The RESET button only needs to be depressed for less than 1 second. Doing so will cause the unit to reboot. If you have a "screen" monitor on the USB device, it will be disconnected. A good way to capture boot posting messages from within the unit is to have your command in a console ready to execute by depressing the RETURN key and you depress RETURN immediately after you depress the unit's RESET button, possibly allowing 1/2 second to allow kernel to recognize the new USB device, i.e. /dev/ttyACM0
## POWER
If your unit is powered OFF, simply depress the POWER button will start the unit. If the unit is powered ON, then depressing the POWER button and holding it down for 6 second will cause the unit to power down. The OLED display will go dark when the unit has successfully been powered down.
A) TODO: what happens when unit is powered ON and you depress BOOT?
B) TODO: what happens when unit is powered OFF and you depress BOOT?
C) To upload new binary image: depress the BOOT button and hold down, then while holding down the BOOT button disconnect the USB line and then reconnect the USB line and then lift up on the BOOT button. This sequence will cause the unit to await an upload of an image over USB to be stored in its FLASH memory. You can place the unit in this mode and then several minutes later perform the upload from your console, the unit will duly await an upload session. See further how to flash a new image in the section "Flashing Binary". Note: although the uploader may state it is trying to reset after successful installation of the new image, it seems that software attempt does not work and you have to manually depress the unit's RESET button to force a RESET. Remember, if you want to see the boot's posting, you should have your terminal ready to run "screen" so you capture the initial postings after you click RESET.
# Button Protocol For Uploading New Image
Pushing BOOT when the unit is currently running will not do anything. You have to shut the unit down first. So:
1) Depress POWER button for 6 seconds
2) Depress BOOT button and while depressed, click RESET button
3) Lift up BOOT button
The unit is now waiting for the serial console so commence an upload. You are not time restricted, so you can go through the above 3 steps and then 5 minutes later proceed with an upload in the command console.
These are progressve tests you can run to confirm how to access the unit's functionality and validate your workbench. Each exercise has it's own README.md
Exercise 01: ASCII ping-pong over LoRa (serial only). Using two units, each sends a message to the other and you monitor both units through two screen consoles.
