DatasheetsPDF.com

SRF01 Dataheets PDF



Part Number SRF01
Manufacturers ETC
Logo ETC
Description Ultrasonic range finder
Datasheet SRF01 DatasheetSRF01 Datasheet (PDF)

SRF01 Ultrasonic range finder Technical Documentation Overview The SRF01 is a single transducer ultrasonic rangefinder in a very small footprint PCB. Connection is to a single pin Serial interface. The serial interface is a standard TTL level UART format of 1 start, 1 stop and no parity bits, and may be connected directly to many controllers, such as the Basic Stamps or the PICAXE. Baud rate at power-up is always 9600, there is a command to change this to 19200 or 38400 baud if preferred. Up to.

  SRF01   SRF01


Document
SRF01 Ultrasonic range finder Technical Documentation Overview The SRF01 is a single transducer ultrasonic rangefinder in a very small footprint PCB. Connection is to a single pin Serial interface. The serial interface is a standard TTL level UART format of 1 start, 1 stop and no parity bits, and may be connected directly to many controllers, such as the Basic Stamps or the PICAXE. Baud rate at power-up is always 9600, there is a command to change this to 19200 or 38400 baud if preferred. Up to 16 SRF01's may be connected together on a single bus. Like all our rangefinders, the SRF01 can measure in Cm or Inches. Power Requirements The SRF01 accepts any voltage between 3.3v and 12v, however the recommended maximum is 5.5v. Internally, it operates at 3.3v and there is a low dropout regulator already on the SRF01 to provide this. The serial I/O pin operates at 3.3v and also 5v tolerant, so you can connect it directly to 3.3v or 5v signals. Operating current during ranging is 25mA, 11mA in standby (waiting for a command) and around 55uA in sleep mode (shutdown). Single Pin Serial Communication Serial data is 1 start, 1 stop and no parity bits. Serial data is a TTL level signal - It is NOT RS232. Do not connect the SRF01 to an RS232 port - you will destroy the module! Communication with the SRF01 is with both serial input and serial output on a single pin. The SRF01 will be listening at all times except when it is actually sending data, and will go back to listening as soon as its finished. To communicate with the SRF01, you simply need to send a "break", followed by two bytes, the address of the SRF01 (factory default is 1) and the command. A "break" is just a low level for 12 bit times or longer. 1.5mS or more will be fine. It is used to synchronize transfers on the 1-wire serial bus. The default shipped address can be changed by the user to any of 16 addresses 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16, and therefore up to 16 sonar's can be used. Note - this range is different to the SRF02 which has addresses 0-15. The reason is that for specific commands only all SRF01's regardless of their programmed address, will respond to address 0. This makes it easy to start all SRF01s ranging at the same time. Baud Rate The serial baud rate on the SRF01 always starts at 9600 on power up. It can be changed to 19200 or 38400 if you wish. It will revert to 9600 at the next power up. To change the baud rate, just send a "break" followed by the general call address of zero (not the module address), then command 0x64 for 19200 or command 0x65 for 38400. You can only send the command to address zero to change all SRF01's at the same time. Connections The connections to the SRF01 are shown below. If you're using multiple SRF01's, you can connect them all up to the same serial port on your controller. Just make sure all the SRF01's are programmed to different addresses. There is a weak pull-up resistor (47k) to 3.3v on the module, to pull the Tx line up to a logic high level when none of the SRF01's are transmitting. Our 3-way JST connectors are suitable for connecting the SRF01. Commands To send a command to the SRF01, you need to send a "break" followed by two bytes. The first is the SRF01's address 1 to 16, (0x01 to 0x10) and then the actual command itself - see below. There are two commands to initiate a ranging (80 to 81) giving results in inches and centimeters. These two commands don't Transmit the result back to your controller. You should wait 70mS and then use command 94 to get the result of the ranging. Another set of two commands (83 to 84) do the same, but also transmits the result of the ranging back to your controller as soon as it is available. Together, these four commands (80,81,84 & 84) are called "Real" because they perform a complete ranging. There is another set of four commands (86, 87, 89 & 90) called "Fake". They are the same as the "Real" commands except that they do not send the 8-cycle ultrasonic burst out. These are used where the burst has been transmitted by another sonar. It is up to you to synchronize the commands to the two sonar's. There is a command (92) to transmit a burst without doing the ranging. Command 93 is used to get the firmware revision of the SRF01. Command 94 gets returns two bytes (high byte first) from the most recent ranging. Put them together to make a 16-bit result. Command 95 gets the status byte. Bit 0 is the "Lock" bit. it is low (0) after power up, after the "Unlock" command is executed and after the module exits sleep mode. It goes high after 6 rangings have been completed with at least 30cm of free space in front of the sonar. See Advanced Mode for more details. Command 96 is used to place the SRF01 in a low power sleep mode. See Sleep Mode for more details. Commands 98 & 99 are used to enable/disable Advanced Mode. Command Decimal Hex 80 0x50 81 0x51 83 84 86 87 0x53 0x54 0x56 0x57 Address 0 Action Access Yes Real Ranging Mode - Result in inches Yes R.


V230W1-L02 SRF01 DP47840


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)