RoseOnRails – the global architecture


This morning, I did a plan to summarize the architecture of our system.


RoseOnRails – Global architecture

Then I started to work on BLE again. So borrowed MarcO’s board and… of course the app worked fine…. almost! The connection with gatttool was successful and didn’t get interrupted accidentally after a second or so (like it did on my board). However, I couldn’t manage to change the characteristic’s value. Matthieu said he managed on Nexus 4 so I guess the problem doesn’t come from the code. But I don’t yet see what the problem could be?? Gatttool maybe? Anyway, I have to make it work on Linux (for now it’s in command line but we’ll eventually use BlueLib to code the whole app) since our Central Station will be on a PC.

In the afternoon, Gleison and I carried out some experiments to determine how we were going to provide the alimentation for the railroads. In fact, we found out that the current alimentation system (that is, with the booster and the DCC remote control), isn’t relevant for our system (since of course we won’t be using DCC anymore). The problem (actually it’s not a real problem..) is that the tranfomers don’t do the rectification from AC to DC. Therefore, we’ll have to insert a cicuit (diod bridge + capacitors) to convert the AC signal to DC before providing the alimentation to the railroad.

Tonight, in order for me to be able to go further in the simulation of the motor woth Simulink (to determine the PWM frequency), Gleison and I carried out some experiments to determine the inductance of the motor. We first measured its resistance then the inductance. However, unfortunately, we obtained some incoherent results for the inductance. More precisely, we did’nt find the same values when we tried different methods (for the resistance… but since the inductance was calculated based on the resistance, the inductance value we obtained wasn’t relaibale either of course). We will re-do it tomorrow to find out what went wrong…

See you soon.


3 comments to RoseOnRails – the global architecture

  • As I asked another team, do you really need an STM32 + nRF51822 on a same board? (the LED board)
    …maybe the nRF8001 will suffice 😉
    Nice schema!

  • valeh

    Well, the thing is that we’re using the WS2812B led strips. These require a very precise timing to be correctly controlled, and the nrf51822 is very often interrupted because of the BLE stack events. That’s basically the reason why we’ve decided to use another uC (the STM32 in this case).

  • OK, thanks for the answer 😉