These sites are great go-to’s for display laser information and tools: photonstreams.com rekordbox.tools
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Mains zero crossing detect
Useful resources for this https://dextrel.net/dextrel-start-page/design-ideas-2/mains-zero-crossing-detector https://www.eevblog.com/forum/projects/mains-zero-crossing-detection Zero crossing detect ICs https://www.rohm.com/products/power-management/ac-voltage-zero-cross-detection-ics/bm1z001fj-product
SIM Cards-IoT
Having to manually select networks For typical SIM cards, a phone or GSM module can scan all available networks, however it will only try and connect to those for which the SIM is authorized. That is because these type of SIM cards have steering – the SIM card can instruct the phone / GSM module […]
LTE-M Coverage
UK Coverage O2 coverage map
BLE Adveristing data
Advertising packets Packet reguarley broadcast by the advertising device (peripheral). manufacturer_data Can be used for custom data bytes for your particular application. BLE scan response Packet sent by the advertising device (peripheral) upon the reception of scanning requests (it is a response to a device scan). Typically has more data than the advertising packets – […]
Useful apps
GATTBrowser for iOS is great for testing GATT implementations.
GATT
GATT defines the way that two Bluetooth Low Energy devices transfer data back and forth. Uses the generic data protocol called the Attribute Protocol (ATT). GATT server & client The peripheral is known as the GATT Server. It holds the ATT lookup data and service and characteristic definitions The phone/tablet is the GATT Client which […]
iOS devices
BLE is the only wirelss comms option outside of HID devices that avoids the need for MFi certification and the associated onboard security hardware requirements.
Resistance values
How high can pull up/down resistances be? The value of a pull-up or pull-down resistor is limited by the leakage current of whatever it is pulling. For instance, say you have a 100K pull up resistor on a mosfet gate connection, and the mosfet has a gate leakage current specification of +-10uA. Your 100K resistor […]
NMEA 2000
NMEA Docs They’re generally paid, however the following is available online: National-marine-electronics-association-nmea-2000-standard-for-serial-data-networking-of-marine-electronic-devices-main-document NMEA 2000 Basics 250kbps CAN Bus 29bit identifier (ISO11783 standard) 8 byte data field Open Source Libraries The NMEA2000 library by Timo Lappalainen basically makes NMEA2000 possible for the masses (it’s a big and complex standard!): https://github.com/ttlappalainen/NMEA2000