PPM Encoder

No PPM Encoder? Make your own with Arduino pro mini
BuzzsArduinoCode/PPM_Encoder.h at master · davidbuzz/BuzzsArduinoCode
PPMEncoder - Arduino Libraries

RC Groups - View Single Post - FRSKY Taranis "How to" Thread

Capturing a double-pull of a momentary switch

---

Thought I'd share this snippet for capturing a double-pull of a momentary switch. Applications include anywhere a 'safe' switch is required, for example for arming a motor or u/c operation.

Operation:

Pull SH twice within a 1.5 second window. The second pull is captured as an edge in L3.

Code

L1 Edge(L02, [0:instant]) Duration(1.5s)

L2 ( Edge(SH-down, [0:instant]) )

L3 L01 AND L02

How it works

• Pulling SH generates an edge in L2, which cascades to L1 a clock tick later.
• Because an edge is true for just a single clock tick, L3 is true only from the second pull. This must be within the time period set in L1.Duration (1.5 secs).

Simple demo - each double-pull toggles a sticky switch:

L4 Sticky(L03, L03)

FrSky D4R-II upgrade to D16 protocol

Courtesy of Mike Blandford, of course!

FrSky D16 firmware for D8 receivers - RC Groups
RC Groups - View Single Post - FrSky D16 firmware for D8 receivers

And from Midilic...

FrSky D4R-ii – components, layout, and pinout – fishpepper.de

RC Groups - View Single Post - DIY FrSky TX/RX Modules

PrusaSlicer: Removing unused system system settings

In {Print, Filament, Printer} Settings, for each systems setting you want to keep:

• save a copy with your own name, e.g. "marhar PLA"

Now rename PrusaResearch.ini to PrusaResearch.ini.SAFE in the vendors directory.

On Mac, that's Library/Application Support/PrusaSlicer/vendor

FrSky SxR Gains

Mike Blandford confirms:

In auto-level mode, the individual gains set using the script affect the amount of servo movement output to get to level. The channel 9 gain affects the speed of the servo response..

RC Groups - View Single Post - FrSky S6R 6CH Receiver With 3-Axis Stabilization With Smart Port Telemetry

Logic Shrimp Analyzer 1.0

Old, so here's some links before they disappear.

• Logic Shrimp logic analyzer - DP
• Logic Shrimp v1 logic analyzer - Seeed Studio
• Index of /ols

RIGOL Scope Tutorials

Basics of Oscilloscopes  - How to use an Oscilloscope | RIGOL

EDU Basic Lab Guide.pdf

Viewing Wyze Cam on Computer

tl;dr: Wyze supports RTSP with a bit of effort.

Directions and download here:
https://support.wyzecam.com/hc/en-us/articles/360026245231-Wyze-Cam-RTSP

• Download the firmware
• Boot Cam with firmware on SD card.  It will take 3-4 minutes to install.
• In your phone app, Settings / Advanced Settings / RTSP
• Turn on RTSP toggle
• Set name and password, click Generate URL
• Watch with VLC

Reference: "Blue Pill" STM32F103

https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill

• Warning: This board may have a wrong value of resistor on the USB D+ pin. Instead of a 1.5kΩ it has either a 10kΩ or 4.7kΩ resistor. This can be solved by replacing the resistor with the right value.
• R10 should be a 1.5kΩ.

References

• Easy & Powerful Arduino Alternative? STM32 Beginner's Guide - YouTube
• LeafLabs Documentation Index — Maple v0.0.12 Documentation
• Getting Started with STM32F103C8T6 STM32 Development Board (Blue Pill) using Arduino IDE: Blinking LED
• Enabling USB on a Blue Pill • JeeLabs
• [STM32]: Overcoming wrong pullup resistor at D+ in blue pill
• Installing the STM32 USB Bootloader, Easily! [SEE DESCRIPTION] - YouTube

Reference: Geekcreit® 375pcs 3MM 5MM LED

https://www.banggood.com/Geekcreit-375pcs-3MM-5MM-LED-Light-Emitting-Diode-Beads-Resistance-Lights-Kits-Bulb-Lamp-p-1027601.html

Current : 20mA

Voltage: 3V

Color: RED, BLUE, YELLOW, GREEN, WHITE

Total Quantity: 375pcs

Packed in a box

375pcs Five Colors 3mm,5mm Round Bright Light LED Assortment Kit
Color	Size	Wavelength        (nm)	Voltage     (V)	Current     (mA)	Intensity   (mcd)	Lens Color	Quantity
Red	3mm	620-630	1.9-2.1	20	3000-4000	red	50pcs
Red	5mm	620-630	2.8-3.1	20	4000-5000	red	25pcs
Yellow	3mm	580-590	1.9-2.1	20	5000-6000	yellow	50pcs
Yellow	5mm	580-590	2.8-3.1	20	4000-5000	yellow	25pcs
Green	3mm	570-573	3.2-3.4	20	10000-12000	green	50pcs
Green	5mm	570-573	3.0-3.4	20	12000-14000	green	25pcs
White	3mm	610-620	1.8-2.2	20	3000-4000	clear	50pcs
White	5mm	500-620	3.0-3.2	20	12000-14000	clear	25pcs
Blue	3mm	460-470	3.2-3.4	20	3000-4000	blue	50pcs
Blue	5mm	460-470	3.0-3.4	20	5000-6000	blue	25pcs

Reference: TTGO ESP32 1.14 Inch LCD LILYGO

On Banggood.
Demo: https://github.com/Xinyuan-LilyGO/TTGO-T-Display








Random notes for the BG page:

IPS ST7789V 1.14 Inch has 135x240 pixel
Display has 340x240 pixel resolution
LCD resolution 240x135

Driver ST7789 (uncomment #define ST7789_DRIVER in User_Setup.h)
Color order Blue-Green-Red (uncomment #define TFT_RGB_ORDER TFT_BGR in User_Setup.h)
Device TTGO_T_Display (uncomment #include in User_Setup_Select.h)


the display seems to require its own graphic library, on github:
github.com/Xinyuan-LilyGO/TTGO-T-Display
github.com/Bodmer/TFT_eSPI

Q:Is the SPI bus accessible for other sensors (other than the display)?
A :  VSPI default pins are connected to display and are not available on the headers. HSPI by default uses GPIO 12 to 15. Unfortunately GPIO14 (CLK) is apparently also used by the display BL function. So I assume you will need to remap 14 to another pin to get CLK. (I have not tried this).

Seems to be a difference in this regard between version 1.0 and 1.1. The board I received says V1.1 in silkscreen. According to the pin-out for this version on GitHub GPIO4 (not GPIO14 as indicated above) is used for BL.

Battery-Molex-Pico-1_25mm

Use this library for the display: github Bodmer TFT_eSPI
Look on github for Tetris Clock and "TTGO_example", you will find a library and example I wrote for this board. It has an explanation page that shows how the board looks when running it.

What pins provide me with access to the serial port? TX / RX?
A: A "standard" ESP32 has more pins, the default pins are 3 (Rx) and 1 (Tx) for Serial(0), 9 (Rx) and 10 (Tx) for Serial1, and 16 (Rx) and 17 (Tx) for Serial2. As you can see, with the limited number of pins on this TTGO board, none of them are there. But the good news is that the "Serial.begin" function has an option to change the pins! By using "Serial2.begin(9600, SERIAL_8N1, 25, 26);" you have the Serial2 port on pins 25 (Rx) and 26 (Tx). I tested this today, it's working like a charm!. It's NOT working on pins 37 and 38 (and maybe other pins), but it IS working on pins 25, 26, 27 !!!

This board is an 'ESP32 dev board' and it can be used with the arduino IDE but because it isn't an arduino you'll need to configure the IDE with the new board by adding an 'additional board manager url' to arduino preferences.
Some details of how to do this are here:  youtube mBaS3YnqDaU

The board comes loaded with the arduino sketch from here:
Search github Xinyuan-LilyGO TTGO-T-Display

There is a good youtube vid explaining it a little here: youtube qj9dN-Ginxc
The above is a great intro into how to use the 320x240 display and even makes use of the two buttons near the usb port to show voltage and scan for wifi networks.

https://github.com/Xinyuan-LilyGO/TTGO-T-Display/blob/master/schematic/ESP32-TFT(6-26).pdf

----

install quick notes from https://www.youtube.com/watch?v=UE1mtlsxfKM

Arduino / Preferences  / Board manager url: https://dl.espressif.com/dl/package_esp32_index.json

Library / Boards / Board manager: esp32

Tools / Board / TTGO Lora32-OLED V1

File / Examples / ESP32 / ChipID / ChipID     ESP32 Chip ID = FCB5F9AB6224

Tools / Manage Libraries... / install tft_eSPI by bodmer

edit libraries/TFT_eSPI/User_Setup_Select.h

    //#include <User_Setup.h>           // Default setup is root library folder

    #include <User_Setups/Setup25_TTGO_T_Display.h>    // Setup file for ESP32 and TTGO T-Display ST7789V SPI bus TFT

File / Examples/ TFT_eSPI/examples/Generic/alphaBlend_Test

https://github.com/me-no-dev/arduino-esp32fs-plugin/releases/ ESP32FS-1.0.zip

(base) ArduinoBase $ mkdir tools

(base) ArduinoBase $ mv ~/Downloads/ESP32FS tools

restart Arduino

Tools / ESP32DataUploader

Tools / Manage Libraries... / jpegdecoder by bodmer

File / Examples / JPEG Decoder / Other_Libraries / SPIFFS_Jpeg

Tools / ESP32DataUploader

Using the Tiltmeter

Setup

Be sure you have run the self-test to set level and stick travel.

Depending on servo installation, pitch may be reversed.  That's indicated in parentheses below.

Set gain to maximum, it will make for largest pitch variation.

Ailerons

Moving stick to left is correction for roll right.  Left aileron moves up.

Move stick to left.   Note audio-pitch goes up (or down).

Hold plane, twitch right wing down. You should hear audio-pitch up (or down).

Twitch left wing down.  You should hear audio-pitch down (or up).

Rudder

Moving stick to left is correction for yaw right.  Rudder moves left.

Move stick to left.   Note audio-pitch goes up (or down).

Hold plane, twitch noseto right. You should hear audio-pitch up (or down).

Twitch nose to left.  You should hear pitch down (or up).

Elevator

Moving stick back is correction for pitch up.  Elevator moves down.

Move stick down.   Note audio-pitch goes up (or down).

Hold plane, twitch nose down. You should hear audio-pitch up (or down).

Twitch nose up.  You should hear audio-pitch down (or up).

(note) I typed the above because my brain gets confused when I tune planes with servos reversed.  Maybe I should add a reversing button to the tiltmeter so that I can match my brain thinking, which is

Pitch up = Left aileron up

Pitch up = Elevator up

Pitch up = Rudder left

OctoPrint: Turning on an LED during printhead heating

I do this so I can more easily inspect the printhead for ooze, etc.

Install OctoPrint plugin "GCODE System Commands"

https://github.com/kantlivelong/OctoPrint-GCodeSystemCommands

Configure Plugin

OCTO 21 /home/pi/scripts/led-on
OCTO 22 /home/pi/scripts/led-off

Use This Code

$ cd /home/pi/scripts
$ cat led-on.c
void main()
{
  system("echo 23 >/sys/class/gpio/export");
  system("echo out >/sys/class/gpio/gpio23/direction");
  system("echo 1 >/sys/class/gpio/gpio23/value");
}
$ cat led-off.c
void main()
{
  system("echo 0 >/sys/class/gpio/gpio23/value");
  system("echo 23 >/sys/class/gpio/unexport");
}

$ make led-on led-off
(ignore warnings)

$ sudo chown pi.gpio led-off led-on
$ls -l led-on led-off
-rwxr-xr-x 1 pi gpio 7984 Jun  5 20:33 led-off
-rwxr-xr-x 1 pi gpio 7984 Jun  5 20:33 led-on

Add OCTO commands to to your slicer gcode template

(for Prusa-Slicer, in Printer Settings/Custom Gcode/Start GCode).
Mine looks like this:

G28 W ; home all without mesh bed level
OCTO21 ; turn on external light
G1 Z30 ; raise printhead for visual inspection
M109 S[first_layer_temperature] ; wait for extruder temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
OCTO22 ; turn off external light

Raspberry Pi Blink in shell

#!/bin/sh

# release the pin on exit
trap 'echo 0 >/sys/class/gpio/gpio23/value;echo 23 >/sys/class/gpio/unexport' 0

echo 23 >/sys/class/gpio/export
echo out >/sys/class/gpio/gpio23/direction

while true; do
  echo 1 >/sys/class/gpio/gpio23/value
  sleep 1
  echo 0 >/sys/class/gpio/gpio23/value
  sleep 1
done


# for input:
#  echo 23 >/sys/class/gpio/export
#  echo in >/sys/class/gpio/gpio23/direction
# read value:
#  cat /sys/class/gpio/gpio23/value
# release a pin
#  echo 23 >/sys/class/gpio/unexport

Troubleshooting SiLabs Driver on Mac notes

tl;dr:

• 99% chance it's a USB cable problem.
• If you're a manufacturer, blah blah major and minor device numbers

Looking for this device;

• /dev/SLAB_USBtoUART

Do you have the driver software installed?

• find /Library/Extensions/SiLabsUSBDriver.kext

Is the driver loaded?

• kextstat | grep -i silabs

Loadin the driver:

• sudo kextload /Library/Extensions/SiLabsUSBDriver.kext

This does something:

• ioreg -p IOUSB -l

watch console.app and plug device in.