wayne roberts / Mbed OS i2c_slave_block_example

example of i2c slave device supporting block transfers

Dependencies:   lib_i2c_slave_block

Tested on nucleo board as slave. Use with i2c_master_block_example on raspberry pi as master.

Master I2C write will print on serial terminal 115200. User button will raise an irq; the RPi test program will service the interrupt.

See lib_i2c_slave_block for explanation of code.

main.cpp@0:3ccfaf358115, 2019-01-18 (annotated)

Committer:
Wayne Roberts
Date:
Fri Jan 18 14:36:09 2019 -0800
Revision:
0:3ccfaf358115
Child:
2:d7e05c75f240
initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Wayne Roberts 0:3ccfaf358115 1
Wayne Roberts 0:3ccfaf358115 2 #include <mbed.h>
Wayne Roberts 0:3ccfaf358115 3 #include "smbus.h"
Wayne Roberts 0:3ccfaf358115 4 #include "cmds.h"
Wayne Roberts 0:3ccfaf358115 5
Wayne Roberts 0:3ccfaf358115 6 #define IRQ_OUT_PIN D6
Wayne Roberts 0:3ccfaf358115 7
Wayne Roberts 0:3ccfaf358115 8 const int SLAVE_ADDRESS = 0xA0;
Wayne Roberts 0:3ccfaf358115 9
Wayne Roberts 0:3ccfaf358115 10 RawSerial pc(USBTX, USBRX);
Wayne Roberts 0:3ccfaf358115 11
Wayne Roberts 0:3ccfaf358115 12 DigitalOut irqOutPin(IRQ_OUT_PIN);
Wayne Roberts 0:3ccfaf358115 13 irq_t irq;
Wayne Roberts 0:3ccfaf358115 14
Wayne Roberts 0:3ccfaf358115 15 DigitalIn button(USER_BUTTON);
Wayne Roberts 0:3ccfaf358115 16
Wayne Roberts 0:3ccfaf358115 17
Wayne Roberts 0:3ccfaf358115 18 void fill_tx_buf(uint8_t cmd)
Wayne Roberts 0:3ccfaf358115 19 {
Wayne Roberts 0:3ccfaf358115 20 static uint8_t cnt = 0;
Wayne Roberts 0:3ccfaf358115 21 unsigned i;
Wayne Roberts 0:3ccfaf358115 22
Wayne Roberts 0:3ccfaf358115 23 /* answering (master read) request here */
Wayne Roberts 0:3ccfaf358115 24
Wayne Roberts 0:3ccfaf358115 25 switch (cmd) {
Wayne Roberts 0:3ccfaf358115 26 case CMD_TEST3:
Wayne Roberts 0:3ccfaf358115 27 case CMD_TEST12:
Wayne Roberts 0:3ccfaf358115 28 case CMD_TEST32:
Wayne Roberts 0:3ccfaf358115 29 for (i = 0; i < cmd_to_length[cmd]; i++)
Wayne Roberts 0:3ccfaf358115 30 i2c.tx_buf[i] = i + cnt;
Wayne Roberts 0:3ccfaf358115 31 cnt++;
Wayne Roberts 0:3ccfaf358115 32 break;
Wayne Roberts 0:3ccfaf358115 33 case CMD_IRQ:
Wayne Roberts 0:3ccfaf358115 34 for (i = 0; i < cmd_to_length[CMD_IRQ]; i++)
Wayne Roberts 0:3ccfaf358115 35 i2c.tx_buf[i] = irq.buf[i];
Wayne Roberts 0:3ccfaf358115 36
Wayne Roberts 0:3ccfaf358115 37 /* interrupt was (is being) read, clear it */
Wayne Roberts 0:3ccfaf358115 38 irq.fields.flags.button = 0;
Wayne Roberts 0:3ccfaf358115 39 if (irq.buf[0] == 0)
Wayne Roberts 0:3ccfaf358115 40 irqOutPin = 0;
Wayne Roberts 0:3ccfaf358115 41
Wayne Roberts 0:3ccfaf358115 42 break;
Wayne Roberts 0:3ccfaf358115 43 }
Wayne Roberts 0:3ccfaf358115 44 }
Wayne Roberts 0:3ccfaf358115 45
Wayne Roberts 0:3ccfaf358115 46 void service_i2c_write(uint8_t cmd, uint8_t len, const uint8_t* req)
Wayne Roberts 0:3ccfaf358115 47 {
Wayne Roberts 0:3ccfaf358115 48 uint8_t s8;
Wayne Roberts 0:3ccfaf358115 49
Wayne Roberts 0:3ccfaf358115 50 /* taking master write here */
Wayne Roberts 0:3ccfaf358115 51
Wayne Roberts 0:3ccfaf358115 52 switch (cmd) {
Wayne Roberts 0:3ccfaf358115 53 case CMD_TEST3:
Wayne Roberts 0:3ccfaf358115 54 case CMD_TEST12:
Wayne Roberts 0:3ccfaf358115 55 case CMD_TEST32:
Wayne Roberts 0:3ccfaf358115 56 for (s8 = 0; s8 < cmd_to_length[cmd]; s8++)
Wayne Roberts 0:3ccfaf358115 57 pc.printf("%02x ", req[s8]);
Wayne Roberts 0:3ccfaf358115 58 pc.printf("\r\n");
Wayne Roberts 0:3ccfaf358115 59 break;
Wayne Roberts 0:3ccfaf358115 60 default:
Wayne Roberts 0:3ccfaf358115 61 pc.printf("??%02x??|\r\n", cmd);
Wayne Roberts 0:3ccfaf358115 62 break;
Wayne Roberts 0:3ccfaf358115 63 } // ..switch (cmd)
Wayne Roberts 0:3ccfaf358115 64 }
Wayne Roberts 0:3ccfaf358115 65
Wayne Roberts 0:3ccfaf358115 66 int main()
Wayne Roberts 0:3ccfaf358115 67 {
Wayne Roberts 0:3ccfaf358115 68 int res;
Wayne Roberts 0:3ccfaf358115 69 bool but;
Wayne Roberts 0:3ccfaf358115 70 uint8_t cnt = 0;
Wayne Roberts 0:3ccfaf358115 71
Wayne Roberts 0:3ccfaf358115 72 pc.baud(115200);
Wayne Roberts 0:3ccfaf358115 73 pc.printf("\r\nreset\r\n");
Wayne Roberts 0:3ccfaf358115 74
Wayne Roberts 0:3ccfaf358115 75 res = smbus_init(SLAVE_ADDRESS);
Wayne Roberts 0:3ccfaf358115 76 pc.printf("%d = smbus_init()\r\n", res);
Wayne Roberts 0:3ccfaf358115 77
Wayne Roberts 0:3ccfaf358115 78 but = button.read();
Wayne Roberts 0:3ccfaf358115 79 while (1) {
Wayne Roberts 0:3ccfaf358115 80 service_i2c();
Wayne Roberts 0:3ccfaf358115 81
Wayne Roberts 0:3ccfaf358115 82 if (but != button.read()) {
Wayne Roberts 0:3ccfaf358115 83 irq.fields.cnt = cnt++;
Wayne Roberts 0:3ccfaf358115 84 irq.fields.flags.button = 1;
Wayne Roberts 0:3ccfaf358115 85 irqOutPin = 1;
Wayne Roberts 0:3ccfaf358115 86
Wayne Roberts 0:3ccfaf358115 87 but = button.read();
Wayne Roberts 0:3ccfaf358115 88 }
Wayne Roberts 0:3ccfaf358115 89
Wayne Roberts 0:3ccfaf358115 90 } // ..while (1)
Wayne Roberts 0:3ccfaf358115 91 }
Wayne Roberts 0:3ccfaf358115 92