Martin's corner on the web

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, not…

SAMD21D as a mass storage device

SAMD21D as a mass storage device

Experimenting with SAMD21D posing as a mass storage device using @Adafruit's TinyUSB library – planning on using this feature to expose configuration JSONs #IoT Added external SPI flash and using it as R/W mass storage device, works nice and smooth 🙂 Firmware configurations are now esposed as JSON file when you plug it in a…