Author Archives: andy

e-snowflake revisited

Four years ago I made microcontrolled snowflake decor using home made PCB based on toner-transfer process. I got back to this idea late in 2015 to make short batch for family and friends. Second version was about fixing design issues … Continue reading

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3D printed rain gauge

Water level monitoring on river basin under observation was completed mid 2015. From rainfall-rainoff modelling perspective rainfall capturing was missing. Low budget, 3d printer at home and some spare time pushed me to design my own rain gauge. Before autumn … Continue reading

Posted in 3D printer, Electronics | Tagged | 4 Comments

Outdoor device? Bundle up your PCB.

Winter is coming… actually it has already come bringing constructor’s nightmare. Sudden freezing cold caused unexpected and massive restarts of all field stations. All because of the same hardware reason. Reason impossible to happen. All that because circuit boards were not … Continue reading

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Bitten by dead FTDI chips

Counterfeit chips have always been on the market. Most of the time stories were told about fake high-end components like computer GPUs. I did not worry and over last couple years I bought hundreds genuine chips from China. They were … Continue reading

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Toner transferred PCBs

Thanks to Chinese providers printed circuit board fabrication has never been so cheap. With PCB comparison tool it is also darn easy to choose from. Sometimes though old’ye home made PCB is what you are looking for. So I made … Continue reading

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Kicad upgrade: push & shove and freerouting revisited

Kicad PCB toolset changed a lot over last two years. Great contribution from CERN is merged with stable release on one hand, new library format and projects migration necessity on the other. Meantime Freerouter cooperative tool disappeared and my reluctance to move … Continue reading

Posted in Electronics, Software | 23 Comments

EMI shielding

Close GSM antenna proximity to bare PCB was troublesome latching microSD. Using most resilient flash cards nearly solved the problem. Extra shielding would help to prepare for worst field conditions like area of weakest GSM signal leading to highest emission and … Continue reading

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OSX mishandles SSID with @ sign

Lately at the airport so-called user-friendly Apple operating system  was stubbornly failing to log into WiFi without giving me any clues. Meanwhile Android phone was happily sucking data from the same hotspot. It turned to be an OSX (Yosemite 10.10.4) … Continue reading

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GSM antenna freezes microSD

Dealing with RF is tricky part of electronic design, even though I never had significant issues with GSM in my prototypes. Advancing in WLS project however I discovered a nasty issue with micro SD prone to lock up on interference … Continue reading

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External RAM and lost MCUCSR

Atmega’s MCUCSR status register gives info about restart reason like regular reset-pin shorted, watchdog initiated reset, or brown-out on low voltage from power supply. Pieces of valuable information for device defect tracking. Reading MCUCSR early in test program was fine, … Continue reading

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