Determine your current version
First take a look at the following DM15L link from the manufacturer to get started on the DM15L firmware upgrade.
Then decide what version you want. Since I have the following Version, I decided to stay with the same, but upgrade it.
The SwissMicros DM15L is the Replacement of the HP15C.
- Turn off calculator
- Press and hold [E] button
- Press and release [ON] button
- Release first button pressed
Based on the picture I have MIB V23. As of October 3rd 2020, the latest Version is V29. You can download the firmware at the following page Firmware Voyager Series. Click here for the history information of the firmware.
Firmware Update Process
- Install the CP2102 Windows driver, get it from Silicon Labs drivers page
Make sure you Extract first, then install the drivers.
- Download the latest Firmware file for your device, using the ‘Target save as…’ function or I zipped a few version into this file.
- Connect the calculator with a standard miniUSB cable, preferably a shielded one. The calculator may be turned on or off before flashing
- Run the SwissMicros Firmware Update Tool
- Press “Open File …” and choose the Firmware file
- Choose correct COM port
- Press the “Program” button
- Push the “RESET” button in the left-hand pinhole closest to the corner on the backside with the paperclip
- Flash progress is being displayed and takes about 10-20 seconds depending on the firmware version
- After flash procedure is done, push the same “RESET” button again
I had quite a few PR Error during the upgrade. I reinstalled the Silicon Labs driver after unpacking it from the zip file, and it worked.
After the upgrade I set my contrast and Font and I was all set.
- [CHS]+[ON] starts the LCD mode setting
- Use [+], [-], [SUM+] and  to change the contrast
The models DM11, DM12, DM15 and DM16 include four font types: slim, bold, block and segmented. The combination +[ON] cycles through all three font types.