| 1 | /* bitbang_cbus.c |
| 2 | |
| 3 | Example to use CBUS bitbang mode of newer chipsets. |
| 4 | You must enable CBUS bitbang mode in the EEPROM first. |
| 5 | |
| 6 | Thanks to Steve Brown <sbrown@ewol.com> for the |
| 7 | the information how to do it. |
| 8 | |
| 9 | The top nibble controls input/output and the bottom nibble |
| 10 | controls the state of the lines set to output. The datasheet isn't clear |
| 11 | what happens if you set a bit in the output register when that line is |
| 12 | conditioned for input. This is described in more detail |
| 13 | in the FT232R bitbang app note. |
| 14 | |
| 15 | BITMASK |
| 16 | CBUS Bits |
| 17 | 3210 3210 |
| 18 | xxxx xxxx |
| 19 | | |------ Output Control 0->LO, 1->HI |
| 20 | |----------- Input/Output 0->Input, 1->Output |
| 21 | |
| 22 | Example: |
| 23 | All pins to output with 0 bit high: 0xF1 (11110001) |
| 24 | Bits 0 and 1 to input, 2 and 3 to output and masked high: 0xCC (11001100) |
| 25 | |
| 26 | The input is standard "0x" hex notation. |
| 27 | A carriage return terminates the program. |
| 28 | |
| 29 | This program is distributed under the GPL, version 2 |
| 30 | */ |
| 31 | |
| 32 | #include <stdio.h> |
| 33 | #include <unistd.h> |
| 34 | #include <stdlib.h> |
| 35 | #include <ftdi.h> |
| 36 | |
| 37 | int main(void) |
| 38 | { |
| 39 | struct ftdi_context *ftdi; |
| 40 | int f; |
| 41 | unsigned char buf[1]; |
| 42 | unsigned char bitmask; |
| 43 | char input[10]; |
| 44 | int retval = 0; |
| 45 | |
| 46 | if ((ftdi = ftdi_new()) == 0) |
| 47 | { |
| 48 | fprintf(stderr, "ftdi_new failed\n"); |
| 49 | return EXIT_FAILURE; |
| 50 | } |
| 51 | |
| 52 | f = ftdi_usb_open(ftdi, 0x0403, 0x6001); |
| 53 | if (f < 0 && f != -5) |
| 54 | { |
| 55 | fprintf(stderr, "unable to open ftdi device: %d (%s)\n", f, ftdi_get_error_string(ftdi)); |
| 56 | ftdi_deinit(ftdi); |
| 57 | exit(-1); |
| 58 | } |
| 59 | printf("ftdi open succeeded: %d\n",f); |
| 60 | |
| 61 | while (1) |
| 62 | { |
| 63 | // Set bitmask from input |
| 64 | fgets(input, sizeof(input) - 1, stdin); |
| 65 | if (input[0] == '\n') break; |
| 66 | bitmask = strtol(input, NULL, 0); |
| 67 | printf("Using bitmask 0x%02x\n", bitmask); |
| 68 | f = ftdi_set_bitmode(ftdi, bitmask, BITMODE_CBUS); |
| 69 | if (f < 0) |
| 70 | { |
| 71 | fprintf(stderr, "set_bitmode failed for 0x%x, error %d (%s)\n", bitmask, f, ftdi_get_error_string(ftdi)); |
| 72 | ftdi_usb_close(ftdi); |
| 73 | ftdi_deinit(ftdi); |
| 74 | retval = -1; |
| 75 | } |
| 76 | |
| 77 | // read CBUS |
| 78 | f = ftdi_read_pins(ftdi, &buf[0]); |
| 79 | if (f < 0) |
| 80 | { |
| 81 | fprintf(stderr, "read_pins failed, error %d (%s)\n", f, ftdi_get_error_string(ftdi)); |
| 82 | ftdi_usb_close(ftdi); |
| 83 | ftdi_deinit(ftdi); |
| 84 | exit(-1); |
| 85 | } |
| 86 | printf("Read returned 0x%01x\n", buf[0] & 0x0f); |
| 87 | } |
| 88 | printf("disabling bitbang mode\n"); |
| 89 | ftdi_disable_bitbang(ftdi); |
| 90 | |
| 91 | ftdi_usb_close(ftdi); |
| 92 | ftdi_free(ftdi); |
| 93 | |
| 94 | return 0; |
| 95 | } |