Member postings for john swift 1

Hi Graham

from what I can see all manufactures of the LCD / keypad shields don't use the same values of resistors for the Keypad

look here at the post from sillyoldDuffer 9/12/2016 for alternative values for reading the key pressed : -

http://www.model-engineer.co.uk/forums/postings.asp?th=122792&p=4

John

PS

you cannot use PWM on all boards terminal  D10 to control the brightness of the LCD's backlight

some boards like the one from maplin you can use PWM as they   have a resistor between the terminal D10 and the base of the transistor that controls the back light

others don't have the resistor and the arduino will be damaged if the atmel chip is programmed to pull the D10 terminal up to +5V

PPS

in my album you will find the circuit of the linksprite / maplin board with details of the all  important resistor needed if you use PWM  backlight control

Edited By john swift 1 on 10/01/2017 18:53:25

A Halon 1211

I could do with false paperwork to get it re charged since the inmates have taken over the asylum and stopped you and I from buying Halon extinguishers

John

Brian

+1 from me

they have to be different just look at their wacky SECAM tv system

they would not transmit programs using the American NTSC (never twice the same colour ) or

heaven forbid PAL as used in Germany & the UK.

Ironically the tv stations had to use PAL so could use a PAL vision mixer to mix between the various video sources.

the stations output being converted to SECAM for transmission

Edited By john swift 1 on 05/01/2017 23:25:59

I've not yet decided if it's one of those things you buy and find its not as useful as you first thought but how about this tape measure - £2.99 from amazon

Edited By john swift 1 on 05/01/2017 21:56:59

part 2

I have just had a quick look at changing the code to use as the enable pin 4

as it is now it disables the motor at the wrong time

when I changed the enable setup it produced an error -

at 01:05 - its probably me

I'll have to see it as an opportunity to learn more about programming the arduino

John

'Hi Carl

Your the first to comment about my avatar televisor and Nipkow disc

( Nipkow disc patented in 1884 by Paul Gottlieb Nipkow )

Today I proved , just using the step and direction signals to control a stepper motor driver and motor every thing works as expected

I see no point connecting the drivers -enable to the arduino digital output pin 11 when its always high and enables the drive

the driver enable is a negative logic input - no input = drive enabled !!

John

Hi Carl

only having the Arduino and LCD shield a day your rotary table control is the 3rd program I have tried

and it works although I need to find the step and direction outputs

( the first being the blink & fade examples that come withe the arduino ! )

some my web searches for the arduino highlighted the issue with some LCD shields if you attempt to use PWM brightness control

(while its not an issue with your project now but it can be when an astromomer adapts it to control a telescope drive )

with a box of general purpose matrix boards

it makes sense to me to use a mixture of matrix boards I have and arduino shields

I need to look closer for the step & direction outputs are they output pins D0 & D1 ?

are the outputs open collector and need pullup resistors to test without connection to a stepper driver ?

John

now I have an Arduino uno clone and I picked up a LCD sheild yesterday

I can update the diagram for a PWM compatable LCD sheild and possible veroboard DIY sheild

I need to double check which arduino pins are used for the stepper driver

I thought digital outputs 0 & 1  are used for step & direction but I can't find the expected step pulses when I jog or run

note - on this sheild the 10K between pin D10 and the transistor base prevents damage to the Arduino

I have confirmed 3 out of the 4 UNO terminal line up with the 0.1" grid of veroboard / perf board

using the long pin Stackable Header Connector sold for the arduino

the offset of J2 (D8 to D13 , gnd & ref) is small enough to bend the pins to fit int the Arduino socket

John

Edited By john swift 1 on 13/12/2016 11:44:24

Hi

I don't have an arduino uno and LCD + switch sheild but

pre empting buying them to experiment with I have found conflicting notes about the LCD sheild

it seems that some boards you can only use D10 to switch the display LED backlight on & off

others you can use PWM to contol the brightness

this is what I have so far

John

PS

routine to read keys

int read_LCD_button()     // routine to read the LCD's buttons
{
  int key_in;
  key_in = analogRead(0);      // read ADC
  // average values for my board were: 0, 144, 324, 505, 742
  // add approx 100 to those values to set range
  if (key_in > 1000) return NO_KEY;    
  if (key_in < 50)   return RIGHT_KEY;  
  if (key_in < 250)  return UP_KEY;
  if (key_in < 450)  return DOWN_KEY;
  if (key_in < 650)  return LEFT_KEY;
  if (key_in < 850)  return SELECT_KEY;  
}

hope you can now check your keys

Edited By john swift 1 on 09/12/2016 16:48:53

Hi Zebethyal

reading your comment about non standard spacing that perpetuates the use of shields,

has me thinking about a DIY solution

I've no found all the information I need

Probably need to obtain an Arduino and a variety of connectors and a piece of veroboard (perf board) and have a go

this is just my initial thought :--

John

Hi Duncan

the Arduino Nano looks like a useful component to incorporate into DIY projects

now I'm spoilt for choice

John

Hi Duncan

I was thinking if I don't need the USB port , I can replace several 5V logic IC's with the Atmel chip + crystal and save the space taken by the Arduino uno board

I expect I can either use a Atmel in circuit programmer or Arduino uno board to program the Atmel chip

John

PS

the THB6064 driver can either be bought as a kit to assemble your self

http://www.massmind.org/Techref/io/stepper/THB6064/index.htm

or

ebay , amazon etc

first web search result -

http://www.ebay.com/itm/New-THB6064AH-JP-6445A-Single-Axis-Stepper-Motor-Driver-/121384856405

PPS

Atmel programmer for Arduino

http://www.ebay.co.uk/itm/USBASP-USBISP-ISP-Programmer-Cable-Adapter-KK2-0-KK2-1-Atmel-AVR-ATMega-ARDUINO-/131241223483?var=&hash=item1e8e96253b:m:my5ajIyIlNHKV-vZffc0xBg

Edited By john swift 1 on 05/12/2016 01:13:45

Hi Carl

after reading your project in MEW 249 I'm having a look at the arduino

it could be an alternative to hard wired logic in my own projects

now I see the Atmel chip with the Arduino boot loader is available from Farnell

http://uk.farnell.com/arduino-org/a000048/mcu-8bit-atmega-20mhz-dip-28/dp/1848694

with your project being based on a old design

the one change I would consider making is to replace the "TB6560" stepper driver with the later THB6064AH drivers that survive being run at their published limits unlike the TB6560

John

PS

I see you adapting Gary Liming's design no different to the likes of the British Radio Corporation (HMV, Ferguson ,Marconi, Fidelity) building radios and TV's based on Mullard's application design examples with minimal alteration

Edited By john swift 1 on 04/12/2016 20:19:22

Hi Dave

without the blue print or detailed photos to be able to reverse engineer your guitar

I can only guess the guitar is wired like this

with this fuzz box built in - circuit found on the net

John

No, but not un expected when you buy China Export

the fuse should be there to protect the mains flex since the 32A fuse/breaker for the ring main isn't going to protect it (or the plug and socket !)

John

Edited By john swift 1 on 27/11/2016 17:50:49

Hi Geoff

how about a razor made to re sharpen every morming

John

we need both photos of the guitar and detailed photos of the wiring from Dave Trafford

but it could of been the guitar from Every Day Electronics Nov 72

photo from advert

example wiring

          John

Edited By john swift 1 on 23/11/2016 13:50:09

any pictures of your solder joints available ?

provided the PCB tracks and component leads are free of any oxidisation and are not contaminated with the oils from your skin

any soldering iron equivelent to an Antex XS25 to a 50W Weller WTCP50 magnastat iron with a number "7" (700F) bit works with lead free or 60/40 solder

60/40 solder is the easiest to start with and should easily melt and flow as it comes into contact with the hot PCB track and component wires

John

just right clicked the photo in Johns folder and then save as

then used photostudio to rotate by 90

 didn't use print screen to  saved what was displayed on my screen I know thats not the same

John

 edit to correct spacing

Edited By john swift 1 on 07/10/2016 15:16:26

they say you learn something new every day

just watched part of a channel 4 program about icing sugar

and it showed a clip dusting bees with icing sugar to control varroa mites

the idea being as the bees cleaned each other the mites would lose their grip and fall off and land in the bottom of the hive

John

Edited By john swift 1 on 03/10/2016 22:06:21