June 2020 – Beyondlogic

ANSI C Basic Lightweight NMEA Parser for GPS

June 23, 2020 Craig Peacock 0

For a recent OBD2 (vehicle/fleet data-logging) project running on a Raspberry PI Zero, I needed access to GPS data – both position/speed and time. The Raspberry PI doesn’t include a Real Time Clock (RTC). Upon boot, it doesn’t know what the actual time it is, unless it has access to a network and can retrieve the time via Network Time Protocol (NTP). With the logger fitted to a vehicle, a network connection wasn’t always available for NTP. Robust, feature rich software packages currently exist such as gpsd – a GPS service daemon. gpsd can also be used used in conjunction …

SWCAN Single Wire CAN Transceiver Breakout Board

June 19, 2020 Craig Peacock 17

Single Wire CAN (SAE J2411) is commonly used in cost-sensitive Automotive applications where speed and cable length is not as onerous. It is also useful in applications were a traditional CAN differential pair is physically not possible. For example, on Type 2 Mennekes connectors used for Electric Vehicle (EV) charging, the communication between the supply equipment and the vehicle is performed via a PWM signal on a single Control Pilot (CP) pin in respect to earth. Tesla has used SWCAN to digitally communicate over this single pin. Various SWCAN drivers are available and generally share the same compatible pinout (SO8 and …