BOB4STEPGEN

[Peter-van-Tol]

In this topic we can discuss the BOB4STEPGEN daughter board. This board has now been produced with 10 pieces of version 1.0 and a subsequent series of 5 boards of version 1.1.

CHANGELOG:

• version 1.0:
  • Initial version
• version 1.1:
  • In version 1.0 an error was discovered: when the HUB75HAT is disabled, the ENA of the stepgen was left floating. This might lead to unpredictable behavior when the HUB75HAT is disabled. To solve this, a resistor between ENA and ground has been added to the board.

Sample configuration
This example shows the configuration for a BOB4STEPGEN located on J1:

{
    "board_name": "BOB4STEPGEN",
    "board_type": "HUB75HAT v8.0",
    "clock_frequency": 35000000,
    "connection": {
        "connection_type": "spi",
        "mosi": "spi:0",
        "miso": "spi:1",
        "clk":  "spi:2",
        "cs_n": "spi:3"
    },
    "watchdog": {
        "pin":"ena:0"
    },
    "modules": [
        {
            "module_type": "gpio",
            "instances": [
                {"direction": "out", "pin":"j1:1" , "name":"STEPGEN_ENA"},
                {"direction": "in",  "pin":"j1:10", "name":"AXIS1_OK"   },
                {"direction": "in",  "pin":"j1:11", "name":"AXIS2_OK"   },
                {"direction": "in",  "pin":"j1:12", "name":"AXIS3_OK"   },
                {"direction": "in",  "pin":"j1:13", "name":"AXIS4_OK"   },
                {"direction": "in",  "pin":"j1:14", "name":"AXIS1_HOME" },
                {"direction": "in",  "pin":"j1:15", "name":"AXIS2_HOME" },
                {"direction": "in",  "pin":"j1:16", "name":"AXIS3_HOME" },
                {"direction": "in",  "pin":"j1:17", "name":"AXIS4_HOME" }
            ]
        },
        {
            "module_type": "stepgen",
            "instances": [
                {
                    "name" : "AXIS1",
                    "pins" : {
                        "stepgen_type": "step_dir",
                        "step_pin": "j1:2",
                        "dir_pin": "j1:6"
                    },
                    "soft_stop": true
                },{
                    "name" : "AXIS2",
                    "pins" : {
                        "stepgen_type": "step_dir",
                        "step_pin": "j1:3",
                        "dir_pin": "j1:7"
                    },
                    "soft_stop": true
                },{
                    "name" : "AXIS3",
                    "pins" : {
                        "stepgen_type": "step_dir",
                        "step_pin": "j1:4",
                        "dir_pin": "j1:8"
                    },
                    "soft_stop": true
                },{
                    "name" : "AXIS4",
                    "pins" : {
                        "stepgen_type": "step_dir",
                        "step_pin": "j1:5",
                        "dir_pin": "j1:9"
                    },
                    "soft_stop": true
                }
            ]
        }
    ]
}

NOTES:

• the AXIS#_HOME is active LOW. You might need to use the HAL pin in-not for your homing sequence.
• the AXIS#_OK will be LOW when an error has been detected. Based on Leadshine DM556: The resistance between ALM+ and ALM- is low impedance as default, and will changetohigh when the drive goes into error protection.. This means that the drive 'cuts' the connection between ALARM+ and ALARM-, leading to a low signal.