things I've Learned
Replies: 31
Views: 3612

Re: Things I've Learned

Ravenous wrote:(42) Most attempts to start a positive thread end up attracting whining posts.

(Yes, including this one.)
So you going to cite Godwins Law :D
by techpaul
Thu Mar 20, 2014 10:43 am
Forum: Other projects
Topic: RS-232 Console server
Replies: 3
Views: 1011

Re: RS-232 Console server

Depends what you want to do as in miss data or buffer data for each port You could use relays or just straight analog muxs or just TTL multiplexers or even a manually operated 8 way 9 way D switch. Be aware you will probably have to throw away characters in these methods as at time of switching the ...
by techpaul
Thu Mar 20, 2014 10:14 am
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

You will need to work out how to create a bi-directional SDA which the software does not do as during ACK time you must change output to input. You sould try I2C with MAXIMUM speed of 600 or even 500 (which may be reported as 0k as the report does not do fractions of kHz. Running fatsre than 600Hz o...
by techpaul
Thu Mar 20, 2014 10:02 am
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

Double checked the pins, they are correct. http://pira.cz/rds/mrds192.pdf - Figure 3.1 shows pull up resistors, but then at the bottom of that page says it needs pull-up resistors. Since I'm now coming straight off the pins, I might have missed a point of your recommendation for needing pull up res...
by techpaul
Thu Mar 20, 2014 1:02 am
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

Hopefully not from the USB to serial cable or USB port I bent up pins 6 and 7, ran wire to P5 pins 3 and 4 and connected a ground wire. That is between the chip direct to the Pi. No serial to usb cable at all. Ensure you have powered up the device, and that SCL and SDA are wired the correct way rou...
by techpaul
Thu Mar 20, 2014 12:22 am
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

Hopefully not from the USB to serial cable or USB port
by techpaul
Wed Mar 19, 2014 11:20 pm
Forum: Beginners
Topic: can't open port 80 on BThomehub4
Replies: 9
Views: 1894

Re: can't open port 80 on BThomehub4

By open you mean port forward ?? Port 80 is usually reserved for the internal setup page of the router so it's highly likely you cannot use it. Richard S. Hopefully not from the public side on local side yes. Broadband side is how to let people to lock you out of your own router. Most routers block...
by techpaul
Tue Mar 18, 2014 7:09 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Some kind of magic with I2C and KS103 (distance sensor)
Replies: 2
Views: 1020

Re: Some kind of magic with I2C and KS103 (distance sensor)

The thing to understand no matter what any manufacturer says. I2C addresses are 7 bits long The eight bit transmitted is a control bit, not an address bit. Using I2C driver or (python smbus) you give it the address, the function calls for read or write determine how to set the control bit. You do no...
by techpaul
Tue Mar 18, 2014 1:50 am
Forum: General discussion
Topic: Things I've Learned
Replies: 31
Views: 3612

Re: Things I've Learned

20. I have this pille of random undocumented componets if I put them in the vicinity of the Pi it should work there must be something wrong with this Pi not accepting my 240V input to GPIO

19 Why cant I run Windows 8 on Pi
by techpaul
Tue Mar 18, 2014 1:46 am
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

Personally I would not connect this poorly documented and possibly not standards compliant device to anything. The easiest way to connect this device to a Pi is pull RDS chip out of module, bend up SCL and SDA pins, solder wires to pins, reinsert IC in socket, connect wires to Pi along with a GND co...
by techpaul
Tue Mar 18, 2014 12:01 am
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

Model number and details of EDM radio module would help.
by techpaul
Mon Mar 17, 2014 11:59 pm
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

With 680R as series resistance on SCL and SDA I am amazed antything is seen with 5V1 zeners in there I am amazed anything works. You appear to be connecting5V I2C to 3V3 Pi GPIO (I2C) Can you try with all other devices disconnected the 'UU' is an error condition on i2cdetect, before your device. Wha...
by techpaul
Mon Mar 17, 2014 11:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI
Replies: 5
Views: 1329

Re: SPI

The only thing I have seen from teh datasheets is that the Nordic chip appears to have a maximum clock rate of 10Mhz but could be as low as a max of 4MHz depending on capacitive loading and pull up values. See datasheet Tables 18 to 23 on pages 49 - 50. Also the MCP3008 (page 4 of datasheet Timing P...
by techpaul
Mon Mar 17, 2014 1:44 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP23017 reset itself
Replies: 15
Views: 6225

Re: MCP23017 reset itself

FLYFISH TECHNOLOGIES wrote:Hi,
techpaul wrote:SCL and clock as another pair.
Lapsus ? SCL and GND..
Yes one of those days
by techpaul
Mon Mar 17, 2014 1:38 pm
Forum: Troubleshooting
Topic: GPIO 3.3v pin overheat
Replies: 5
Views: 1132

Re: GPIO 3.3v pin overheat

Sounds like you have connected to 5V not 3V3 or miss wired a GND Diagram/photo of your ACTUAL configuration would help. Not that it would make much difference what happens if you cut SJ2, SJ3, SJ4 ? This disables pull ups on the SDA, SCL and IRQ line, which may have meant if you wired to 5V instead ...
by techpaul
Mon Mar 17, 2014 1:26 pm
Forum: Automation, sensing and robotics
Topic: MCP3008 ADC Project Question
Replies: 9
Views: 1505

Re: MCP3008 ADC Project Question

He needs to see at most a block diagram of the chip. Plus copy of dataheet in the Appendix. By the way this is sufficient for many long life support projects in medical, aerospace and miltary applications (not all but most). Anyway if you have any transistors/FETs or Regulators or op-amps on the boa...
by techpaul
Mon Mar 17, 2014 1:20 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI
Replies: 5
Views: 1329

Re: SPI

A circuit diagram of how you have connected up the SPI interface between SPI and devices would help. As has already been said just turning off power to a device will not help if the SPI lines are still connected they need to be isolated as well, otherwise you will power the device throiugh its I/O a...
by techpaul
Mon Mar 17, 2014 1:12 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP23017 reset itself
Replies: 15
Views: 6225

Re: MCP23017 reset itself

Length of wiring Pi to MCP23017s, insufficient power decoupling, insufficient screening. Cables runs may be picking up noise from something else entirely. On Grounding Pi, MCP23017, and LED input of opto iosolators must be on same ground. I would if possible power the ralays totally separately (even...
by techpaul
Mon Mar 17, 2014 1:02 pm
Forum: Python
Topic: Bit banging to read/write RDS info
Replies: 141
Views: 17192

Re: Bit banging to read/write RDS info

I have a USB to serial cable I used that has 4k7 resistors in it (thought I posted it easier today - guess i didn't) and I have that connected to +5, gnd , scl and sda pins. I'll repost when I get back from the office what that cable looks like. I thought it was essentially pull-up resistors but it...
by techpaul
Sun Mar 16, 2014 9:51 pm
Forum: Troubleshooting
Topic: Free wheeling clock versus real time
Replies: 10
Views: 2249

Re: Free wheeling clock versus real time

The issue had more to do with me trying to pulse a gpio once each (NTP) second boundary - and wondering why it happened every 1,000,025 Pi ticks. Maybe your time pulse is being started every 1,000,000 ticks (+/- tolerance) and 25 ticks to toggle GPIO and schedule again via instructions. Random thou...
by techpaul
Sun Mar 16, 2014 2:08 pm
Forum: Python
Topic: Binary Counter without using shift register such as 74HC595
Replies: 4
Views: 2261

Re: Binary Counter without using shift register such as 74HC

Untested but should work code to try using binary operations which is less overhead than a modulus operation (%) simple ands and shifts are easier to do. Also only calls one function, whilst also only setting up GPIO as outputs ONCE #!/usr/bin/env python3 #Date: 12th, March 2014 # modified and untes...
by techpaul
Sun Mar 16, 2014 1:46 pm
Forum: C/C++
Topic: wiringPi build error
Replies: 8
Views: 3227

Re: wiringPi build error

when i try : ./build -> permission denied! Then I would check you actually followed the steps on https://projects.drogon.net/raspberry-pi/wiringpi/download-and-install/ correctly or downloaded the correct version or have a corrupted file. Try to ensure you have latest version if that fails try the ...
by techpaul
Sun Mar 16, 2014 1:35 pm
Forum: C/C++
Topic: wiringPi build error
Replies: 8
Views: 3227

Re: wiringPi build error

nitram0598 wrote:How without sudo bash??
Follow instructions on Wiringpi site for installation

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