Arduino tehNiq

Sunday, July 10, 2022

X9C103 digital potentiometer with EEPROM stored initial value

I received few X9C103 digital potentiometer modules with 10kΩ and I need to prepare it for tests:

I used this schematic:

where in A0 is voltage fron wiper of potentiometer (as a resistive divider for 5V power supply) and also I read 5V voltage in A0 (to check if is 1023).

In the previous tests with a remote contributor X9C103 potentiometer not store value in NVM, so I used an oscilloscope to saw the signals... the signals are ok, but chip not store the value in NVM (non-volatile memory):

so I used EEPROM memory from Arduino Nano board (ATmega328P chip).

Last sketch is pot_X9C103_1_1.ino. and in this sketch it used LapX9C10X library (also X9C103 chip "not want" to store the value using writeNVM() command from this library).

I upload the X9C103 digital potentiometer with EEPROM stored initial value where you can see how sistem works:

Bibliography: article in romanian language - Teste cu potentiometrul digital X9C103 (10kΩ) !

Thursday, June 23, 2022

Railway Crossing Multi Track Two Way

This article is based on the article with same name and Railway Crossing Part 4: Putting it all Together article.

My tests included few models until at last version with sounds (warnings) and other count method for trains, but main structures are same:

- Railway_Crossing_1 (just added tip and free lights), sketch: us_barriers_rudysarduinoprojects_1b.ino

video: bariera automata pentru 2 linii (sine) cu monitorizare trenuri

video: Railway Crossing Multi Track Two Way (lights improvements)

- Railway_Crossing_2 (added sounds using Mike Osborn MKO tips),sketch: bell_and_button_servo_4

- Railway_Crossing_3 (added sounds and test different count methods: original with few updates or big changes)

with 3 sketches

- us_barriers_2b

- us_barriers_2x

video: bariere automate cu avertizari sonore (americane) pentru 2 sine

video: Railway Crossing with Warnings for Multi Track Two Way

- us_barriers_2y

and last improved sketch:

with this schematic (LCD1602 with i2c interface is not added)

For last sketch, I uploaded this videos:

- bariera automata cu lumini si sunete pentru cale ferata dubla

- Railway Crossing with lights and sounds for Multi Track Two Way

If no train between IR sensors, barriers (gates) are open:

but at least a train is between sensors, barriers (gates) are closed:

29.08.2022

I changed the sketch for remove sound after gate is open (us_barriers_2b_2)

as Jedidiah Sawyer wanted.

You can see video named Arduino Railway Crossing with sounds (video by Jedidiah Sawyer):

Last change of the sketch is to have also fading light as in 2nd Avenue Railroad Crossing, Clanton, AL

so, last sketch is us_barriers_2b_3

and a short video made by Jedidiah Sawyer:

31.08.2022

The variable for change the fade effects are:

and the fade for LED3 is

so, LED3 is off (brightness = 0), than after 200ms (variable time_to_stop) brightness increased at 1 (variable fadeAmount), than after 2 ms (variable fade_delay) brightness is 2, after more 2ms brightness is 4, etc, until brightness is 255 (maximum = 100%) .. is a pause (time_to_stop = 200ms) and after that brightness decrease with 1 at every 2ms until 0...

Leds for blink effect (LED1 and LED2) are same period as fadding leds (LED3and LED4):

..so, you can change the values as you want,...

Wednesday, May 18, 2022

How to define, store, test and control the turnouts (with servo) in DCC++Ex

As a beginner with model railroading I tested also DCC control using a custom locomotive.

My custom locomotive was make using just bogie from an old locomotive, adding DCC ready board and NEM652decoder.

DCC control was choose as DCC++EX

so, I used for as Command Station: Arduino Mega development board, a Motor shield, ESP8266-01 with logical level adapter, i2c LCD1602 (and than OLED) display + 4 servos connected at an expander board on i2c with 16 outputs using PCA9685 chip, using info from

- https://dcc-ex.com/get-started/assembly.html

- https://dcc-ex.com/get-started/wifi-setup.html

- https://dcc-ex.com/get-started/installer.html

For the throttle I used 2 versions:

- DCC++Ex Web Throttle (https://dcc-ex.com/throttles/ex-webthrottle.html)

- Engine Driver Android app (https://dcc-ex.com/throttles/engine-driver.html)

I was interested to control servos (for future turnouts) so I used info from:

- https://dcc-ex.com/reference/software/hal-config.html

- https://dcc-ex.com/reference/software/command-reference.html

- https://dcc-ex.com/reference/software/command-summary.html

Base commands for turnouts in DCC++EX are:

and for SG90 servo:

Easiest mode is to use web throttle (serial control)

So, for first servo (turnout), command is <T 200 SERVO 100 410 205 3>, where 200 is choose ID for turnout, 100 is VPIN (virtual pin for first servo connected at PCA9685), 410 is PWM number for throw (open) for SG90, 205 is PWM number for close position and 3 is slowest movement (0 is fastest movement).

For second servo (turnout), command is <T 201 SERVO 101 410 205 3>, where 201 is choose ID for turnout, 101 is VPIN (virtual pin for second servo connected at PCA9685), 410 is PWM number for throw (open) for SG90, 205 is PWM number for close position and 3 is slowest movement..

So, for third servo (turnout), command is <T 202 SERVO 102 410 205 3>, where 202 is choose ID for turnout, 102 is VPIN (virtual pin for third servo connected at PCA9685), 410 is PWM number for throw (open) for SG90, 205 is PWM number for close position and 3 is slowest movement .

So, for first servo (turnout), command is <T 203 SERVO 103 410 205 2>, where 200 is choose ID for turnout, 100 is VPIN (virtual pin for first servo connected at PCA9685), 410 is PWM number for throw (open) for SG90, 205 is PWM number for close position and 2 is medium movement.