+ LED_A_OFF();
+ cmd_send(CMD_ACK,0,0,0,0,0);
+}
+/*
+Reading a COTAG.
+
+COTAG needs the reader to send a startsequence and the card has an extreme slow datarate.
+because of this, we can "sample" the data signal but we interpreate it to Manchester direct.
+
+READER START SEQUENCE:
+burst 800 us, gap 2.2 msecs
+burst 3.6 msecs gap 2.2 msecs
+burst 800 us gap 2.2 msecs
+pulse 3.6 msecs
+
+This triggers a COTAG tag to response
+*/
+void Cotag(uint32_t arg0) {
+
+#define OFF { FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); WaitUS(2035); }
+#define ON(x) { FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD); WaitUS((x)); }
+
+ uint8_t rawsignal = arg0 & 0xF;
+
+ LED_A_ON();
+
+ // Switching to LF image on FPGA. This might empty BigBuff
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+ //clear buffer now so it does not interfere with timing later
+ BigBuf_Clear_ext(false);
+
+ // Set up FPGA, 132kHz to power up the tag
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 89);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+ // Connect the A/D to the peak-detected low-frequency path.
+ SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+
+ // Now set up the SSC to get the ADC samples that are now streaming at us.
+ FpgaSetupSsc();
+
+ // start clock - 1.5ticks is 1us
+ StartTicks();
+
+ //send COTAG start pulse
+ ON(740) OFF
+ ON(3330) OFF
+ ON(740) OFF
+ ON(1000)
+
+ switch(rawsignal) {
+ case 0: doCotagAcquisition(50000); break;
+ case 1: doCotagAcquisitionManchester(); break;
+ case 2: DoAcquisition_config(TRUE); break;
+ }
+
+ // Turn the field off
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ cmd_send(CMD_ACK,0,0,0,0,0);
+ LED_A_OFF();