731 B
731 B
README
This example program demonstrates SPI transceive with DMA on [Lisa/M 2.0 board](http://paparazzi.enac.fr/wiki/Lisa/M_v20 for details).
The terminal settings for the receiving device/PC are 9600 8n1.
The example expects a loopback connection between the MISO and MOSI pins on SPI1. The DRDY and SS pins (on the Lisa/M v2.0 SPI1 connector) are used as GPIO to time the tx and rx ISRs, respectively. Use a scope or logic analyzer.
The tx length is incremented, followed by the rx length, after which the tx is decremented, then the rx is decremented. This is repeated in a loop. In this example, rx lengths longer than tx lengths are handled by using two dma transmits one after the other, handled inside the tx dma ISR.