Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Accelerometer logger for rocketry

Registering accelerometer data may be useful in many areas like rocketry, vehicle, or in sports. For this as usually you need an accelerometer, microcontroller and memory where to store data. In this project there is a x axis Freescale MMA2201D accelerometer used that has a ±40g sensitivity.  All readings and interfacing is done by Motorola microcontroller HC908QT4. Data is written to 25LC640 EEPROM chip. Working with devices is easy – open jumper to enter measurement mode and close to start transfer memory contents to PC via serial interface. When you have data in computer it is up to you what to do then – so why not to start with simple graphs in excel? Continue reading

DIY 68HC908AB32 pulse-oximeter

Pulse oximeter is a device that mainly measures arterial blood oxygen saturation. As side measurement a pulse is also measured. Probably you’ve seen a small device that is put on a finger tip where one side of clip has a light source while another has a receiver. Depending on how much light is absorbed by hemoglobin parameter is calculated. This device is based on 68HC908AB32 microcontroller and is capable to measure pretty much same parameters as ones you’ve seen in clinics. Well we are not talking about how reliable this is, but anyway project is handy for personal experiments. And for sure at least it displays pulse correctly. Along with other features it has quite big (192×64) graphical LCD and four buttons for navigation. Project description is in Polish so be sure to use translator. Continue reading

Alarm clock knows you’re still in bed

Probably you’ve heard lots about various types of alarm clock that are trying to get ones out of the bed. Ones require to solve some math to turn it off, others use flying helicopter that has to be found and put back, but still after doing these tasks there is still a “risk” to get to bed again. But I bet this one beats them off as it detects you are still in bed. I know such alarms are real pain in ass and they don’t last very long, but they can save your but from meeting your boss because you’re late to work. This particular design uses a e-field sensor placed in the bed and detect whenever sleeper gets back to sleep after alarm triggers. E-field sensor is interfaced to PDA where alarm can be turned off – actually bumped off for nine more minutes and if sensor detect you’re still in bed it starts alarm again. So don’t be late again! Continue reading

Sleep O Meter – Now you will have a Good Night Sleep!

Go figure, after a long hard working day, there’s nothing better to have a good night sleep to recharge our exhausted body and mind. Sometimes, it’s easy said than done, as living in this 21st century that surrounded with numerous types of noise resources, it’s extremely hard for us to get a quality sleep without further disturbance. If you’re one of those who having insomnia, you don’t have to spend over hundreds or thousands of dollars arranging some appointment with the psychologist. Instead, you can build the Sleep O Meter and solve up the insomnia problem instantly! For your information, the main goal of the project is to track the movements of a person while he/she is sleeping. Let’s say, if the person has a good night sleep, then it will not move too many times during the night. Otherwise, if the person is disturbed by external factors, such as noise, light or vibration, frequent moves is going to happen throughout the night. By tracking the moves and the presence of the person, it able to count the number of… Continue reading

The Electronic Whoopie Cushion Deux – The Best Prank to Humiliate Somebody!

You’re a very humor person and you love to do something different to cheer someone up from the boring life? If you did, then this Electronic Whoopie Cushion Duex would be the excellent choice! Basically, it’s a device that built in a rubber bag with an opening on one end. The opening is working as a valve, which is allowing the air to be flowed into the bag, but restricted flow out of the bag. Normally, the bag is placed under a seat or between the cushion of a sofa. When a person is sitting on the chair, air is being forced out of the bag through the opening. The above mechanism will cause the bag to emit an embarrassing noise (It sounds like the person is farting). It isn’t hard to develop this fun stuff, all you need here is an MC33794 e-field sensor IC and a specially designed seat cushion sensor. Furthermore, you’ll need an MC68HC908QY4 microcontroller, as it helps you to sense when someone sits down or gets up from the sofa/chair! Honestly, this Electronic Whoopie Cushion… Continue reading

Antitheft Suitcase – You Won’t Be the Target of The Thieves Again!

You want to keep the important things in the suitcase, but you’re afraid that you’ll become the target of the thieves? Well, if you have plenty of money, then you might didn’t mind to buy a high end suitcase. Or, you might want to spend a few hours to modify and create your very own sophisticated “Antitheft Suitcase”! Honestly, the concept of this antitheft suitcase is derived from the security briefcase used by jewelry. In this project, a piece of metal foil under the handle needs to be connected to an MC33794 e-field sensor. This step is to sense when someone is carrying the briefcase with or without permission. In addition, three metal tabs are used to connect to other three e-field electrodes, which are serving as keypads to enter the arm or disarm codes. Normally, by only using a proximity electrode, the device can sense the suitcase distance from its owner. Furthermore, the MC68HC908 microcontroller-based system is included into the project. Its main purpose is to sound a buzzer alarm to alert the owner, if the stranger is picking… Continue reading