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| | My hobby is programming embedded systems and creating my own small electronic boards. | | My hobby is programming embedded systems and creating my own small electronic boards. |
| | | | |
| − | === Skills ===
| + | == Skills == |
| | * Assembly programming: PIC 8bit family | | * Assembly programming: PIC 8bit family |
| | * C programming: PIC 8bit / PIC32MX family, Linux | | * C programming: PIC 8bit / PIC32MX family, Linux |
| Line 12: |
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| | * IP networking | | * IP networking |
| | | | |
| − | === My ArmadeuS plans (APF28 based) ===
| + | == My ArmadeuS plans (APF28 based) == |
| | * Creating an universal home automation hardware for my friends, with easy programming in perl or PHP. :) | | * Creating an universal home automation hardware for my friends, with easy programming in perl or PHP. :) |
| | * Datacenter temperature monitoring, with RS-485 and OneWire communications. | | * Datacenter temperature monitoring, with RS-485 and OneWire communications. |
| | * Data logger for Saia Sbus based intelligent power meters. | | * Data logger for Saia Sbus based intelligent power meters. |
| | | | |
| − | | + | == My works comitted to ArmadeuS project == |
| − | | + | * [[RS-485]] for APF28/iMX28 mxs-auart and busybox stty patch |
| − | | + | * [[OneWire GPIO bus Master]] for APF28DEV |
| − | == RS485 == | + | |
| − | Informations and mini HOWTOs for my APF28/iMX28 mxs-auart and busybox stty patches.
| + | |
| − | | + | |
| − | | + | |
| − | === Linux stty ===
| + | |
| − | * Setup APF28 serial port for RS485 communication:
| + | |
| − | <pre class=apf>
| + | |
| − | # stty -F /dev/ttySP0 raw
| + | |
| − | # stty -F /dev/ttySP0 -echo -echoe -echok
| + | |
| − | # stty -F /dev/ttySP0 rs485
| + | |
| − | </pre>
| + | |
| − | | + | |
| − | * Set extra delays for TXEN/RTS signaling before and after the transmitted packet (in microseconds):
| + | |
| − | <pre class=apf>
| + | |
| − | # stty -F /dev/ttySP0 rs485delaybefore 100
| + | |
| − | # stty -F /dev/ttySP0 rs485delayafter 100
| + | |
| − | </pre>
| + | |
| − | | + | |
| − | * To get current RS485 parameters. (If the port device supports the RS485 options you will see the last two lines)
| + | |
| − | <pre class=apf>
| + | |
| − | # stty -F /dev/ttySP0
| + | |
| − | speed 9600 baud; line = 0;
| + | |
| − | intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
| + | |
| − | eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
| + | |
| − | werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
| + | |
| − | -brkint -imaxbel
| + | |
| − | rs485 -rs485rtsonsend -rs485rtsaftersend -rs485rxduringtx
| + | |
| − | rs485delaybefore = 100; rs485delayafter = 100; rs485delaylastchartx = 1250;
| + | |
| − | </pre>
| + | |
| − | Please note:
| + | |
| − | * You can't set the "rs485delaylastchartx" parameter, it's calculated automatically from the baudrate.
| + | |
| − | Special notes for the APF28/iMX28 mxs-auart driver:
| + | |
| − | * All delays are in microseconds.
| + | |
| − | * The "rs485delaylastchartx" parameter is not used in DMA mode.
| + | |
| − | * The parameters: "rs485rtsonsend" "rs485rtsaftersend" "rs485rxduringtx" are not used. (Only used by atmel_serial.c and crisv10.c drivers)
| + | |
| − | * If the RS485 mode is turned on, it will override (turn off) the RTS/CTS hardware flow settings of the uart, don't care what is configured.
| + | |
| − | | + | |
| − | | + | |
| − | === C code ===
| + | |
| − | * The RS485 mode can be turned on with ioctl calls from C code, here is the example:
| + | |
| − | <source lang="C">
| + | |
| − | #include <stdio.h>
| + | |
| − | #include <fcntl.h>
| + | |
| − | #include <linux/ioctl.h>
| + | |
| − | #include <linux/serial.h>
| + | |
| − | #include <asm-generic/ioctls.h> /* TIOCGRS485 + TIOCSRS485 ioctl definitions */
| + | |
| − | | + | |
| − | int main(void) {
| + | |
| − | struct serial_rs485 rs485conf;
| + | |
| − | | + | |
| − | int fd = open ("/dev/ttySP0", O_RDWR);
| + | |
| − | if (fd < 0) {
| + | |
| − | printf("Error: Can't open: /dev/ttySP0\n");
| + | |
| − | }
| + | |
| − | | + | |
| − | | + | |
| − | /* Don't forget to read first the current state of the RS485 options with ioctl.
| + | |
| − | If You don't do this, You will destroy the rs485conf.delay_rts_last_char_tx
| + | |
| − | parameter which is automatically calculated by the driver when You opens the
| + | |
| − | port device. */
| + | |
| − | if (ioctl (fd, TIOCGRS485, &rs485conf) < 0) {
| + | |
| − | printf("Error: TIOCGRS485 ioctl not supported.\n");
| + | |
| − | }
| + | |
| − | | + | |
| − | /* Enable RS485 mode: */
| + | |
| − | rs485conf.flags |= SER_RS485_ENABLED;
| + | |
| − | | + | |
| − | /* Set rts/txen delay before send, if needed: (in microseconds) */
| + | |
| − | rs485conf.delay_rts_before_send = 0;
| + | |
| − | | + | |
| − | /* Set rts/txen delay after send, if needed: (in microseconds) */
| + | |
| − | rs485conf.delay_rts_after_send = 0;
| + | |
| − | | + | |
| − | if (ioctl (fd, TIOCSRS485, &rs485conf) < 0) {
| + | |
| − | printf("Error: TIOCSRS485 ioctl not supported.\n");
| + | |
| − | }
| + | |
| − | | + | |
| − | fcntl(fd, F_SETFL, 0);
| + | |
| − | int n = write(fd, "ABC\r\n", 5);
| + | |
| − | if (n < 0) {
| + | |
| − | /* Error handling */
| + | |
| − | }
| + | |
| − | | + | |
| − | if (close (fd) < 0) {
| + | |
| − | printf("Error: Can't close: /dev/ttySP0\n");
| + | |
| − | }
| + | |
| − | }
| + | |
| − | </source>
| + | |
| − | | + | |
| − | | + | |
| − | === Hardware Notes ===
| + | |
| − | * The RS485 Transmit Enable (TXEN) output will be the RTS pin of the uart.
| + | |
| − | * The TXEN/RTS output is _active low_, it must be inverted to use it with the popular RS485 transceiver ICs.
| + | |
| − | * When the u-boot runs and the board start to boot, the RTS pin works as input, please add a pullup resistor to this pin before the inverter, to prevent RS485 bus lockups.
| + | |
| − | | + | |
| − | | + | |
| − | | + | |
| − | | + | |
| − | == OneWire ==
| + | |
| − | Informations and mini HOWTOs for my APF28DEV OneWire patch.
| + | |
| − | | + | |
| − | | + | |
| − | === Software installation ===
| + | |
| − | * Recompile your Linux kernel with OneWire GPIO bus master (and some slave device) support. | + | |
| − | * The driver works only in static compiled mode. (Load as module did not work.)
| + | |
| − | <pre class="host">
| + | |
| − | $ make linux-menuconfig
| + | |
| − | </pre>
| + | |
| − | <pre class="config">
| + | |
| − | Device Drivers --->
| + | |
| − | <*> Dallas's 1-wire support --->
| + | |
| − | 1-wire Bus Masters --->
| + | |
| − | <*> GPIO 1-wire busmaster
| + | |
| − | 1-wire Slaves --->
| + | |
| − | <*> Thermal family implementation
| + | |
| − | </pre>
| + | |
| − | <pre class="host">
| + | |
| − | $ make
| + | |
| − | </pre>
| + | |
| − | * Reflash your Linux kernel
| + | |
| − | | + | |
| − | | + | |
| − | === Hardware Notes ===
| + | |
| − | * Connect the OneWire slave directly to the APF28_DEV board J9 connector:
| + | |
| − | * Vcc 3.3V is pin 1 on J9 connector
| + | |
| − | * DQ is pin 31 on J9 (LCD_D18 / GPIO 1_18)
| + | |
| − | * GND is pin 39 on J9
| + | |
| − | * Add an 1.2k pullup resistor between Vcc and DQ
| + | |
| − | | + | |
| − | | + | |
| − | === How it works ===
| + | |
| − | The OneWire bus master driver every 10 seconds scan the bus for new slave devices.
| + | |
| − | | + | |
| − | Each detected OneWire slave device have a sub-directory with it's unique ID in "/sys/devices/w1 bus master".
| + | |
| − | | + | |
| − | The sub-directory format is <2 digit family ID>-<12 digit unique ID>.
| + | |
| − | <pre class=apf>
| + | |
| − | # ls -la /sys/devices/w1\ bus\ master/
| + | |
| − | total 0
| + | |
| − | drwxr-xr-x 4 root root 0 Jan 1 01:06 .
| + | |
| − | drwxr-xr-x 6 root root 0 Jan 1 01:05 ..
| + | |
| − | drwxr-xr-x 3 root root 0 Jan 1 01:06 28-000001e68904
| + | |
| − | lrwxrwxrwx 1 root root 0 Jan 1 01:07 driver -> ../../bus/w1/drivers/w1_master_driver
| + | |
| − | drwxr-xr-x 2 root root 0 Jan 1 01:07 power
| + | |
| − | lrwxrwxrwx 1 root root 0 Jan 1 01:07 subsystem -> ../../bus/w1
| + | |
| − | -rw-r--r-- 1 root root 4096 Jan 1 01:07 uevent
| + | |
| − | -rw-rw-rw- 1 root root 4096 Jan 1 01:07 w1_master_add
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_attempts
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_max_slave_count
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_name
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_pointer
| + | |
| − | -rw-rw-rw- 1 root root 4096 Jan 1 01:07 w1_master_pullup
| + | |
| − | -rw-rw-rw- 1 root root 4096 Jan 1 01:07 w1_master_remove
| + | |
| − | -rw-rw-rw- 1 root root 4096 Jan 1 01:07 w1_master_search
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_slave_count
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_slaves
| + | |
| − | -r--r--r-- 1 root root 4096 Jan 1 01:07 w1_master_timeout
| + | |
| − | </pre>
| + | |
| − | You can list the detected slaves from this files:
| + | |
| − | <pre class=apf>
| + | |
| − | # cat /sys/devices/w1\ bus\ master/w1_master_slave_count
| + | |
| − | 1
| + | |
| − | # cat /sys/devices/w1\ bus\ master/w1_master_slaves
| + | |
| − | 28-000001e68904
| + | |
| − | </pre>
| + | |
| − | Let's read the temperature: (The 28-xxx family is a DS18B20 temperature sensor in this example.)
| + | |
| − | <pre class=apf>
| + | |
| − | # cat /sys/devices/w1\ bus\ master/28-000001e68904/w1_slave
| + | |
| − | dd 01 4b 46 7f ff 03 10 1e : crc=1e YES
| + | |
| − | dd 01 4b 46 7f ff 03 10 1e t=29812
| + | |
| − | </pre>
| + | |
| − | The t=29812 means, the temperature is: 29.812°C
| + | |
I am IP Network and Datacenter engineer, currently I'm working for an Internet Service Provider in Hungary.
My hobby is programming embedded systems and creating my own small electronic boards.
