Randy has alerted me of this post in Gimbal enhancement list · Issue #20985 · ArduPilot/ardupilot · GitHub, and if I didn’t got it wrong was asking for an opinion on STorM32 gimbals.
Sadly, the reality is that there is no thing like a STorM32 gimbal which could be purchased or would be available otherwise.
The listed HAKRC gimbal does indeed use a STorM32 controller, but its IMU is connected via the I2C bus, which was given up by the STorM32 project something like 5 or more years ago. That is, one only can run this gimbal with firmware version v0.96, which is said years old. One implication is, that its MAVlink capabilities is not up to date, and in fact is “incorrect”, as the whole comp_id thing wasn’t worked out on all sides at this time. To cut a long story short: I really cannot recommend this gimbal as-is for any effort to modernize gimbal drivers.
The minimum one would have to do, IMHO, in order to be able to use the latest STorM32 firmware, is to replace the I2C based IMU by an NT bus IMU, which implies some manual labour for the conversion. What is more serious is that there are essentially no good sources anymore for getting NT IMUs … the Corona & chip crisis appear to have been kind of last nail in the coffin. ENSYS lists some as available, STorM32 NT IMU Module v3.0 – ENSYS. Gapey builds on demand, but I’m not sure he still does or is able to (we have a war since few months in Europe) Assembled PCB Storm32 / T-Storm32 - Сайт t-storm32!.
To make it even worse, one also has to face the fact that - in my observation - the v1.3x type controllers on the market, which is also on the HAKRC gimbal, started to lack quality. It kind of appears that all stuff which wouldn’t had been sold few years back are now cleared out at all costs.
I guess I don’t have to find words for a summary. My conclusion is probably self-explanatory.
Even though it’s already a very long text, I’d like to grab the opportunity for exposing what I think could be an approach to this situation.
The STorM32 serial driver could be with little changes updated to work also with later firmware versions (at least I think so … 5 years is a lot time to lose memory of details LOL). There are indeed still users of I2C based STorM32 gimbals, so some minimum support might be appreciated.
The current MAVLink-based STorM32 driver could be replaced by a generic MAVLink gimbal driver, which can be designed such as to work with any MAVLink enabled gimbal, specifically Gremsy, Alexmos, STorM32. It could be resulting from overlapping of what is currently there for Gremsy and STorM32 in the BetaPilot fork.
I find it important to add, that, since STorM32 still sees development (at varying pace), I would not think that an extra STorM32-Mavlink gimbal driver is reasonable. I try to keep the BetaPilot somewhat up-to-date, and anyone serious with STorM32 can use this. I thus would think that the mentioned generic MAVLink gimbal driver should be indeed generic, which IMHO implies that it should conform to some standard, which all parties can settle for.
Not sure this is very helpful, and sorry for the long text,