Hi,
We'd recommend the OSTC nano for this. It has the same screen size as the OSTC 3, a very robust housing and overall design. In the TECH Version you get all the features you need and we see the OSTC nano beeing used as a CCR backup quite often now.
https://hwdiving.com/produkt/ostc-nano/?lang ...
Search found 4486 matches
- 21 Aug 2026, 12:34
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: Replacement suggestion as my OSTC3 finally died on me
- Replies: 1
- Views: 180
- 10 Jul 2026, 15:59
- Forum: OSTC 4 and OSTC 5
- Topic: hwOS4: New Firmware 1.7.6 beta with new Compass
- Replies: 0
- Views: 1974
hwOS4: New Firmware 1.7.6 beta with new Compass
Hi all,
Attached to this mail is the new 1.7.6 beta firmware for all OSTC 4 and OSTC 5 users. This version has, among many smaller changes and fixes, the new compass design for everybody to test. The new compass is highly configurable in the menu ("Compass Style" - this menu is accessible during ...
Attached to this mail is the new 1.7.6 beta firmware for all OSTC 4 and OSTC 5 users. This version has, among many smaller changes and fixes, the new compass design for everybody to test. The new compass is highly configurable in the menu ("Compass Style" - this menu is accessible during ...
- 22 Jun 2026, 12:57
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: Firmware update 10.97 Problem beim OSTC Sport
- Replies: 8
- Views: 1719
Re: Firmware update 10.97 Problem beim OSTC Sport
Hallo,
Die Firmware 10.97 läuft erst, wenn sie installiert wurde. Die hat zumindest mal mit dem Updateproblem hier absolut nichts zu tun. Schicke den OSTC im Zweifelsfall zu uns, wir bekommen das schon installiert.
Gruß,
Matthias
Die Firmware 10.97 läuft erst, wenn sie installiert wurde. Die hat zumindest mal mit dem Updateproblem hier absolut nichts zu tun. Schicke den OSTC im Zweifelsfall zu uns, wir bekommen das schon installiert.
Gruß,
Matthias
- 15 Jun 2026, 15:48
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: Firmware update 10.97 Problem beim OSTC Sport
- Replies: 8
- Views: 1719
Re: Firmware update 10.97 Problem beim OSTC Sport
Bei "OSTConf" (Der iPhone App, die Du vermutlich meinst) geht nur BLE. Hier mal im OSTC reset menü ein "Reset-Bluetooth" auswählen.
Gruß,
Matthias
Gruß,
Matthias
- 12 Jun 2026, 19:00
- Forum: OSTC Mk.2, 2N and 2C (Sold between 2007 and 2014)
- Topic: OSTC Mk2 Screen staying dark
- Replies: 4
- Views: 1761
Re: OSTC Mk2 Screen staying dark
I agree, this looks like the unit is end-of-life unfortunately.
Matthias
Matthias
- 11 Jun 2026, 11:09
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: Firmware update 10.97 Problem beim OSTC Sport
- Replies: 8
- Views: 1719
Re: Firmware update 10.97 Problem beim OSTC Sport
Hallo,
Einfach nochmal anstoßen, das Update. Vielleicht mal mit Bluetooth Classis statt BLE oder umgekehrt.
Gruß,
Matthias
Einfach nochmal anstoßen, das Update. Vielleicht mal mit Bluetooth Classis statt BLE oder umgekehrt.
Gruß,
Matthias
- 11 Jun 2026, 11:08
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: OSTC 2 hwOS tech
- Replies: 7
- Views: 7907
Re: OSTC 2 hwOS tech
Vielleicht wäre in dem Fall ein OSTC+ die bessere Wahl, da kann man die AA Batterie einfach selber tauschen.
Gruß,
Matthias
Gruß,
Matthias
- 10 Jun 2026, 22:07
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: OSTC 2 hwOS tech
- Replies: 7
- Views: 7907
Re: OSTC 2 hwOS tech
Und warum das so implementiert wurde haben wir ja schon einen Beitrag weiter oben beschrieben. Das dient dem Schutz der Batteriezelle, welche im OSTC 2 schon seit sehr vielen Jahren aus guten Gründen fest verbaut ist.
- 31 May 2026, 16:54
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS TECH: New Firmware 3.33
- Replies: 29
- Views: 180703
Re: hwOS TECH: New Firmware 3.33
Continue here: viewtopic.php?t=22724
- 31 May 2026, 16:54
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS TECH: New Firmware 3.37
- Replies: 0
- Views: 2235
hwOS TECH: New Firmware 3.37
Hello,
ENGLISH:
The new hwOS tech firmware 3.37 is now available for download:
https://hwdiving.com/firmware/?lang=en
Using OSTC+ or OSTC cR with external O2-Monitoring? Make sure to install the firmware with "_cr_" in the file name to keep the O2-Monitoring option available!
[3.37]
MD5 ...
ENGLISH:
The new hwOS tech firmware 3.37 is now available for download:
https://hwdiving.com/firmware/?lang=en
Using OSTC+ or OSTC cR with external O2-Monitoring? Make sure to install the firmware with "_cr_" in the file name to keep the O2-Monitoring option available!
[3.37]
MD5 ...
- 24 May 2026, 16:23
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS Sport: New Firmware 10.97
- Replies: 0
- Views: 3477
hwOS Sport: New Firmware 10.97
Hello,
The new hwOS sport firmware 10.97 is now available for download:
https://hwdiving.com/firmware/?lang=en
The following changes have been applied:
[10.97]
MD5: 57dd4b6843bef9c0a6a77dbec182eb5d
NEW: Add color-coded battery voltage as an additional warning for a low battery (3,6V rechargeable ...
The new hwOS sport firmware 10.97 is now available for download:
https://hwdiving.com/firmware/?lang=en
The following changes have been applied:
[10.97]
MD5: 57dd4b6843bef9c0a6a77dbec182eb5d
NEW: Add color-coded battery voltage as an additional warning for a low battery (3,6V rechargeable ...
- 16 May 2026, 16:19
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: OSTC Sport Firmware announcement
- Replies: 1
- Views: 19843
Re: OSTC Sport Firmware announcement
Hallo,
Das machen wir auch hier weiterhin so. Allerdings waren die letzten Versionen nur für die neuen OSTC+ Versionen nötig und sind funktional unverändert. Bei für alle Versionen empfohlenen Updates machen wir das in Zukunft wieder.
Gruß,
Matthias
Das machen wir auch hier weiterhin so. Allerdings waren die letzten Versionen nur für die neuen OSTC+ Versionen nötig und sind funktional unverändert. Bei für alle Versionen empfohlenen Updates machen wir das in Zukunft wieder.
Gruß,
Matthias
- 12 Apr 2026, 13:16
- Forum: OSTC Mk.2, 2N and 2C (Sold between 2007 and 2014)
- Topic: New 3.16 Firmware
- Replies: 4
- Views: 146645
Re: New 3.16 Firmware
There are no known issues with this 3.16, so update to 3.16 and I'm sure it will work fine with your 2C then.
Matthias
Matthias
- 09 Apr 2026, 12:47
- Forum: OSTC Mk.2, 2N and 2C (Sold between 2007 and 2014)
- Topic: New 3.16 Firmware
- Replies: 4
- Views: 146645
Re: New 3.16 Firmware
Hello,
This is a bit tricky, but you can restore it using the ^‘Bootloader v1’ on Windows: https://forum.heinrichsweikamp.com/viewtopic.php?t=4071
> If firmware version <1.90 is still installed:
> - Download Bootloader v1
> - Select OSTC, Mk.2/2N/2C
> - Click on ‘Update Firmware’
> - Select the ...
This is a bit tricky, but you can restore it using the ^‘Bootloader v1’ on Windows: https://forum.heinrichsweikamp.com/viewtopic.php?t=4071
> If firmware version <1.90 is still installed:
> - Download Bootloader v1
> - Select OSTC, Mk.2/2N/2C
> - Click on ‘Update Firmware’
> - Select the ...
- 09 Apr 2026, 10:22
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: Using Subsurface to update BLE-only OSTC
- Replies: 0
- Views: 18885
Using Subsurface to update BLE-only OSTC
The newer OSTC+ (2026 and later) and OSTC Nano models require a Bluetooth Low Energy (BLE)-compatible updater to update the firmware. While the OSTConf iOS app or the latest HWOS Config for Android can perform this task on your mobile device, the old OSTC Companion is unable to do so on desktop ...
- 28 Mar 2026, 20:02
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS TECH: New Firmware 3.33
- Replies: 29
- Views: 180703
Re: hwOS TECH: New Firmware 3.33
fixed in the 3.34...
[3.34]
BUGFIX: Compass showed 000 when dive mode was started out of sleep mode
NEW: Support for new hardware versions (OSTC+ only)
BUGFIX: String "Höhle" was not properly shown (German version only)
BUGFIX: Digital S8 Interface could delay startup on OSTC+ S8 in rare caes
[3.34]
BUGFIX: Compass showed 000 when dive mode was started out of sleep mode
NEW: Support for new hardware versions (OSTC+ only)
BUGFIX: String "Höhle" was not properly shown (German version only)
BUGFIX: Digital S8 Interface could delay startup on OSTC+ S8 in rare caes
- 27 Mar 2026, 09:16
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: comparison 2, nano or +?
- Replies: 3
- Views: 13326
Re: comparison 2, nano or +?
The battery compartment in the OSTC+ and the USB port in the OSTC nano are watertight. This is fine for a small leak or in freshwater, but if you dive a week-long liveaboard with a leaking battery cap or missing USB cap, both units will suffer damage.
Regards,
Matthias
Regards,
Matthias
- 23 Mar 2026, 20:51
- Forum: OSTC 4 and OSTC 5
- Topic: hwOS4: New Firmware 1.7.5 with RTE 3.70
- Replies: 10
- Views: 46309
Re: hwOS4: New Firmware 1.7.5 with RTE 3.70
Yes, in bailout mode the OSTC 4 usues normal OC calculations for decompression and ppO2 warnings.
- 22 Mar 2026, 17:34
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: comparison 2, nano or +?
- Replies: 3
- Views: 13326
Re: comparison 2, nano or +?
Hi,
I have our comparison sheet attached here. If you don't mind the slightly smaller display, the OSTC nano is very popular right now. Especially for CCR divers (as a backup with fixed setpoints).
Regards,
Matthias
I have our comparison sheet attached here. If you don't mind the slightly smaller display, the OSTC nano is very popular right now. Especially for CCR divers (as a backup with fixed setpoints).
Regards,
Matthias
- 25 Feb 2026, 16:06
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS TECH: New Firmware 3.33
- Replies: 29
- Views: 180703
Re: hwOS TECH: New Firmware 3.33
Die Kompass-Anzeige tut da wieder so, egal ob der OSTC beim abtauchen an ist, oder nicht.
Gruß,
Matthias
Gruß,
Matthias
- 13 Feb 2026, 17:01
- Forum: OSTC 4 and OSTC 5
- Topic: hwOS4: New Firmware 1.7.5 with RTE 3.70
- Replies: 10
- Views: 46309
Re: hwOS4: New Firmware 1.7.5 with RTE 3.70
We have this in the code already: https://code.heinrichsweikamp.com/publi ... 73180fde1d
It wasn't added to the latest release because we have not tested it in detail yet (Tests with the logbook software/Apps).
regards,
Matthias
It wasn't added to the latest release because we have not tested it in detail yet (Tests with the logbook software/Apps).
regards,
Matthias
- 03 Feb 2026, 10:14
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS TECH: New Firmware 3.33
- Replies: 29
- Views: 180703
Re: hwOS TECH: New Firmware 3.33
Von welcher Version bist Du denn gekommen? Stelle zudem noch den Batterietyp auf T3 (Reset menü). T0 stimmt für den OSTC cR nicht.
Gruß,
matthias
Gruß,
matthias
- 02 Feb 2026, 09:35
- Forum: OSTC+, 3, cR, sport, nano and OSTC 2 (Mod. 2015 and later)
- Topic: hwOS TECH: New Firmware 3.33
- Replies: 29
- Views: 180703
Re: hwOS TECH: New Firmware 3.33
We updated this post for the 3.33 release. Many thanks to everyone who provided detailed and helpful information about this issue. This enabled us to quickly narrow down the problem.
- 02 Feb 2026, 09:15
- Forum: OSTC Mk.2, 2N and 2C (Sold between 2007 and 2014)
- Topic: OSTC Mk.2, 2N or 2C Firmware Update - HowTo
- Replies: 6
- Views: 70568
Re: OSTC Mk.2, 2N or 2C Firmware Update - HowTo
We updated the links in the post above: https://hwdiving.com/firmware/?lang=en
- 12 Jan 2026, 18:31
- Forum: OSTC 4 and OSTC 5
- Topic: hwOS4: New Firmware 1.7.5 with RTE 3.70
- Replies: 10
- Views: 46309
hwOS4: New Firmware 1.7.5 with RTE 3.70
ENGLISH below.
Hallo,
Die neue Firmware 1.7.5 wurde nun veröffentlicht.
Firmwares
Anleitung zur Installation: https://forum.heinrichsweikamp.com/viewtopic.php?f=7&t=19186 (Je nach aktueller Version kann es nötig sein, das Update zweimal zu starten. Der OSTC4 bzw. OSTC 5 gibt dazu nach dem ...
Hallo,
Die neue Firmware 1.7.5 wurde nun veröffentlicht.
Firmwares
Anleitung zur Installation: https://forum.heinrichsweikamp.com/viewtopic.php?f=7&t=19186 (Je nach aktueller Version kann es nötig sein, das Update zweimal zu starten. Der OSTC4 bzw. OSTC 5 gibt dazu nach dem ...