There isn’t much open hardware medical instrumentation projects that can be considered completed and reliable. MobilECG project could pretend to be one that could compete with medical grade devices. Actually Péter, the founder of project, intended to collect decent amount of funding to get medical certification. But campaign didn’t went as planned, so he decided to make project open. Since the most of work is already done it would be sad to see project die. The decision to make it open is plausible and maybe it will completed with help of community.
MobilECG is very compact device that can measure ECG using 12 leads. The ECG signal is digitized using TI’s ADS1278 eight channel ADC. For interfacing and communication to host there are two AVR micros used – Attiny24 and ATU64. Schematic is developed using KiCAD software. Firmware isn’t complete – only minor functionality with several known bugs. Anyone with biomedical engineering knowledge will definitely see the potential of this device that can be attached to any device like PC, android or other and explore own ECG signals.
Digitally controlled electronic loads are great for many purposes. First of all you can test batteries by discharging them with known current or measure power supply capabilities at high loads and so on. Jakub has been testing batteries and power supplies for some time, but his setup was manual. Eventually he decided to build more automatic solution and so he came up with electronic load Arduino shield.
The load is based on FET which gate is controlled by op-amp which allows to maintain constant voltage or constant current across load. The load can withstand 70W power dissipation with up to 10A current. Custom PC software allows reading voltage and current data also it accepts control commands like setting constant power and constant resistance modes. The FET on shield has to dissipate quite a lot heat so there is an active cooler installed which keeps temperature within safe margins.
Webcam may be the cheapest way of monitoring your home while you are out. All you need is to leave your PC connected with camera so you could connect to it using remote connection software like VNC or Teamviewer. Ruijc wanted to look after his cat using this technique, but found out that steady camera doesn’t cover all the areas of the room, so he started a project where he would be able to control camera tilt and rotation remotely.
He built a simple PIC16F88 microcontroller based circuit which would drive two servo motors. Motors simply tilt and rotate camera to point at any spot of the room. Additionally he added a transistor driven LED lamp, which also can be turned on when there is dark in room. Device is connected to PC using RS232 interface. He wrote a simple VB based software which allows controlling camera position, switch LED and even see camera image. Since this is not web based access, you need to connect to computer remotely to see whats going on. Anyway this is really simple solution that does it’s job pretty well.
Alex had previous experience with his GPS logger, so recently he decided to build another project called GPS alerter which would send SMS when device is located in a certain area. Device also is equipped with accelerometer which allows detecting movement, so it could activate GPS module and start getting data. This helps to preserve battery life as there is no need to check coordinates while it is at same coordinates.
For this project he uses Atmega8 microcontroller which read GPS data through serial port. To send SMS messages there is an old Nokia 3210 cell phone used which is fairly easy to interface.