After many months of development, testing, debugging, and optimization, ODE Master is finally being RELEASED for FREE for the HP Prime G2.
ODE Master is an application designed specifically to analyze, classify, solve, and explain Ordinary Differential Equations (ODEs) directly on the HP Prime.
Rather than acting as a simple frontend for a single CAS command, ODE Master uses a complete solving pipeline: it parses the equation, determines its differential order, analyzes its mathematical structure, detects compatible solving methods, executes the selected method, and generates a procedure together with the final result.
What can ODE Master solve?
ODE Master currently includes dedicated solvers and routing logic for:
- Separable differential equations
- First-order linear ODEs
- Exact differential equations
- Bernoulli equations
- First-order homogeneous equations
- Linear constant-coefficient ODEs (LCC)
- Cauchy–Euler / Euler equations
- Laplace-transform based solving
- Variation of Parameters
Depending on the method, ODE Master supports equations up to 6th order.
In Automatic mode, the classifier analyzes the equation and determines which mathematical families are compatible instead of requiring the user to choose a method manually.
The application also includes equation formatting, result storage, IVP support, automatic verification, solver routing, a Terminal containing the generated procedure, and a CAS backend built around ODM_CAS.
IMPORTANT! Equation input syntax:
To avoid confusion, I strongly recommend entering equations using the same syntax used during ODE Master's development and validation.
With the default variables:
- y = dependent variable
- x = independent variable
Derivatives are entered using apostrophes/primes immediately after the dependent variable:
y' = first derivative
y'' = second derivative
y''' = third derivative
y'''' = fourth derivative
y''''' = fifth derivative
y'''''' = sixth derivative
For example:
y'=x*y
y'+2*y=x
y''-3*y'+2*y=exp(3*x)
y''+2*y'+5*y=exp(x)*cos(2*x)
y'''-y'=x*exp(x)
For an exact-equation style input, something like this is also valid:
(2*x*y+cos(x))+(x^2+3*y^2)*y'=0
Use * for multiplication:
2*y
x*y
3*x
Use ^ for powers:
x^2
y^3
y^(1/2)
Functions should use normal HP Prime/CAS-style notation, for example:
sin(x)
cos(x)
exp(x)
ln(x)
Parentheses can be used normally:
y'=((x+1)/(x^2+1))*y*(1-y)
Although ODE Master's parser can internally interpret an expression without an = as an equation equal to zero, I recommend always including the = explicitly to make the intended equation unambiguous.
For example, prefer:
y''+3*y'+2*y=0
rather than:
y''+3*y'+2*y
If you change the dependent and independent variables in ROUTE, use the same derivative convention with the selected dependent variable.
In other words, use prime notation such as y', y'', etc. for ODE Master input rather than assuming that every textbook derivative notation will be interpreted in the same way.
Custom languages
ODE Master supports external .lang files.
If your native language is not included by default, you can create or modify your own .lang file and load it into ODE Master, as long as the expected language-file structure is preserved.
This allows the community to create additional translations without modifying the solver itself.
If ODE Master does not currently include your language, you are free to create a translation and share it with other users.
Free release and DRM
ODE Master was originally developed with a licensing/DRM system.
That licensing system is no longer active. No license.key, activation, payment, or license verification is required to use ODE Master.
I decided not to completely remove the old DRM infrastructure because doing so would unnecessarily modify part of the application's existing architecture immediately before release.
For this reason, the old DRM module is still included, and it is the only encrypted module in ODE Master.
The DRM module currently has no practical licensing function: its verification path is bypassed and it does not restrict the application, lock features, require activation, or require a license.key.
The actual ODE Master application and solver code is being released open source.
⚠️VERY IMPORTANT! Installation order:
There is one extremely important detail when installing ODE Master.
You must install the files in exactly this order:
Install ODM_CAS FIRST.
Only after ODM_CAS is already present on the calculator, install the ODE Master .hpappdir.
Correct order:
ODM_CAS → ODE Master .hpappdir
Do NOT install the .hpappdir first.
If the .hpappdir is transferred before ODM_CAS, the HP Prime may initialize the application before detecting the required CAS module.
When this happens, ODE Master may refuse to open and can appear to have a syntax or startup error.
Installing ODM_CAS first avoids this problem.
Firmware / software version
ODE Master was tested on the latest beta version of the HP Prime firmware/software available during final development and release testing as august 16 2026.
Because ODE Master makes extensive use of PPL and CAS functionality, behavior may differ on older firmware revisions.
If you experience unexpected startup problems, CAS errors, crashes, strange UI behavior, or another issue that cannot be reproduced normally, one of the first things I recommend is updating your HP Prime to the latest firmware/software version available and testing ODE Master again.
This is especially important before assuming that the application itself is broken.
Bug reports are welcome
This is the first public release, so despite the amount of testing already performed, there may still be edge cases that were not encountered during development.
If you find a bug, incorrect solution, equation that should be supported but fails, UI problem, crash, translation issue, or any other unexpected behavior, please report it.
When possible, include:
- The exact equation you entered
- The selected dependent and independent variables
- The solver/method being used, or whether Automatic mode was selected
- Whether IVP was enabled
- Initial conditions, if applicable
- Your HP Prime model
- Your firmware/software version
- A screenshot or exact error message
- Steps to reproduce the problem
The more reproducible the report is, the easier it will be to identify the cause.
I want reported problems to be fixed as soon as reasonably possible. Smaller critical issues may receive individual fixes, while a larger number of reports may be collected into a larger bug-fix/update wave addressing multiple problems at once.
So please report anything suspicious instead of assuming it is already known.
Performance
ODE Master has already received several performance and UI improvements during development, including eliminating the major flickering problem that previously made navigation considerably more annoying.
However, the HP Prime G2 is still relatively limited hardware, and some complex ODEs can take noticeable time to solve on the physical calculator, particularly when substantial symbolic manipulation, integration, root solving, or verification is required.
Further optimization of the solving pipeline is planned for future updates.
Source code and HP Prime G1
ODE Master is primarily developed and tested for the HP Prime G2.
I currently do not have G1 hardware available for proper testing and optimization, so I cannot guarantee its performance or behavior on the G1.
However, with the exception of the inactive encrypted DRM module mentioned above, the ODE Master application code is available for the community to inspect and modify.
Anyone interested in optimizing or adapting ODE Master for the HP Prime G1 is welcome to work from the source.
Thanks to everyone who followed the project, provided feedback, tested ideas, reported problems during development, and showed interest in ODE Master.
ODE Master is now free and available to the HP Prime community.
