Mare & Gal Electronics

_________________ Work in progress _______ Last change: 22.10.2017 ______________

What I missed in my workshop is nifty small programmable precision voltage source which can be used as calibration voltage source for testing and calibration purposes. I decided to make one, because instruments which have word “calibrator” have price with same digits as there is vocals in this magic word.

Let’s start with block diagram:

Voltage calibrator – Block diagram

Continue reading ‘Precision voltage source – voltage calibrator’ »

Embedded board arrays in altium could be used for creating panels for multiplication during prototyping. Here is short illustrative example. In this example we will:

1. create single PCB board design (not covered here)
2. create and embed array with this single PCB
3. add some markers and holes
4. add panel cutouts

Final result, keep reading below…

Continue reading ‘Altium – working with embedded boards’ »

PreciPSU is an attempt to build high performance power supply. The idea started few years ago but it was never realised. Some major target performance specs are as follows:

• three isolated channels
• around 50W per channel
• 24V/3A output per channel
• lowest possible ripple at fastest response
• small size
• programmable via USB
• nice housing with minimalist user interface (2 plugs per channel, knob, button and small display

Update 15.7.2017: block diagram

PreciPSU Block diagram

Continue reading ‘PRECIsion Power SUpply project’ »

Low noise amplifiers are very useful. I built one with single BFG425W transistor with adjustable bias current. The schematic diagram is very simple:

LNA schematic diagram

and the PCB is 20x24mm:

LNA PCB

Continue reading ‘Adjustable gain LNA’ »

Smart nesting box is small wooden box for nesting birds. It is equipped with the live camera feed and some sensors. Four smart nesting boxes were made and three of them were placed in the wild. One was inhabited with the great tit in te early march 2017. After that, the bird laid 11 eggs. The bird then incubated eggs for 12 days. On the Easter Monday, the first shells cracked and newborns started poping out of the eggs.

I prepared the whole project for local school. The nesting boxes were made by 8 children aged from 11 to 14 during afternoon classes. It was great fun and the young scientists learned many new skills from electronics, materials, hand tools, crafting, programming, components, circuit design, biology, photography, physics, etc… The nesting box is described in detail here with all necessary production steps. Contact for further info is m@v4.si. The three nesting boxes placed in the wild have…

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This is Raspberry Pi GPIO connector breakout board with some additional features:

• “Real” or “passive” PoE with 12V output
• 5V DC/DC module
• Additional 3,3V regulator
• ESD protection on all GPIO pins
• two additional pins for each pin on R.Pi 40 pin GPIO connector
• Separate UART and I2C headers
• 3,3V Supply for periphery is selectable: from R.Pi or from external regulator
• STM32F070 or similar in TSSOP-20 housing for controlling additional sensor or any other hardware
• Jumper for Cortex-M0 / R.Pi UART connection

First prototype

Continue reading ‘Raspberry Pi breakout board with ESD, PoE and Cortex M0’ »

The Pressure, temperature and humidity sensor based on MS5637 HDC1080 originally (Rev. 2) operates via RS485 interface and multidrop HDLC-like protocol.  I decided to simplify this for use with Raspberry Pi, arduion or any other mass platforms. First, I took away the RS485 transceiver and second, I simplified the communication.

First adaptation was easy:

Remove RS485 driver and connect Rx/Tx to A/B

Continue reading ‘Simple Rh, T and p sensor with UART communication’ »

Gal ordered some PCBs from PCB-Way a while ago. It was multiproject panel with several PCBs. One of the modules was double sided revision of the Pressure, temperature and humidity sensor based on MS5637 HDC1080 which was posted while ago.

Pressure, temperature and humidity sensor based on MS5637 HDC1080

Continue reading ‘Pressure, temperature and humidity sensor based on MS5637 HDC1080 Rev.2’ »

The second version (here is larger 1st version with fixed angle) of R.Pi camera housing is smaller with 9 LEDs and possibility to adjust camera angle.

Adjustable housing with 9 LEDS for IR illumination

The 3D models are available on 3DcontentCentral or in GrabCad.

STL for 3D printing is on Thingiverse.

This is housing for R.Pi camera V2 with LED illumination.

Camera housing

It is 3D printable housing and PCB with 9 IR LEDs with enable.

Continue reading ‘Raspberry pi camera housing’ »