Author Archives: andy

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 | 22 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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100 articles

Shortest post ever: 100 articles published right after 4th blog anniversary, 4 most popular articles were viewed 100k times altogether, all articles 400k times (entry page does not count) and I still have no idea why I am doing this … Continue reading

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Pimp my bus: from 8-bit AVR to 32-bit ARM

Going to newer architecture is unevitable evolution. ARM series is particularly good choice as knowledge of its core functionality is to large extent portable across manufacturers. While ARM Cortex-M chips are close to 8-bit AVRs in footprint size and price … Continue reading

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Unf*cking my mac

Beer flushed thru air vents into Macbook mainboard killed it instantly. F-words came even faster as it was done by someone sitting next to me on the airplane from Germany to USA, a guy who called it an accident, not a … Continue reading

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Water Level Logger – Firmware over-the-air

Over time firmware stabilizes but rework never entirely completes, either due to inevitable bugs or further enhancements. Manual firmware update applied to couple stations in the field has relatively low effort and is just dauting task. While number of stations … Continue reading

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