HUB75-Sinking_input

HUB-75 Sinking input

Break-out board with 12 channel sinking input. The FPGA is galvanically separated from field power using opto-couplers.

Features

• 2 HUB-75 output connectors
• 12 channel sinking output using JST connectors
• 5~24 V Field power with reverse polarity protection
• indicating LED for each output
• indicated switching frequency 1 kHz

Applications

• PNP (souring) limit switches
• Momentary push-buttons
• Slow encoders, for example for user input

NOTE
The PC827 optocouplers have a maximum rated frequency of 80 kHz. It is recommended to start at a frequency of 1 kHz and work up from there.

Example wiring

TODO: example

Litex-CNC example configuration

Let's assume that the two HUB-745 connectors on this board are connected to J15 and J16 of the FPGA. To configure the pins for output, you can use the configuration-block below as a starting point. Optionaly the pin names can also be set in the configuration, making the HAL clearer.

{
    ...,
    "gpio_in": [
        {"pin": "j15:0"},
        {"pin": "j15:1"},
        {"pin": "j15:2"},
        {"pin": "j15:4"},
        {"pin": "j15:5"},
        {"pin": "j15:6"},
        {"pin": "j16:0"},
        {"pin": "j16:1"},
        {"pin": "j16:2"},
        {"pin": "j16:4"},
        {"pin": "j16:5"},
        {"pin": "j16:6"}
    ],
    ...
}

Alternatively, the BOB can also be used for PWM output. In that case the configuration may look something like below. In this example it is assumed that outputs on J16 are used for three encoders.

{
    ...,
    "encoders": [
        {  
            "pin_A":"j16:0",
            "pin_B":"j16:1"
        },
        {  
            "pin_A":"j16:2",
            "pin_B":"j16:4"
        },
        {  
            "pin_A":"j16:5",
            "pin_B":"j16:6"
        }
    ],
    ...
}

Bill of materials

The table below gives the bill of materials used for this BOB and an indication of its price. The list is available as public list for the following companies:

• Reichtelt. This is non-affiliate link, I do not earn any money when you order this list from this specific vendor, nor the vendor endorses this project. Reichtelt is a supplyer for Western Europe.

When you order with Mouser or antohter supplier, please share a list here.

Part. number	Package	Description	Datasheet	Amount	Price*
LTV827	DIP-8	Dual-channel opto-coupler		6	€ 0.31
AO3401A	SOT-23	P-Channel MOSFET, 30V		1	€ 0.25
ZENER 12V	SOT-23	12V Zener diode***		1	€ 0.05
4.7K	SMD 1206	Resistor, 4.7 kOhm		12	€ 0.03
10K	SMD 1206	Resistor, 10 kOhm		1	€ 0.03
LED	SMD 1206	LED, green, If > 20 mA		12	€ 0.08
CAP 15N	SMD 1206	Capitor, 15 nF		1	€ 0.02
JST XH 3P	-	JST XH conn. 2.5 mm pitch		12	€ 0.15
DG250 3,5-2	-	Screw/spring terminal 2.5 mm pitch		2	€ 0.22
BOX 2X8	-	Box header 2x8, 2.54 mm pitch		2	€ 0.16
2N7002**	SOT-23	N-Channel MOSFET (current mirror)		13	€ 0.04
CL2N8-G**	SOT-89	LED-driver 20 mA (current mirror)		1	€ 0.39
R**	SMD 1206	Resistor, TBD Ohm (alternative)		12	€ 0.03

NOTES:

1. The price is based on availability in the Netherlands with a single shop for all parts. Parts might be sourced cheaper depending on your location, available sources and the time you want to wait before receiving the components.
2. The components CL2N8-G and 2N7002 form a current mirror for driving the status LEDs. This current mirror can be replaced with a fixed resistor R, which should be calculated based on the voltage used for Field power.
3. The zener diode is only required when Field Power is >12 Volt for protecting the MOSFETs.

Known issues

This board does not have any known issues yet.

If you find any issue, please file a bug using GitHub.