Voyager Series Instructions

Firmware Update


Use the SwissMicros Firmware Update Tool for flashing the calculator, see

Don't worry, it is not possible to break or brick the calculator with this or any other upgrade procedure.

All programs, registers, etc. will be lost. If these need being preserved, do a backup BEFORE starting the firmware update.

  • Install the CP2102 Windows driver, get it from Silicon Labs drivers page
  • Download the latest Firmware file for your device, using the 'Target save as...' function
  • 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


Install/update the following software

  • Download and install CP210x USB to UART Bridge VCP Drivers from Silicon Labs drivers page
  • Download and install MacPort (
  • Open the Terminal application
  • sudo port selfupdate
  • sudo port upgrade outdated
  • sudo port install lpc21isp
  • close the Terminal application

Console session with the device

  • Open the Terminal application
  • Connect the calculator
  • Put the unit in terminal mode: [ON]+[C]
  • Start a console session: screen /dev/tty.SLAB_USBtoUART 38400,8,n,1
  • The calculator menu is now active (press ? for help)
  • Put the unit in normal mode: press any key
  • End the console session: press [CONTROL]+[a] then [k] then [y]
  • Disconnect the calculator
  • Close the Terminal application

Firmware update

  • Open the Terminal application
  • Connect the calculator
  • sudo lpc21isp -control -controlinv -hex DM16_21.hex /dev/tty.SLAB_USBtoUART 115200 12000
  • Push the reset button on the back of the calculator
  • When the upgrade is finished disconnect the calculator
  • Push the reset button on the back of the calculator
  • Close the Terminal application


Under Linux the procedure is very similar as under Windows, but instead the tool lpc21isp must be used in a console:

  • sudo apt-get install lpc21isp
  • sudo lpc21isp DM15_M1B_V29.hex /dev/ttyUSB0 115200 12000
  • press the RESET button after the message "Synchronizing (ESC to abort)" to initiate the upgrade process
  • after flash procedure is done, push the same "RESET" button again

Key Combinations

The Voyager series calculators have some special key combinations, some are the same as on the HP calculators, some are unique to SwissMicros calculators.

The location of the buttons is the same for all models, but the buttons might be labeled differently.


  1. Turn off calculator
  2. Press and hold one of the buttons listed below
  3. Press and release [ON] button
  4. Release first button pressed

Key Function Table

DM15 DM41 Function description
[A] [A] Display time/date for 5 minutes
[B] N/A Evaluate benchmark compared with orig. calc
[C] [C] Switch to serial console (see below)
[E] [E] Firmware version & battery voltage
[CHS] [CHS] Change LCD contrast with buttons [+], [-], [3], [Σ+]
[STO] [STO] Adjust RTC decrement -1h
[RCL] [RCL] Adjust RTC increment +1h
[7] N/A Cycle through available fonts
[9] [8] Toggle between 12MHz and 48MHz
[÷] [9] Keyboard self test
[⨯] N/A Self test
[-] N/A Power reset
[+] N/A Endless test
[.] N/A Toggle decimal delimiter
[SST] [x<>y] Time/date adjustment.
Use [/], [⨯], [-], [+] to change and [ENTER] to set

Serial Console

  • Put calculator in serial console mode by [C]+[ON]
  • Connect miniUSB cable to computer.
  • Drivers for many platforms including Win, MacOSX, Linux can be found here
  • Open terminal program; on windows putty (or hyperterm if you are brave enough), minicom under linux, use Terminal under MacOSX
  • For Linux/MacOSX find the device using "ls /dev/ttyUSB*" or "ls /dev/tty.S*" if you installed silab driver
  • Set terminal emulation program to 38400,8n1 (no flow control) (for example on Linux use "minicom /dev/tty.SLAB_USBtoUART 38400,8n1" or on MacOSX "screen /dev/tty.SLAB_USBtoUART 38400,8n1")
  • Encode and decode utility (html with jscript) for RAM save and restore function
  • A great HP-15C Simulator for Windows, Linux and Mac OS X supports data exchange with the DM15
  • Instructions for the serial console for Mac and Windows (PDF)

Battery Replacement

  • Turn calculator off; the content remains for about 30 seconds without battery
  • Unscrew all four screws
  • Remove calculator from case
  • Replace battery
  • Put it back together, don't tighten the screws too much

LCD Contrast

  • [CHS]+[ON] starts the LCD mode setting
  • Use [+], [-], [SUM+] and [3] to change the contrast


The models DM11, DM12, DM15 and DM16 include four font types: slim, bold, block and segmented. The combination [7]+[ON] cycles through all three font types.


SwissMicros believes that the user should have full control over the hardware. We provide an SDK to get you started with customization of the hardware to your needs.

Voyager series SDK can be downloaded here:

Differences to the original HP calculators

  • SwissMicros calculators are not in any way associated with the company HP.
  • They do not have all the bugs found in the HP-15C LE, see the bug list!
  • They run up to 30 times faster (at 48MHZ) than the original calculator introduced back in 80'
  • The USB connection features a command line interface for saving and restoring complete calculator state.
  • Encode and decode utility to save, edit and restore programs.
  • Firmware update through the miniUSB connection using the SwissMicros Firmware Update Tool.