Martin's corner on the web

18 solar panels and a 6kW inverter

Decided to go for 18 #solar panels and a 6kW inverter instead of 14 panels and a 5kW inverted because the 14 panels I originally planned produce over the recommended MPPT voltage for the inverter,and donโ€™t split well into 2 strings. Learning as I go, shouldโ€™ve consulted better

Roof rafters under asphalt shingles

Roof rafters under asphalt shingles

Tip for non-invasive detection of roof rafters under asphalt shingles for #solar panels installation:these are clearly visible on an early morning with freezing temperatures. Marked mine with paint and took a ton of pictures at 6 am today,before the sun rises and frost marking go

Fronius Smart Meter

Fronius Smart Meter

Received the Fronius Smart Meter, it limits the power export of my yet-to-build solar roof installation. Exporting power here is a bureaucratic hell, I will not subject myself to it by zeroing on the export. The inverter itself, a @froniussolar Primo GEN24 5kW due in 3 months ๐Ÿ™

South-facing slope of the house roof

South-facing slope of the house roof

Sketched the south-facing slope of the house roof to identify where/how to fit the 14 Q CELL 355W #solarpanels I bought earlier (sized 1.68m x 1m), looks like I can fit 4 more panels in the future and split them into two strings. A good site, if you want to do that same thing inโ€ฆ

GUI controls for your home automation

Join me on March 9th, lets chat on how to create GUI controls for your home automation ๐Ÿ™‚ (in Bulgarian) https://dev.bg/%D1%81%D1%8A%D0%B1%D0%B8%D1%82%D0%B8%D0%B5/webinardiy-%d0%b3%d1%80%d0%b0%d1%84%d0%b8%d1%87%d0%bd%d0%b8-%d0%ba%d0%be%d0%bd%d1%82%d1%80%d0%be%d0%bb%d0%bd%d0%b8-%d0%b8%d0%bd%d1%82%d0%b5%d1%80%d1%84%d0%b5%d0%b9%d1%81%d0%b8-%d0%b7%d0%b0-iot/?instance_id=1244 #IoT #NodeRed #raspberrypi #mqtt

SMB20 Geiger tube

SMB20 Geiger tube

Received a SMB20 Geiger tube to replace the J305 I had on my Geiger Computer project. Should work much better outdoors, the J305 goes crazy on sunlight. Works well after adjusting the CPM to uSv/hour constant, see more here https://cs.stanford.edu/people/nick/geiger/

Relay coils dissipate that much heat

Relay coils dissipate that much heat

TBH, I didn't realize relay coils dissipate that much heat when energized. This one gets to nearly 29*C. TE has an interesting application note on PWM-ing the relay to keep temp and energy consumption low. https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=13C9133_DC_Relay_Power_Reduction_AppNote&DocType=CS&DocLang=EN

SAMD21+RFM95 on a 1400mAh battery

SAMD21+RFM95 on a 1400mAh battery

Experimenting how many #LoRaWAN messages (20 bytes payload that includes battery reading and internal CPU temperature @ SF7) can a SAMD21+RFM95 send on a 2000mAh Li-Polymer battery. Currently at 23392 messages, and battery is at 3.826V (80% full).. aiming at 120K messages. #IoT Si it died today at 68323 transmission. The battery is 1400mAh, notโ€ฆ