IRQ question about SPI as a slave

[Anonymous]

For our case, the SPI1 of the wiced module is used as a slave mode.

I have modified wiced_spi_init() to make SPI1 be a slave, and the data sent from master can be received correctly by polling SPI bus.

However, I would like to enable the IRQ of SPI1.

The IRQ is enabled by the following code due to STM32F2xx is used.

     SPI_I2S_ITConfig(spi_mapping[spi->port].spi_regs, SPI_I2S_IT_RXNE, ENABLE);

In addition, SPI1_irq() handler is implemented but this ISR is not called while data arriving.

Is there anything missed to enable the SPI IRQ?

Should link files be modified accordingly ?

[Anonymous · Accepted solution]

The reason is that I forget to configure NVIC for SPI IRQ.

No modification on link file is needed.

[Anonymous]

I have an issue which may be similar to your case. I am trying to implement SPI slave with transmit only. Clock will be provided by master (in this case I am just running a PWM and connecting it externally to the CLK pin of SPI).

I realized that wiced_spi_init and platform_spi_init functions did not provide the options for slave and single line. Made some modifications to allow for that.

Now I am stuck at spi_transfer function. When not using DMA, the code just gets stuck. And when using DMA, spi_dma_transfer function returns WICED_TIMEOUT.

What am I doing wrong? My application is a simple broadcaster at frequency provided by the clock (38kHz in this case). It can be used for IR communication (one-way, tx only like remotes).

I would really appreciate your help.

[Anonymous]

Hi,

I am assuming that slave is to receive data in your case.

Regarding using DMA mode,

you can increase the timeout value temporarily, that I ever tried it.

Then it should get the sent data from host.

[Anonymous]

The underlying platform is STM32F2xx, which does not support 38kHz clock for SPI.

I would like to transmit data, and since required speed is not supported by the platform, I decided that an external clock could be used and use SPI in slave mode to transmit data.

In platform_spi.c I made a new function which is similar to platform_spi_init but also allows to provide direction and master/slave setting. For example, following is set:

spi_init.SPI_Direction = SPI_Direction_1Line_Tx;

spi_init.SPI_Mode      = SPI_Mode_Slave;

After this

SPI_Cmd ( spi->port, ENABLE );

which SETs SPE in CR1 register to initialize the SPI.

I didn't modify the transfer functions and am trying to use the original ones. I am wondering if there is anything additional that needs to be taken care of when using SPI in slave mode.

[Anonymous]

DMA Timeout issue resolved for SPI Master mode.

Ref: SPI master and DMA, tested ?

(special thanks to gbrivet)

I will try to tackle the slave issues:

Trying to use the SPI in slave mode to transmit data (TX only) and there is an external clock (generated via wiced_pwm lib connected to CLK pin via jumper).

If suggestions, please share.

[Anonymous]

Hi,

Did you modify chip_select code in wiced_spi_init() as below ?

wiced_gpio_init(spi->chip_select, INPUT_HIGH_IMPEDANCE); //we are slave

[Anonymous]

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