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Dependents:   mbed-TFT-example-NCS36510 mbed-Accelerometer-example-NCS36510 mbed-Accelerometer-example-NCS36510

features/unsupported/tests/mbed/modserial/main.cpp@0:098463de4c5d, 2017-01-25 (annotated)

Committer:
group-onsemi
Date:
Wed Jan 25 20:34:15 2017 +0000
Revision:
0:098463de4c5d
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
group-onsemi 0:098463de4c5d 1 /*
group-onsemi 0:098463de4c5d 2 * To run this test program, link p9 to p10 so the Serial loops
group-onsemi 0:098463de4c5d 3 * back and receives characters it sends.
group-onsemi 0:098463de4c5d 4 */
group-onsemi 0:098463de4c5d 5 #include "mbed.h"
group-onsemi 0:098463de4c5d 6 #include "MODSERIAL.h"
group-onsemi 0:098463de4c5d 7
group-onsemi 0:098463de4c5d 8 DigitalOut led1(LED1);
group-onsemi 0:098463de4c5d 9 DigitalOut led2(LED2);
group-onsemi 0:098463de4c5d 10 DigitalOut led3(LED3);
group-onsemi 0:098463de4c5d 11 DigitalOut led4(LED4);
group-onsemi 0:098463de4c5d 12
group-onsemi 0:098463de4c5d 13 MODSERIAL pc(USBTX, USBRX);
group-onsemi 0:098463de4c5d 14
group-onsemi 0:098463de4c5d 15 /*
group-onsemi 0:098463de4c5d 16 * As experiement, you can define MODSERIAL as show here and see what
group-onsemi 0:098463de4c5d 17 * effects it has on the LEDs.
group-onsemi 0:098463de4c5d 18 *
group-onsemi 0:098463de4c5d 19 * MODSERIAL uart(TX_PIN, RX_PIN, 512);
group-onsemi 0:098463de4c5d 20 * With this, the 512 characters sent can straight into the buffer
group-onsemi 0:098463de4c5d 21 * vary quickly. This means LED1 is only on briefly as the TX buffer
group-onsemi 0:098463de4c5d 22 * fills.
group-onsemi 0:098463de4c5d 23 *
group-onsemi 0:098463de4c5d 24 * MODSERIAL uart(TX_PIN, RX_PIN, 32);
group-onsemi 0:098463de4c5d 25 * With this, the buffer is smaller than the default 256 bytes and
group-onsemi 0:098463de4c5d 26 * therefore LED1 stays on much longer while the system waits for
group-onsemi 0:098463de4c5d 27 * room in the TX buffer.
group-onsemi 0:098463de4c5d 28 */
group-onsemi 0:098463de4c5d 29 MODSERIAL uart(p9, p10);
group-onsemi 0:098463de4c5d 30
group-onsemi 0:098463de4c5d 31 // This function is called when a character goes from the TX buffer
group-onsemi 0:098463de4c5d 32 // to the Uart THR FIFO register.
group-onsemi 0:098463de4c5d 33 void txCallback(MODSERIAL_IRQ_INFO *q) {
group-onsemi 0:098463de4c5d 34 led2 = !led2;
group-onsemi 0:098463de4c5d 35 }
group-onsemi 0:098463de4c5d 36
group-onsemi 0:098463de4c5d 37 // This function is called when TX buffer goes empty
group-onsemi 0:098463de4c5d 38 void txEmpty(MODSERIAL_IRQ_INFO *q) {
group-onsemi 0:098463de4c5d 39 led2 = 0;
group-onsemi 0:098463de4c5d 40 pc.puts(" Done. ");
group-onsemi 0:098463de4c5d 41 }
group-onsemi 0:098463de4c5d 42
group-onsemi 0:098463de4c5d 43 // This function is called when a character goes into the RX buffer.
group-onsemi 0:098463de4c5d 44 void rxCallback(MODSERIAL_IRQ_INFO *q) {
group-onsemi 0:098463de4c5d 45 led3 = !led3;
group-onsemi 0:098463de4c5d 46 pc.putc(uart.getc());
group-onsemi 0:098463de4c5d 47 }
group-onsemi 0:098463de4c5d 48
group-onsemi 0:098463de4c5d 49 int main() {
group-onsemi 0:098463de4c5d 50 int c = 'A';
group-onsemi 0:098463de4c5d 51
group-onsemi 0:098463de4c5d 52 // Ensure the baud rate for the PC "USB" serial is much
group-onsemi 0:098463de4c5d 53 // higher than "uart" baud rate below. (default: 9600)
group-onsemi 0:098463de4c5d 54 // pc.baud(9600);
group-onsemi 0:098463de4c5d 55
group-onsemi 0:098463de4c5d 56 // Use a deliberatly slow baud to fill up the TX buffer
group-onsemi 0:098463de4c5d 57 uart.baud(1200);
group-onsemi 0:098463de4c5d 58
group-onsemi 0:098463de4c5d 59 uart.attach(&txCallback, MODSERIAL::ModTxIrq);
group-onsemi 0:098463de4c5d 60 uart.attach(&rxCallback, MODSERIAL::ModRxIrq);
group-onsemi 0:098463de4c5d 61 uart.attach(&txEmpty, MODSERIAL::ModTxEmpty);
group-onsemi 0:098463de4c5d 62
group-onsemi 0:098463de4c5d 63 // Loop sending characters. We send 512
group-onsemi 0:098463de4c5d 64 // which is twice the default TX/RX buffer size.
group-onsemi 0:098463de4c5d 65
group-onsemi 0:098463de4c5d 66 led1 = 1; // Show start of sending with LED1.
group-onsemi 0:098463de4c5d 67
group-onsemi 0:098463de4c5d 68 for (int loop = 0; loop < 512; loop++) {
group-onsemi 0:098463de4c5d 69 uart.printf("%c", c);
group-onsemi 0:098463de4c5d 70 c++;
group-onsemi 0:098463de4c5d 71 if (c > 'Z') c = 'A';
group-onsemi 0:098463de4c5d 72 }
group-onsemi 0:098463de4c5d 73
group-onsemi 0:098463de4c5d 74 led1 = 0; // Show the end of sending by switching off LED1.
group-onsemi 0:098463de4c5d 75
group-onsemi 0:098463de4c5d 76 // End program. Flash LED4. Notice how LED 2 and 3 continue
group-onsemi 0:098463de4c5d 77 // to flash for a short period while the interrupt system
group-onsemi 0:098463de4c5d 78 // continues to send the characters left in the TX buffer.
group-onsemi 0:098463de4c5d 79
group-onsemi 0:098463de4c5d 80 while(1) {
group-onsemi 0:098463de4c5d 81 led4 = !led4;
group-onsemi 0:098463de4c5d 82 wait(0.25);
group-onsemi 0:098463de4c5d 83 }
group-onsemi 0:098463de4c5d 84 }
group-onsemi 0:098463de4c5d 85
group-onsemi 0:098463de4c5d 86 /*
group-onsemi 0:098463de4c5d 87 * Notes. Here is the sort of output you can expect on your PC/Mac/Linux host
group-onsemi 0:098463de4c5d 88 * machine that is connected to the "pc" USB serial port.
group-onsemi 0:098463de4c5d 89 *
group-onsemi 0:098463de4c5d 90 * ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUV
group-onsemi 0:098463de4c5d 91 * WXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQR
group-onsemi 0:098463de4c5d 92 * STUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMN
group-onsemi 0:098463de4c5d 93 * OPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJ
group-onsemi 0:098463de4c5d 94 * KLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEF
group-onsemi 0:098463de4c5d 95 * GHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZAB
group-onsemi 0:098463de4c5d 96 * CDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQ Done. R
group-onsemi 0:098463de4c5d 97 *
group-onsemi 0:098463de4c5d 98 * Of interest is that last "R" character after the system has said "Done."
group-onsemi 0:098463de4c5d 99 * This comes from the fact that the TxEmpty callback is made when the TX buffer
group-onsemi 0:098463de4c5d 100 * becomes empty. MODSERIAL makes use of the fact that the Uarts built into the
group-onsemi 0:098463de4c5d 101 * LPC17xx device use a 16 byte FIFO on both RX and TX channels. This means that
group-onsemi 0:098463de4c5d 102 * when the TxEmpty callback is made, the TX buffer is empty, but that just means
group-onsemi 0:098463de4c5d 103 * the "last few characters" were written to the TX FIFO. So although the TX
group-onsemi 0:098463de4c5d 104 * buffer has gone empty, the Uart's transmit system is still sending any remaining
group-onsemi 0:098463de4c5d 105 * characters from it's TX FIFO. If you want to be truely sure all the characters
group-onsemi 0:098463de4c5d 106 * you have sent have left the Mbed then call txIsBusy(); This function will
group-onsemi 0:098463de4c5d 107 * return true if characters are still being sent. If it returns false after
group-onsemi 0:098463de4c5d 108 * the Tx buffer is empty then all your characters have been sent.
group-onsemi 0:098463de4c5d 109 *
group-onsemi 0:098463de4c5d 110 * In a similar way, when characters are received into the RX FIFO, the entire
group-onsemi 0:098463de4c5d 111 * FIFO contents is moved to the RX buffer, assuming there is room left in the
group-onsemi 0:098463de4c5d 112 * RX buffer. If there is not, any remaining characters are left in the RX FIFO
group-onsemi 0:098463de4c5d 113 * and will be moved to the RX buffer on the next interrupt or when the running
group-onsemi 0:098463de4c5d 114 * program removes a character(s) from the RX buffer with the getc() method.
group-onsemi 0:098463de4c5d 115 */