Processor upgrade to a Teensy

Stephen, KD2NDR, has been working on porting the µBitx code to a Teensy.

He has added a few other features with the new expanded memory capability.  This includes an I2C 4×20 display, leaving many pins for other uses,  and digital beacon modes supporting all JT modes, WSPR and FSQ.   Transmission is triggered by a timer interval set through main menu.

The teensy real time clock is updated using a GPS module.   Stephen plans to add an option to set the clock manually or via a serial port at a later date.  His implementation also allows for dynamic setting of a maidenhead locator (4 or 6 character) based on the GPS data.

Planned features for a future build include an SD Card to store custom messages and logging for digital mode operations.   He also plans to provide numeric keypad support sot that text can be entered directly along with setting the frequency.   A voltage/ amps monitor for battery operation,  and an. swr meter, and more is planned.   Stephen promises to make the software available to constructors when he  gets more time to test everything in more depth.

In commentary on the measurement of amperage,  there were several suggestions for how to do this including the use of cheap “Hall effect” sensors.   Probably the best of these came from Arv, K7HKL, who suggests:

” An alternative approach for current monitoring might be available.  As part of a workbench system I built a dual-port DC voltmeter using an Arduino NANO.

“By using two ADC inputs I can measure voltage on both ends of a resistor and
the use the NANO software to calculate difference voltage.  This lets me

manually calculate the current from resistance and voltage.

“In a captive system this approach would work because the software would know the resistance value and thus be able to measure differential voltage and from that calculate current flow through that known resistance.

“Differential voltage measuring is necessary in cases where both ends of the device being measured are at some potential above ground, because the Arduino ADC can only measure relative to a ground reference.”

Reference

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