In this video I show as an example a USB to UART board. Eagle expects a Bitmap image with less than 256 color depth.The text image was made in Inkscape and since Inkscape can't export Bitmap (.bmp), I exported the image as PNG, then using IrfanView I lowered the color depth to 2 colors and saved as Bitmap.
Wednesday, January 24, 2018
EAGLE CAD Tips | How to Add Custom Image Logo to Your PCB
In this video I show as an example a USB to UART board. Eagle expects a Bitmap image with less than 256 color depth.The text image was made in Inkscape and since Inkscape can't export Bitmap (.bmp), I exported the image as PNG, then using IrfanView I lowered the color depth to 2 colors and saved as Bitmap.
Saturday, October 28, 2017
How to use A4988 stepper motor driver module tutorial
A4988 stepper motor driver module
This
driver can be used to easily control a bipolar stepper motor or a
uni-polar stepper connected in a bipolar mode. Can output up to 2A per
phase (with a heatsink) and works with motor voltages from 8 to 35
volts.
- Simple step and direction control interface
- Five different step resolutions: full-step, half-step, quarter-step, eighth-step, and sixteenth-step
- Adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motor’s rated voltage to achieve higher step rates
- Intelligent chopping control that automatically selects the correct current decay mode (fast decay or slow decay)
- Over-temperature thermal shutdown, under-voltage lockout, and crossover-current protection
- Short-to-ground and shorted-load protection
Library for A4988 stepper motor driver using timer interrupt
Update 4, October, 2023: I have made a new library for controlling stepper motor drivers that supports multiple motors and has a better acceleration algorithm. It can also coordinate xyz steppers.
This library is designed for AVR ATmega328 microcontroller, but with few adjustments can work with any AVR microcontroller with at least 3-4 Kb of flash program memory.
At the moment only one motor is supported.
Features
- the interrupt can be triggered by Timer0 or Timer1
- automatic microstepping mode selection
- can work with constant and very low speeds
- accelerated speed mode, with separate acceleration and deceleration settings
- can work with only one pin of the microcontroller if the rest are hardwired
Characteristics:
Features
|
Program Memory
|
Data Memory (SRAM)
|
All enabled
|
3552 bytes
|
40 bytes
|
Acceleration, no microstepping
|
3088 bytes
|
40 bytes
|
Microstepping, no acceleration
|
2104 bytes
|
14 bytes
|
No microstepping, no acceleration
|
1724 bytes
|
12 bytes
|
Compiled using avr-gcc (WinAVR 20100110) 4.3.3 and -Os optimization level and MATH_LIB = -lm.
If MATH_LIB = -lm is commented out in Make file, the memory with all functions enabled is 6520 bytes program and 304 bytes data memory.So allways uncomment MATH_LIB = -lm.
Saturday, June 24, 2017
Homemade Cheap ESD Safe Electronics Storage Box
Storing and finding electronic components can be a pain. I tried many solutions over the years until I found a solution that suits my needs - making boxes from 2mm plastic sheets. The cost is very low and can be made in whatever sizes you need.
Thursday, June 8, 2017
Salvage a VFD from a broken DVD
To create all this circuitry from scratch would be difficult. The ET16312N driver needs +5V, +12V and -24V. Also you would need to create an AC signal, multiplex the grids, drive the anodes, etc. but all this is already build for oyu on the front board. The power supply from the DVD Player can be used but I want to power the VFD from batteries so I will try to make a power supply myself.
The weird thing is that on the 12V line the VFD driver draws about 53 mA even if the display is off or dimmed. On -24V it draws about 6 mA. So yeah, it is not well suited for batteries unless you physically turn of the power using a transistor controlled by the MCU when the display is in standby.
Philips DVP5960 Front Board together with Crapduino |
Saturday, June 3, 2017
Library for interfacing AVR microcontrollers with ET16312N VFD (Vacuum Fluorescent Display) driver
I had a broken Philips DVP5960 DVD player and I thought it's a good idea to salvage and use the VFD display in some project. And so this code was born.
Vacuum Fluorescent Display (VFD) from a DVD Player controlled by AVR MCU |
To know more about the communication protocol between the microcontroller and the VFD driver chip, visit this post Salvage a VFD from a broken DVD.
Sunday, February 19, 2017
Library for reading internal temperature sensor on AVR microcontrollers
A few AVR microcontrollers have internal on-chip temperature sensors. The sensor is a diode that produces a temperature dependent voltage. This voltage is measured with the ADC. According to Atmel the typical accuracy of temperature measurements over the full temperature range of the AVR is ±10°C but after calibration the accuracy can be ±1°C over 20°C to 55°C using one-point calibration.
The calibration can be done using one-point calibration and compensation or two-point calibration and compensation. One-point calibration is the easiest - subtract the ambient