Author Archives: Lamja.com

Arduino UNO Controlling 20 Servos With 15 bit Precision And Low Jitter

I made a program (or sketch) for Arduino UNO controlling 20 servos: I have used Arduino with hobby servos often, but I was getting annoyed of the jitter of the standard servo-library. So I took my newly acquired Rigol DS2072 … Continue reading

Posted in Software projects | 67 Comments

Moody Useless Machine

This is a project i did a while ago. I made one for my self and two as gifts. I decided to crack open the one I had left, to get some photos and video of the inside. I also … Continue reading

Posted in Hardware projects | 185 Comments

RC car head, tail and brake lights LED control board

This is a simple way for adding head lights, brake lights and tail light for a RC car. I used a LM324 op-amp to filter the PWM signal from the servo channels. The throttle channel is heavily filtered to get … Continue reading

Posted in Hardware projects | 4 Comments

LamjaStep – Bipolar Stepper Motor Driver

Here is a schematics preview of the driver. There might be som minor typos in this. I will post PCB layout soon. I’m working on a new stepper motor driver. It will have 1/32 -1/128 microstep resolution, power save feature,  … Continue reading

Posted in Under development | 29 Comments

Operational amplifier basic circuits

There are some standard op-amp circuit that are often used. Because of it’s high gain, the calculations becomes easy. Mostly, the op-amp is used in a negative feed-back configuration, feeding the output back to the negative input. This will limit … Continue reading

Posted in Electronics in general | 1 Comment

Controlling a bipolar stepper motor using microstepping

  Stepper motor basics A standard bipolar stepper-motor usually will have 1.8 degree steps. That will be 200 steps per revolution. It has two motor windings (phase A and B) that must be controlled. The motor is rated at some maximum current per … Continue reading

Posted in Electronics in general | 11 Comments

Double PWM controlled H-bridge for interfacing with an Arduino

This is a double H-bridge that can be used with PWM to control the output current. It uses some NAND logic to make sure there will be no shoot-through shortening the supply voltage by opening both high-side and low-side MOSFET’s … Continue reading

Posted in Hardware projects | 14 Comments

How to design a circuit from NAND-gates only,using a truth-table

Sometimes you’ll need some given digital outputs for some given inputs in your project. At least I do. There are several ways to do this, but I will use the Karnaugh mapping method.   First let’s be familiar with some … Continue reading

Posted in Design and simulation | 1 Comment

Simple Pulse Generator using LM324 opamp

This is a simple pulse generator to use for testing purposes. It uses the LM324 operational amplifier, and the frequency can be controlled with a potentiometer. The LM324 chip is not that fast, so the frequency will be limited. I … Continue reading

Posted in Hardware projects | 2 Comments

CD4028/HEF4028 as a sub-circuit simulation in LTSpice

This is an article on how to simulate 4028 in LTSpice. If you need a custom IC that you know how to simulate, This method might be of interest. The principle is to create a schematics with the same name … Continue reading

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