Install the latest TEMPEST 2 firmware straight from this page over USB. Plug in, click flash, and the unit restarts on the new version.
Environmental monitor, NRG word engine, 4.4K real-speech playback and EMF meter.
Everything that goes on the TEMPEST's microSD card: the custom word list and the 4,409 recordings used by 4.4K Real Speech. Unzip it onto a FAT32 card (see SD card setup below).
Open this page in Chrome or Edge on a Windows, Mac or Linux computer. Phones and tablets can't flash.
Turn the TEMPEST on and plug it into the computer with a USB-C cable that carries data, not a charge-only cable.
Click Flash TEMPEST 2, choose the port in the browser's pop-up (it's usually named CP210x, USB Serial or CH9102), then click Install.
Wait for it to finish, about a minute. Don't unplug it until it says it's done. The unit restarts by itself, and the splash screen shows 0.92.
No port in the list? Windows may need the USB driver for the TEMPEST's USB chip. Install the CP210x driver or the CH9102 driver (installing both is fine), then unplug and replug. Also close Arduino, PlatformIO or any other program that might be holding the port, and try another cable or USB port.
The SD card holds the custom word list and the 4.4K real-speech recordings. If the TEMPEST shows NO SD CARD MOUNTED, says SD LIBRARY NOT FOUND, or the 4.4K Real Speech mode stays silent, the card is almost always the cause.
Generic, no-brand microSD cards are known to fail in the TEMPEST 2. They work for a moment after power-on, then stop responding once the screen is in use. Reflashing the firmware won't fix that; a different card will.
Use a name-brand microSD card: SanDisk, Samsung or Kingston. 32 GB or smaller is easiest.
Format it as FAT32. exFAT, the usual format for 64 GB and larger cards, won't work. On Windows, cards over 32 GB can be formatted FAT32 from a command prompt, for example: format X: /FS:FAT32 /Q /V:TEMPEST, where X: is the card's drive letter.
Download the TEMPEST 2 SD card files (zip, 222 MB). Open the zip and copy everything inside it to the top level of the card, so the card looks like this:
With the TEMPEST off, push the card fully into the slot until it clicks. Then turn it on.
To check it: go to NRG Speech, switch to Custom SD and then 4.4K Real Speech, and move between screens for a minute. Words should keep appearing and playing.
| Message | Meaning |
|---|---|
| NO SD CARD MOUNTED | No card found, or the card isn't responding. Reseat it; if it keeps happening, replace it with a name-brand card. |
| SD LIBRARY NOT FOUND | The card works, but customwords.txt isn't in its top level. |
| 4.4K speech silent | The af folder is missing or misnamed, or the card isn't responding. |
If you can't use Chrome or Edge, the TEMPEST can update itself from its SD card. This needs a working card (see above).
Download firmware.bin (v0.92, 1.6 MB).
Copy it to the top level of the SD card, keeping the name firmware.bin.
Put the card in the TEMPEST and turn it on. A blue Updating Tempest Firmware screen appears. Don't power off. When it finishes it deletes firmware.bin from the card. Restart the unit, and the splash screen shows 0.92.