MOD-RS485-ISO
Contents
Description
MOD-RS485-ISO is smart RS485 transceiver. Data flow can be controlled via I2C bus.
Leds
The device has two leds:
- Green - Indicates TX channel is active
- Red - Indicates RX channel is active
By default both channels are active, so both leds should be on.
Registers
Register map starts at address 20h. There are 8 memory registers, that the user can access:
Device registers | |||
---|---|---|---|
Name | Address | Default | Description |
DeviceID | 20h | 25h | Device identifier |
Firmware | 21h | x | Indicate firmware revision, latest version is 03h |
Address | 22h | 22h | Writing to this register will change slave address of the device. |
Mode | 23h | 00h | Set device either in pass or bridge mode |
Control | 24h | 03h | Enable/Disable RX/TX channel |
Baudrate | 25h | 12h | Set default baudrate. Usable only in bridge mode. |
TX | 26h | x | Writing byte to this register will send data to RS-485 bus. Usable only in bridge mode. |
RX | 27h | x | Reading from this register will return incoming data from RS-485 bus. Usable inly in bridge mode. |
Modes of operation
The device has 2 modes of operation:
- Pass - What comes in that comes out, no mater modulation, baudrate, etc. This is the default mode of operation.
- Bridge - TX and RX pins are disconnected and all communication is done by the I2C bus. Writing byte to tx register will send it to RS485 bus. The baudrate is set to 115200.
Additionally you can disable data that goes from/to RS-485 bus. This can be done only by sending I2C message to the board. By default both directions are enabled.
Control data direction
By default data is enabled on both TX/RX channels. Writing 24h register can disable each one of them:
Control register | |||||||
---|---|---|---|---|---|---|---|
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
x | x | x | x | x | x | TX | RX |
- RX:
- 0 - Disable RX channel
- 1 - Enable RX channel
- TX:
- 0 - Disable TX channel
- 1 - Enable TX channel
Documents
Under construction
Hardware
Under construction
Software
Under construction
Older Firmware releases
Latest firmware is available at the main page of the device. In the wiki one can only find older firmware, that still might be helpful. The projects listed below are no longer officially supported. The best practice is to use the EXACT same compiler as mentioned and in most cases the exact same IDE version as mentioned.
Older firmware and examples based on older firmware, released by Olimex for MOD-RS485-ISO:
1) MOD-RS485-ISO v2 firmware - binary, source, and how-to - click to download
2)MOD-RS485-ISO v1 firmware - binary, source, and how-to - click to download
3)MOD-RS485-ISO v1 firmware + OLIMEXINO-328 - C source and HEX for I2C control - click to download
4)MOD-RS485-ISO v1 firmware + PIC-P26J50 demo code - C source and HEX for I2C control - click to download
Projects
Under construction
FAQ
Under construction