arduino 2 button keyboard I wanted a simple keyboard with play and pause media keys to make it convenient to control my music. To handle the USB, I used a STM32F103 based "blue pill" board because they're
gps GPS module measurements, part 2 After the previous tests [https://blog.dan.drown.org/gps-module-measurements/], I ordered another GPS antenna to improve the signal conditions. They're just the cheap puck style antennas with SMA connectors ($10 on Amazon)
gps GPS module measurements Starting point I got a u-blox NEO-6M and I wanted to compare it to my NS-T. Since I don't have a frequency counter, I decided to try creating one myself. The hardware I
ntp PPS over USB Goal For keeping your system clock on time, you can't beat the Pulse Per Second (PPS) signals available from $10 GPS modules. They typically have better than 100 nanosecond accuracy [https://blog.dan.
arduino Navspark UART/USB bridge I created a program on the Navspark to send characters at 150 microsecond intervals and then received them on a PC. Below is a histogram of how long it took between characters: The