------------------------------------------------------------------------------ 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 both tx and rx lengths are decremented together. The case where rx is longer than tx requires greater complexity to ensure all rx data is clocked in. See the adv example for this.