Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
en:calaos_io_controller [2015/08/21 19:32] nico [Hardware] |
en:calaos_io_controller [2015/08/23 14:25] nico [Calaos PLC IO] |
||
---|---|---|---|
Line 20: | Line 20: | ||
LEDs indicator? | LEDs indicator? | ||
+ | Schematics can be found here : https:// | ||
==== Bus ==== | ==== Bus ==== | ||
- | RS485 will be used as the principal bus to control the IOs on the board | + | RS485 will be used as the principal bus to control the IOs on the board. The components needed to use the bus are really cheap and the bus can withstand really long lines. |
==== Hardware ==== | ==== Hardware ==== | ||
The hardware is designed arround a tiny microcontroller. | The hardware is designed arround a tiny microcontroller. | ||
- | The folling | + | The following |
- STM32F0 (1,40€) | - STM32F0 (1,40€) | ||
- ATMEGA328 (3,20€) | - ATMEGA328 (3,20€) | ||
- | The IO are drived by a 2 GPIO exapanders | + | The IO are drived by a 2 GPIO expanders |
- PCA9505 is a gpio expander with 40 IOs | - PCA9505 is a gpio expander with 40 IOs | ||
Line 55: | Line 56: | ||
Modbus has the inconvenient of having a big overhead per packet and is used in systeme where the master need to access content of register of slaves. It's not designed with firmware upgrade of slaves in mind for example. | Modbus has the inconvenient of having a big overhead per packet and is used in systeme where the master need to access content of register of slaves. It's not designed with firmware upgrade of slaves in mind for example. | ||
+ | The frames will have the following format: | ||
+ | |||
+ | {{: | ||
+ | |||
+ | * Slave ID is a configurable id (through DIP switch or jumper) located on each sensors. | ||
+ | * The content is then application defined | ||
+ | {{: | ||
+ | {{: |