I’ve shipped test build 345 onto TestFlight this evening.

This build supports MS1, MS1/Extra and MS2/Extra having been tested against my own ECUs.

MS2 testing has revealed a weakness of the Bluetooth interface, compared to WiFi and I’m still investigating ways around it. For the moment though I’ve put a workaround into the app to compensate. It does mean though that it’s unlikely that the same Bluetooth device that you use for iOS can be used for TunerStudio or similar.

There is a limitation in some of the modules that prevents the module transmitting a block of data that’s more than 500 bytes long at 115,200 baud. For MS2 and MS2/Extra this is an issue as the data pages that the app loads at startup are 1024 bytes each. This certainly applies to the HC-08 modules and I will test the HM-10 module, hopefully, in the next couple of evenings to see if that has the same limitation.

In preparation for initial testing of the new app, the user manual section of the web site has been updated with details of the new functionality.

In addition, I’ve added a guide to building a Bluetooth connector and using it which, hopefully, will allow more meaningful testing. For anyone not confident to build their own, I have had preliminary talks with a company that may be able to supply a completed solution “plug and play”.

Connecting via Bluetooth

This is a short video/screen recording of a very early Bluetooth enabled version of the app. Still a way to go before it’s ready for testing but as it stands it’s a promising basis for the new app.
The ECU is connected to a simulator so the realtime data may look a bit odd as I swing the inputs around to test the response.
The sampling throughput is running at a steady 11 samples per second which is a bit down on the WiFi adaptor but more than adequate for most uses.
Now I know that the Bluetooth adapter works and is reliable I’ll put together a “how to” guide, showing what is needed to build the interface.
A test version of the app will be released to testers, probably within a week or so. I have some UI glitches to fix now the basic connectivity is working.

As a spin off from another project that I’ve been working on which uses a Bluetooth module to transfer data between an MCU and an iPhone, I’ve been mulling over the amount of work required to both update the MobiSquirt app to the current architecture (to get it back on the app store) and, at the same time add in support for Bluetooth. It can then be added back onto the app store.

To gauge interest and support for the project I’ll be looking for beta testers in the next month or so. If you have already expressed an interest in testing the app I will send you a TestFlight invitation and you will then be notified as soon as a new build is available for testing.

The cost for the Bluetooth components is around £15 from Amazon, cheaper if you get them from AliExpress or similar. I now have this link working in another project and, hopefully, transferring the code across shouldn’t be too painful.

I’ll post a further update when I have a better idea of the work involved and time scales. It won’t happen overnight and is likely to take months rather than days as I fit it in between my other time commitments but after a break from the project I’m now feeling more enthused about it. 

Things are moving on gradually…

I’ve fixed all the problems with the architecture of the app and it’s now working as fast as a PC connected via a serial cable when it comes to creating log files, in the region of 16 lines per second on an MS1/Extra. I have 2 more screens to update to iOS7+ compatible and I’ll be looking, finally, at a release. The new architecture has opened up a number of possibilities as well as removing many of the stumbling blocks that were limiting it’s performance.

One of the more recent problems being experienced is a practical one since MicroChip bought out Roving Networks and pulled the rug out from underneath the simplest and cheapest connection option. Obviously one solution to this has been to start looking at BlueTooth interfaces but in tandem to that I’ve also been looking at a much lower cost WiFi option that uses a couple of “off the shelf” modules hooked together. Initial results have been good and it would bring the cost of a WiFi adaptor down to less than £12 ($15USD) but it will need to be flashed with some simple custom code that I’m going to release as an open source project. The software to compile and upload the software to the module is free and you just need a USB cable to flash the module.

This is actually a much better solution than the RN134 as it offers a secure, password protected, connection and a customisable web interface to configure it and, being so much cheaper, will be a good option.

I may be adding banner advertising to the app in an attempt to help it pay for itself. Although the donation model worked initially it’s not covered the costs of developing the app or hosting this web site, let alone the cost of MegaSquirt ECUs to test against. Banner advertising has proved reasonably successful in my other apps as a way of generating a small but steady revenue that might, at least, help offset some of the costs.

The second test version of MobiSquirt has been made available to testers with fixes for a couple of bugs that were found.

A couple of things came out of a request on the forum, one of which resulted in the addition of an email facility so that log files can be emailed directly from the app to make it more convenient to transfer the log files. As this was a comparatively minor amount of work this was implemented in the new test version.

Another aspect of the post was the question of security of the MegaSquirt once you have a WiFi connection to it, particularly as the WiFly unit doesn’t offer support for encryption for Ad Hoc connections. It does, however, offer a password option of up to 32 characters long which you can enter into the module. Any connection to the module is then dropped if the host doesn’t supply that password immediately on connecting. This actually tied quite neatly into another development I’ve been working for both testing and app approval reasons – a demo server. Having a similar password requirement for that should minimise the amount of spurious connections the server would have to handle.

To that end the next test version will support the WiFly modules’ password option as I can then build the same password function into the demo server. the bulk of the development required in MobiSquirt for this has now been done and been tested locally.

Thanks to those who have volunteered to test the app and given feedback, keep those ideas coming !