Hi all,
I’m currently trying to port the SPP app from LM3S9B96 to the eval bot.There are some problems coming with this:
- - The reset signal pin changes- RX and TX pin of UART1 changes- The slow clock 32.768 Hz signal is not connect to the controller- RTS and CTS pins of UART1 are not switchable to the right pins
The first and second one are pretty simple to solve. The third one can be handled by making a connection from PE7 to TP21 (TP21 is connected to the slow clock pin of the BT-module) and using a PWM with 32.768 Hz and a duty cycle of 50 %. Redirecting the RTS and CTS pins can be handled by an ISR which transfers the pin states to the right one (here connections from PJ2 to PJ3 and PJ5 to PJ6).
That are the hard and software changes that are needed. They will work and react as expected. However the BT initialization will fail. Measurements shows that the BT-Module will never change the state of its RTS pin and will not answer on its UART TX pin.
The attached diagram shows the modifications. Colors of labels and connections means the following: green ones are unchanged, red ones are completely new and violate ones are changed.
SSI1 and I2C0 is not touched in anyway.
However, I don’t get any signal on the BT-UART-TX pin. Also its RTS pin will never change. Can someone say me what is missing. If some informations are missing, don't hesitate to contact me.
Thanks and best Regards,
Frank
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Frank,
1) Using a PWM might not be a good idea given that the 32kHz clock needs to have a max 250ppm deviation
2) What's the state of the CTS pin? It should be low.
I don't see a diagram attached. It would be helpful to see it.
Regards,
Gustavo
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Hello Gustavo,
thanks for replying.
1) Okay, seems I need to use another clocksignal.
2) The CTS pin is always high.
Now the diagram is attached.
Best regards,
Please note that our reference platform uses an external oscillator on the EM2 board to supply the SLOW CLK to the PAN13xx module.
Also, keep in mind that the PAN13xx requires UART HW flow control.
~Miguel
Hello Miguel,
I have already checked this. I'm currently designing an adapter PCB for the eval bot to make it possible to run the BT module. It contains only the oscillator, some capacitors and plugs.
However, does someone know the reason why there is no 32.768 kHz osc on the PAN13xxETUs? It would absolutly be easier if these were driectly on the board.
The main reason is because in other Platforms (e.g. MSP430 as the host) the Slow Clock can be supplied by the Host. Therefore, it becomes optional. In the case of Stellaris, it cannot supply such clock.